Version July 2025
Ensure accuracy when prescribing, dispensing, and administering acetaminophen/codeine oral solution. Dosing errors due to confusion between mg and mL and other codeine-containing oral products of different concentrations can result in accidental overdose and death.
Because the use of acetaminophen/codeine exposes patients and other users to the risks of opioid addiction, abuse, and misuse, which can lead to overdose and death, assess each patient's risk prior to prescribing and reassess all patients regularly for the development of these behaviors and conditions.
Health care providers are strongly encouraged to complete a REMS-compliant education program and to counsel patients and caregivers on serious risks, safe use, and the importance of reading the Medication Guide with each prescription.
Serious, life-threatening, or fatal respiratory depression may occur with use of acetaminophen/codeine, especially during initiation or following a dose increase. To reduce the risk of respiratory depression, proper dosing and titration of acetaminophen/codeine are essential.
Accidental ingestion of even one dose of acetaminophen/codeine, especially by children, can result in a fatal overdose of acetaminophen/codeine.
Life-threatening respiratory depression and death have occurred in children who received codeine. Most of the reported cases occurred following tonsillectomy and/or adenoidectomy, and many of the children had evidence of being ultra-rapid metabolizers of codeine due to a CYP450 2D6 polymorphism. Acetaminophen/codeine is contraindicated in pediatric patients <12 years of age and in pediatric patients <18 years of age following tonsillectomy and/or adenoidectomy. Avoid the use of acetaminophen/codeine in pediatric patients 12 to 18 years of age who have other risk factors that may increase their sensitivity to the respiratory depressant effects of codeine.
If opioid use is required for an extended period of time in a pregnant woman, advise the patient of the risk of neonatal opioid withdrawal syndrome (NOWS), which may be life-threatening if not recognized and treated. Ensure that management by neonatology experts will be available at delivery.
Acetaminophen has been associated with cases of acute liver failure, at times resulting in liver transplant and death. Most of the cases of liver injury are associated with the use of acetaminophen at dosages that exceed 4 g/day, and often involve more than one acetaminophen-containing product.
The effects of concomitant use or discontinuation of CYP450 3A4 inducers, 3A4 inhibitors, or 2D6 inhibitors with codeine are complex. Use of CYP450 3A4 inducers, 3A4 inhibitors, or 2D6 inhibitors with acetaminophen/codeine requires careful consideration of the effects on the parent drug, codeine, and the active metabolite, morphine.
Concomitant use of opioids with benzodiazepines or other CNS depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of acetaminophen/codeine and benzodiazepines or other CNS depressants for use in patients for whom alternative treatment options are inadequate.
Dosage guidance:
Dosage form information: Multiple concentrations of oral liquid products may be available, particularly in international markets. In the United States (US), an oral solution containing acetaminophen 120 mg/codeine 12 mg per 5 mL is approved for use in adults only. In Canada, an oral syrup that contains acetaminophen 160 mg/codeine 8 mg per 5 mL is available. Medication orders (prescriptions) should have the concentration specified as well as the dose clearly represented as milligram (mg) of acetaminophen and mg of codeine, not volume (mL). Use caution to avoid confusion between different concentrations when prescribing and dispensing.
Safety: Consider all sources of acetaminophen (eg, prescription, OTC, combination products) when evaluating a patient's maximum daily dose. To lower the risk for hepatotoxicity, limit daily dose to ≤75 mg/kg/day (maximum of 5 daily doses), not to exceed 4,000 mg/day. While recommended doses of acetaminophen are generally considered safe, hepatotoxicity has been reported rarely, even with doses below recommendations (Ref).
Clinical considerations: Dosing provided below is based on Canadian product labeling. There are no US products containing acetaminophen and codeine currently approved for use in pediatric patients.
Pain management, mild to moderate:
Note: Use is contraindicated in pediatric patients <12 years of age and for postoperative management in pediatric patients 12 to 18 years of age who have undergone tonsillectomy and/or adenoidectomy. Avoid codeine use in all pediatric patient populations in which it is contraindicated and in pediatric patients 12 to 18 years of age who have other risk factors that increase risk for respiratory depression associated with codeine (eg, conditions associated with hypoventilation like postoperative status, obstructive sleep apnea, obesity, severe pulmonary disease, neuromuscular disease, use of other medications known to depress respiratory drive). Codeine has been associated with reports of life-threatening or fatal respiratory depression in children and adolescents; multifactorial causes have been identified; of primary concern are unrecognized ultrarapid metabolizers of CYP2D6 who may have extensive conversion of codeine (prodrug) to morphine and thus increased opioid-mediated effects (Ref).
Children ≥12 years and Adolescents: Oral: Not a preferred agent due to safety concerns and available alternatives; in rare cases in which codeine-containing product is the only option, consider genotype testing prior to use; use extra precaution; monitor closely for adverse effects. See individual agents for dosing.
Canadian labeling : Oral liquid: Acetaminophen 160 mg/codeine 8 mg per 5 mL [Canadian product]: Oral: 10 to 20 mL (acetaminophen 320 mg/codeine 16 mg to acetaminophen 640 mg/codeine 32 mg) every 4 to 6 hours as needed, not to exceed 5 doses/day; adjust dose according to severity of pain and response of patient; maximum daily dose: 100 mL per 24 hours (acetaminophen 3,200 mg/codeine 160 mg per 24 hours).
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
Children ≥12 years and Adolescents: There are no specific dosage adjustments provided in the manufacturer's labeling; however, clearance may be reduced; active metabolites may accumulate. Use with caution; initiate at lower doses or longer dosing intervals followed by careful titration (Ref). See individual monographs for specific adjustments.
Children ≥12 years and Adolescents: There are no dosage adjustments provided in the manufacturer's labeling; however, product contains acetaminophen; use with caution. Cases of hepatotoxicity at daily acetaminophen dosages <4 g/day have been reported (Ref). See individual monographs.
(For additional information see "Acetaminophen (paracetamol) and codeine: Drug information")
Dosage guidance:
Safety: Adult doses of codeine ≥60 mg fail to give commensurate relief of pain but merely prolong analgesia and are associated with an appreciably increased incidence of side effects. Consider prescribing naloxone or nalmefene for patients with factors associated with an increased risk for overdose, such as history of overdose or substance use disorder, patients with sleep-disordered breathing, higher opioid dosages (≥50 morphine milligram equivalents [MME]/day orally), and/or concomitant benzodiazepine use (Ref).
Dosing: Dosing provided is based on typical doses; some patients may require higher or lower doses. Individualize dosing based on patient-specific factors (eg, severity of pain, comorbidities, degree of opioid experience/tolerance) and titrate to patient-specific treatment goals (eg, improvement in function and quality of life, decrease in pain using a validated pain rating scale). Use the lowest effective dose for the shortest period of time.
Clinical considerations: Opioids may be part of a comprehensive, multimodal, patient-specific treatment plan for managing severe pain. Maximize nonopioid analgesia (when appropriate) prior to initiation of opioid analgesia (Ref).
Pain management: Oral:
Solution:
Acetaminophen 120 mg/codeine 12 mg per 5 mL: 15 mL every 4 hours as needed; adjust dose according to severity of pain and response of patient (maximum: acetaminophen 4,000 mg per 24 hours).
Acetaminophen 160 mg/codeine 8 mg per 5 mL [Canadian product]: 10 to 20 mL every 4 hours as needed; adjust dose according to severity of pain and response of patient (maximum: 100 mL per 24 hours)
Tablets: Acetaminophen (300 to 1,000 mg/dose)/codeine (15 to 60 mg/dose) every 4 hours as needed; adjust dose according to severity of pain and response of patient (maximum: acetaminophen 4,000 mg/codeine 360 mg per 24 hours).
Discontinuation of therapy: When reducing the dose, discontinuing, or tapering long-term opioid therapy, the dose should be gradually tapered. An optimal tapering schedule has not been established. Individualize tapering based on discussions with patient to minimize withdrawal, while considering patient-specific goals and concerns and the opioid’s pharmacokinetics. Proposed initial schedules range from slow (eg, 10% reduction per week or 10% reduction per month depending on duration of long-term therapy) to rapid (eg, 25% to 50% reduction every few days) (Ref). Slower tapers may be appropriate after long-term use (eg, >1 year), whereas more rapid tapers may be appropriate in patients experiencing severe adverse effects. During tapering, patients may be at an increased risk of overdose if they return to their original (or higher) opioid dose or use illicit opioids, due to rapid loss of tolerance; consider prescribing naloxone or nalmefene. Monitor carefully for signs/symptoms of withdrawal. If the patient displays withdrawal symptoms, consider slowing the taper schedule; alterations may include increasing the interval between dose reductions, decreasing amount of daily dose reduction, pausing the taper and restarting when the patient is ready, and/or coadministration of an alpha-2 agonist (eg, clonidine) to blunt autonomic withdrawal symptoms and other adjunctive agents to treat GI symptoms and muscle spasms, as needed. Continue to offer nonopioid analgesics as needed for pain management during the taper (Ref).
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
The renal dosing recommendations are based upon the best available evidence and clinical expertise. Senior Editorial Team: Bruce Mueller, PharmD, FCCP, FASN, FNKF; Jason A. Roberts, PhD, BPharm (Hons), B App Sc, FSHP, FISAC; Michael Heung, MD, MS.
Altered kidney function: Oral: There are no dosage adjustments provided in the manufacturer's labeling. Codeine dose adjustment or avoidance may be required based on degree of kidney impairment. See individual agents for more details. Codeine and its metabolites (including morphine-3-glucuronide and morphine-6-glucuronide) are eliminated by the kidneys. Patients with chronic kidney disease who are ultra-rapid metabolizers of codeine are at greatest risk of neurotoxic effects (Ref).
There are no specific dosage adjustments provided in the manufacturer's labeling; use with caution. Also see individual agents.
The following adverse drug reactions are derived from product labeling unless otherwise specified. Also see individual agents.
Frequency not defined:
Cardiovascular: Flushing
Dermatologic: Pruritus, skin rash, urticaria
Endocrine & metabolic: Adrenocortical insufficiency
Gastrointestinal: Abdominal pain, constipation, dyspepsia, nausea, vomiting
Hematologic & oncologic: Agranulocytosis, thrombocytopenia
Hepatic: Hepatotoxicity, increased serum transaminases
Hypersensitivity: Hypersensitivity reaction (including anaphylaxis, angioedema)
Nervous system: Agitation, dizziness, drowsiness, drug abuse, dysphoria, euphoria, neonatal withdrawal, opioid dependence, sedated state, serotonin syndrome
Respiratory: Dyspnea, respiratory depression
Postmarketing:
Genitourinary: Hypogonadism (Brennan 2013; Debono 2011)
Nervous system: Allodynia (opioid-induced hyperalgesia) (FDA Safety Communication 2023)
Hypersensitivity (eg, anaphylaxis) to acetaminophen, codeine, or any component of the formulation; pediatric patients <12 years of age; postoperative management in pediatric patients <18 years of age who have undergone tonsillectomy and/or adenoidectomy; significant respiratory depression; acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment; GI obstruction, including paralytic ileus (known or suspected); concurrent use with or within 14 days following monoamine oxidase inhibitors (MAOIs) therapy.
Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
Canadian labeling: Additional contraindications (not in US labeling): Hypersensitivity to other opioid analgesics; mechanical GI obstruction (eg, bowel obstruction, strictures) or any disease/condition that affects bowel transit (known or suspected); suspected surgical abdomen (eg, acute appendicitis, pancreatitis); mild pain that can be managed with other pain medications; severe hepatic or renal impairment; acute or severe bronchial asthma, chronic obstructive airway disease; status asthmaticus; hypercapnia; cor pulmonale; acute alcoholism; delirium tremens; seizure disorder; severe CNS depression; increased cerebrospinal or intracranial pressure; head injury; pregnancy; use during labor and delivery; CYP2D6 ultra-rapid metabolizers. Some products may contraindicate use in patients <18 years (refer to specific product labeling).
Concerns related to adverse effects:
• CNS depression: May cause CNS depression, which may impair physical or mental abilities; patients must be cautioned about performing tasks that require mental alertness (eg, operating machinery or driving).
• Constipation: May cause or aggravate constipation; chronic use may result in obstructive bowel disease, particularly in those with underlying intestinal motility disorders. May also be problematic in patients with unstable angina and patients post-myocardial infarction (MI). Consider preventive measures (eg, stool softener, increased fiber) to reduce the potential for constipation.
• Hepatotoxicity: Acetaminophen has been associated with cases of acute liver failure, at times resulting in liver transplant and death. Most of the cases of liver injury are associated with the use of acetaminophen at dosages that exceed 4 g/day, and often involve more than one acetaminophen-containing product. Risk is increased with alcohol use, preexisting liver disease, and intake of more than one source of acetaminophen-containing medications. Chronic daily dosing in adults has also resulted in liver damage in some patients.
• Hyperalgesia: Opioid-induced hyperalgesia (OIH) has occurred with short-term and prolonged use of opioid analgesics. Symptoms may include increased levels of pain upon opioid dosage increase, decreased levels of pain upon opioid dosage decrease, or pain from ordinarily nonpainful stimuli; symptoms may be suggestive of OIH if there is no evidence of underlying disease progression, opioid tolerance, opioid withdrawal, or addictive behavior. Consider decreasing the current opioid dose or opioid rotation in patients who experience OIH.
• Hypersensitivity/anaphylactic reactions: Hypersensitivity and anaphylactic reactions have been reported with acetaminophen use; discontinue immediately if symptoms of allergic or hypersensitivity reactions occur.
• Hypotension: May cause severe hypotension (including orthostatic hypotension and syncope); use with caution in patients with hypovolemia, cardiovascular disease (including acute MI), or drugs that may exaggerate hypotensive effects (including phenothiazines or general anesthetics). Monitor for symptoms of hypotension following initiation or dose titration. Avoid use in patients with circulatory shock.
• Phenanthrene hypersensitivity: Use with caution in patients with hypersensitivity reactions to other phenanthrene-derivative opioid agonists (hydrocodone, hydromorphone, levorphanol, oxycodone, oxymorphone).
• Respiratory depression: Fatal respiratory depression may occur. Carbon dioxide retention from opioid-induced respiratory depression can exacerbate the sedating effects of opioids. Patients and caregivers should be educated on how to recognize respiratory depression and the importance of getting emergency assistance immediately (eg, calling 911) in the event of known or suspected overdose.
• Skin reactions: Serious and potentially fatal skin reactions, including acute generalized exanthematous pustulosis, Stevens-Johnson syndrome, and toxic epidermal necrolysis, have occurred rarely with acetaminophen use. Discontinue therapy at the first appearance of skin rash or any other sign of hypersensitivity
Disease-related concerns:
• Abdominal conditions: May obscure diagnosis or clinical course of patients with acute abdominal conditions.
• Adrenocortical insufficiency: Use with caution in patients with adrenocortical insufficiency, including Addison disease. Long-term opioid use may cause secondary hypogonadism, which may lead to mood disorders and osteoporosis (Brennan 2013).
• Biliary tract impairment: Use with caution in patients with biliary tract dysfunction, including acute pancreatitis; opioids may cause constriction of sphincter of Oddi.
• CNS depression/coma: Avoid use in patients with impaired consciousness or coma as these patients are susceptible to intracranial effects of CO2 retention.
• Delirium tremens: Use with caution in patients with delirium tremens.
• G6PD deficiency: Use acetaminophen with caution in patients with known G6PD deficiency.
• Head trauma: Use with extreme caution in patients with head injury, intracranial lesions, or elevated intracranial pressure (ICP); exaggerated elevation of ICP may occur.
• Hepatic impairment: Use with caution in patients with hepatic impairment. Use with caution in patients with alcoholic liver disease; consuming ≥3 alcoholic drinks/day may increase the risk of liver damage.
• Mental health conditions: Use opioids with caution for chronic pain in patients with mental health conditions (eg, depression, anxiety disorders, post-traumatic stress disorder) due to potential increased risk for opioid use disorder and overdose; more frequent monitoring is recommended (CDC [Dowell 2022]).
• Obesity: Use with caution in patients who are morbidly obese.
• Prostatic hyperplasia/urinary stricture: Use with caution in patients with prostatic hyperplasia and/or urinary stricture.
• Psychosis: Use with caution in patients with toxic psychosis.
• Renal impairment: Use with caution in patients with renal impairment.
• Respiratory disease: Use with caution and monitor for respiratory depression in patients with significant chronic obstructive pulmonary disease or cor pulmonale, and those with a substantially decreased respiratory reserve, hypoxia, hypercapnia, or preexisting respiratory depression, particularly when initiating and titrating therapy; critical respiratory depression may occur, even at therapeutic dosages. Consider the use of alternative nonopioid analgesics in these patients.
• Seizure disorder: Use with caution in patients with a history of seizure disorders; may cause or exacerbate seizures.
• Sleep-related disorders: Use with caution in patients with sleep-related disorders, including sleep apnea, due to increased risk for respiratory and central nervous system depression. Monitor carefully and titrate dosage cautiously in patients with mild sleep-disordered breathing. Avoid opioids in patients with moderate to severe sleep-disordered breathing (CDC [Dowell 2022]).
• Thyroid dysfunction: Use with caution in patients with thyroid dysfunction.
Concurrent drug therapy issues:
• Benzodiazepines and other CNS depressants: Concomitant use may result in respiratory depression and sedation, which may be fatal. Consider prescribing naloxone or nalmefene for emergency treatment of opioid overdose in patients taking benzodiazepines or other CNS depressants concomitantly with opioids.
Special populations:
• CYP2D6 "poor metabolizers": Poor metabolizers have decreased metabolism of codeine to its active metabolite, which may diminish analgesia; avoid the use of codeine and consider alternatives that are not metabolized by CYP2D6 (CPIC [Crews 2021]).
• CYP2D6 “ultrarapid metabolizers”: Ultrarapid metabolizers have increased metabolism of codeine to its active metabolite, which may increase the risk of serious adverse effects; avoid the use of codeine and consider alternatives that are not metabolized by CYP2D6 (CPIC [Crews 2021]). The prevalence of this phenotype is estimated to be 1% to 10% for White (European and North American) patients; 3% to 4% for Black patients; 1% to 2% for Chinese, Japanese, and Korean patients; and >10% in certain ethnic groups such as Oceanian, Northern African, Middle Eastern, Ashkenazi Jew, and Puerto Rican patients.
• Cachectic or debilitated patients: Use with caution in cachectic or debilitated patients; there is a greater potential for critical respiratory depression, even at therapeutic dosages. Consider the use of alternative nonopioid analgesics in these patients.
• Older adult: Use opioids with caution in older adults; may be more sensitive to adverse effects. Clearance may also be reduced in older adults (with or without renal impairment) resulting in a narrow therapeutic window and increased adverse effects. Monitor closely for adverse effects associated with opioid therapy (eg, respiratory and CNS depression, falls, cognitive impairment, constipation) (CDC [Dowell 2022]). Consider the use of alternative nonopioid analgesics in these patients when possible.
• Neonates: Neonatal withdrawal syndrome: Signs and symptoms include irritability, hyperactivity and abnormal sleep pattern, high pitched cry, tremor, vomiting, diarrhea, and failure to gain weight. Onset, duration, and severity depend on the drug used, duration of use, maternal dose, and rate of drug elimination by the newborn.
• Pediatric: Life-threatening respiratory depression and death have occurred in children who received codeine. Most of the reported cases occurred following tonsillectomy and/or adenoidectomy, and many of the children had evidence of being ultrarapid metabolizers of codeine due to a CYP2D6 polymorphism. Acetaminophen/codeine is contraindicated in pediatric patients <12 years of age and pediatric patients <18 years of age following tonsillectomy and/or adenoidectomy. Avoid the use of acetaminophen/codeine in pediatric patients 12 to 18 years of age who have other risk factors that may increase their sensitivity to the respiratory depressant effects of codeine. Risk factors include conditions associated with hypoventilation, such as postoperative status, obstructive sleep apnea, obesity, severe pulmonary disease, neuromuscular disease, and concomitant use of other medications that cause respiratory depression. Deaths have also occurred in breastfeeding infants after being exposed to high concentrations of morphine because the mothers were ultrarapid metabolizers.
Dosage form specific issues:
• Benzyl alcohol and derivatives: Some dosage forms may contain sodium benzoate/benzoic acid; benzoic acid (benzoate) is a metabolite of benzyl alcohol; large amounts of benzyl alcohol (≥99 mg/kg/day) have been associated with a potentially fatal toxicity (“gasping syndrome”) in neonates; the “gasping syndrome” consists of metabolic acidosis, respiratory distress, gasping respirations, CNS dysfunction (including convulsions, intracranial hemorrhage), hypotension, and cardiovascular collapse (AAP ["Inactive" 1997]; CDC 1982); some data suggests that benzoate displaces bilirubin from protein binding sites (Ahlfors 2001); avoid or use dosage forms containing benzyl alcohol derivative with caution in neonates. See manufacturer's labeling.
• Ethanol: Oral solution contains 4% v/v ethyl alcohol.
• Metabisulfite: Some products may contain metabisulfite, which may cause allergic reactions.
• Propylene glycol: Some dosage forms may contain propylene glycol; large amounts are potentially toxic and have been associated hyperosmolality, lactic acidosis, seizures and respiratory depression; use caution (AAP ["Inactive" 1997]; Zar 2007).
Other warnings/precautions:
• Abrupt discontinuation/withdrawal: Abrupt discontinuation in patients who are physically dependent on opioids has been associated with serious withdrawal symptoms, uncontrolled pain, attempts to find other opioids (including illicit), and suicide. Use a collaborative, patient-specific taper schedule that minimizes the risk of withdrawal, considering factors such as current opioid dose, duration of use, type of pain, and physical and psychological factors. Monitor pain control, withdrawal symptoms, mood changes, suicidal ideation, and for use of other substances; provide care as needed. Concurrent use of mixed agonist/antagonist (eg, pentazocine, nalbuphine, butorphanol) or partial agonist (eg, buprenorphine) analgesics may also precipitate withdrawal symptoms and/or reduced analgesic efficacy in patients following prolonged therapy with mu opioid agonists.
• Abuse/misuse/diversion: Use with caution in patients with a history of substance use disorder; potential for drug dependency exists. Other factors associated with increased risk for misuse include concomitant depression or other mental health conditions, higher opioid dosages, or taking other CNS depressants. Consider offering naloxone or nalmefene prescriptions in patients with an increased risk for overdose, such as history of overdose or substance use disorder, higher opioid dosages (≥50 morphine milligram equivalents [MME]/day orally), concomitant benzodiazepine use, and patients at risk for returning to a high dose after losing tolerance (CDC [Dowell 2022]).
• Appropriate use: Outpatient setting: Opioids should not be used as first-line therapy for acute (<1 month duration), subacute (1 to 3 month duration), or chronic pain (>3 month duration [outside of end-of-life or palliative care, active cancer treatment, sickle cell disease, or medication-based opioid use disorder treatment]). Preferred management includes nonpharmacologic therapy and nonopioid therapy (eg, nonsteroidal anti-inflammatory drugs, acetaminophen, certain antiseizure medications and antidepressants) as appropriate for the specific condition. If opioid therapy is initiated, it should be combined with nonpharmacologic and nonopioid therapy, as appropriate. Prior to initiation, known risks and realistic benefits of opioid therapy should be discussed with the patient. Therapy should be initiated at the lowest effective dosage using IR opioids (instead of ER/long-acting opioids). For the treatment of acute pain, therapy should only be given for the expected duration of pain severe enough to require opioids and prescribed as needed (not scheduled). For the treatment of subacute and chronic pain, realistic treatment goals for pain/function should be established, including consideration for discontinuation if benefits do not outweigh risks. Therapy should be continued only if clinically meaningful improvement in pain/function outweighs risks. Risk to patients increases with higher opioid dosages. Dosages ≥50 MME/day are likely to not have increased benefit to pain relief or function relative to overall risk to patients; before increasing dosage to ≥50 MME/day, readdress pain and reassess evidence of individual benefits and risks (CDC [Dowell 2022]).
• Dosage limit: Limit acetaminophen dose from all sources (prescription, OTC, combination products) to <4 g/day in adults. Do not use acetaminophen/codeine concomitantly with other acetaminophen-containing products.
• Naloxone/Nalmefene access: Discuss the availability of naloxone or nalmefene with all patients who are prescribed opioid analgesics, as well as their caregivers, and consider prescribing it to patients who are at increased risk of opioid overdose. These include patients who are also taking benzodiazepines or other CNS depressants, have an opioid use disorder (OUD) (current or history of), or have experienced opioid-induced respiratory depression/opioid overdose. Additionally, health care providers should consider prescribing naloxone or nalmefene to patients prescribed medications to treat OUD; patients at risk of opioid overdose even if they are not taking an opioid analgesic or medication to treat OUD; and patients taking opioids, including methadone or buprenorphine for OUD, if they have household members, including children, or other close contacts at risk for accidental ingestion or opioid overdose. Inform patients and caregivers on options for obtaining naloxone or nalmefene (eg, by prescription, directly from a pharmacist, a community-based program) as permitted by state dispensing and prescribing guidelines. Educate patients and caregivers on how to recognize respiratory depression, proper administration of naloxone or nalmefene, and getting emergency help.
• Optimal regimen: An opioid-containing analgesic regimen should be tailored to each patient's needs and based upon the type of pain being treated (acute vs chronic), the route of administration, degree of tolerance for opioids (naive vs chronic user), age, weight, and medical condition. The optimal analgesic dose varies widely among patients; doses should be titrated to pain relief/prevention.
• Risk Evaluation and Mitigation Strategy (REMS): To ensure that the benefits of opioid analgesics outweigh the risks of substance use disorder, abuse, and misuse, the FDA has required a REMS for these products. Under the requirements of the REMS, drug companies with approved opioid analgesic products must make REMS-compliant education programs available to health care providers.
• Surgery: Opioids decrease bowel motility; monitor for decreased bowel motility in postoperative patients receiving opioids. Use with caution in the perioperative setting; individualize treatment when transitioning from parenteral to oral analgesics.
Within US labeling, use is contraindicated in pediatric patients <12 years of age and for postoperative management in pediatric patients 12 to 18 years of age who have undergone tonsillectomy and/or adenoidectomy. Avoid codeine use in all pediatric patient populations in which it is contraindicated and in pediatric patients 12 to 18 years of age who have other risk factors that increase risk for respiratory depression associated with codeine (eg, conditions associated with hypoventilation like postoperative status, obstructive sleep apnea, obesity, severe pulmonary disease, neuromuscular disease, use of other medications known to depress respiratory drive); in rare cases in which a codeine-containing product is the only option, consider genotype testing prior to use; use extra precaution; monitor closely for adverse effects. Prior to 2017, acetaminophen/codeine was approved for use in children as young as 3 years of age. Codeine has also been removed from the WHO List of Essential Medications in Children since 2011. Codeine has been associated with reports of life-threatening or fatal respiratory depression in children and adolescents; a review of FDA adverse events data and the literature includes reports of at least 21 deaths in infants or children (1965-2015). Multifactorial causes for the respiratory depression have been identified; of primary concern are unrecognized ultrarapid metabolizers of CYP2D6 who may have extensive conversion of codeine (prodrug) to morphine and thus increased opioid-mediated effects (ie, respiratory depression). Other oral opioid and nonopioid analgesics are alternate options depending upon severity of pain and other patient specific factors (eg, age, route of administration, etc); however, each also has unique therapeutic challenges and concerns; refer to individual monographs for detailed information (AAP [Tobias 2016]; Dancel 2017; Gammal 2016; Goldschneider 2017; Poonai 2015).
Hepatoxicity has been reported in patients using acetaminophen. In pediatric patients, this is most commonly associated with supratherapeutic dosing, more frequent administration than recommended, and use of multiple acetaminophen-containing products; however, hepatotoxicity has been rarely reported with recommended dosages (AAP [Sullivan 2011]; Heard 2014). All sources of acetaminophen (eg, prescription, OTC, combination) should be considered when evaluating a patient's maximum daily dose. To lower the risk for hepatotoxicity, the maximum daily acetaminophen dose should be limited to ≤75 mg/kg/day (maximum of 5 daily doses), not to exceed 4,000 mg/day (AAP [Sullivan 2011]; Heard 2014; Krenzelok 2012; Lavonas 2010). Acetaminophen avoidance or a lower total daily dose (2,000 to 3,000 mg/day) has been suggested for adults with increased risk for acetaminophen hepatotoxicity (eg, malnutrition, certain liver diseases, use of drugs that interact with acetaminophen metabolism); similar data are unavailable in pediatric patients (Hayward 2016; Larson 2007; Worriax 2007).
Some dosage forms may contain propylene glycol; in neonates, large amounts of propylene glycol delivered orally, intravenously (eg, >3,000 mg/day), or topically have been associated with potentially fatal toxicities which can include metabolic acidosis, seizures, renal failure, and CNS depression; toxicities have also been reported in children and adults including hyperosmolality, lactic acidosis, seizures, and respiratory depression; use caution (AAP 1997; Shehab 2009).
Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product
Solution, Oral:
Generic: Acetaminophen 120 mg and codeine phosphate 12 mg per 5 mL (5 mL, 12.5 mL, 118 mL [DSC], 473 mL)
Tablet, Oral:
Generic: Acetaminophen 300 mg and codeine phosphate 15 mg, Acetaminophen 300 mg and codeine phosphate 30 mg, Acetaminophen 300 mg and codeine phosphate 60 mg
Yes
Solution (Acetaminophen-Codeine Oral)
120-12 mg/5 mL (per mL): $1.95
Tablets (Acetaminophen-Codeine Oral)
300-15 mg (per each): $0.22 - $0.77
300-30 mg (per each): $0.23 - $1.43
300-60 mg (per each): $0.35 - $1.09
Disclaimer: A representative AWP (Average Wholesale Price) price or price range is provided as reference price only. A range is provided when more than one manufacturer's AWP price is available and uses the low and high price reported by the manufacturers to determine the range. The pricing data should be used for benchmarking purposes only, and as such should not be used alone to set or adjudicate any prices for reimbursement or purchasing functions or considered to be an exact price for a single product and/or manufacturer. Medi-Span expressly disclaims all warranties of any kind or nature, whether express or implied, and assumes no liability with respect to accuracy of price or price range data published in its solutions. In no event shall Medi-Span be liable for special, indirect, incidental, or consequential damages arising from use of price or price range data. Pricing data is updated monthly.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Elixir, Oral:
Generic: Acetaminophen 160 mg and codeine 8 mg per 5 mL (100 mL, 500 mL)
Tablet, Oral:
Triatec-30: Acetaminophen 300 mg and codeine phosphate 30 mg [contains fd&c yellow #6(sunset yellow)alumin lake]
Generic: Acetaminophen 300 mg and codeine phosphate 30 mg, Acetaminophen 300 mg and codeine phosphate 60 mg
Liquid products: C-V; Tablet: C-III
Oral: Administer with an accurate measuring device (calibrated oral syringe or measuring cup); do not use a household teaspoon or tablespoon to measure dose (overdosage may occur).
Oral solution: Administer with an accurate measuring device (calibrated oral syringe or measuring cup); do not use a household teaspoon or tablespoon to measure dose (overdosage may occur).
Store at 20°C to 25°C (68°F to 77°F); protect from light.
Relief of mild to moderate pain (FDA approved in adults).
Procet-30 may be confused with Percocet
Tylenol may be confused with atenolol, timolol, Tylox
The Institute for Safe Medication Practices (ISMP) includes this medication among its list of drug classes (opioids, all formulations and routes of administration; pediatric liquid medications requiring measurement) which have a heightened risk of causing significant patient harm when used in error (High-Alert Medications in Acute Care, Community/Ambulatory Care, and Long-Term Care Settings).
KIDs List: Codeine, when used in pediatric patients <18 years of age, is identified on the Key Potentially Inappropriate Drugs in Pediatrics (KIDs) list and should be avoided due to risk of respiratory depression and death unless pharmacogenetic testing completed (strong recommendation; high quality of evidence) (PPA [Meyers 2020]).
Duplicate therapy issues: This product contains acetaminophen, which may be a component of other combination products. Do not exceed the maximum recommended daily dose of acetaminophen.
T3 is an error-prone abbreviation (mistaken as liothyronine)
Codex: Brand name for acetaminophen/codeine [Brazil], but also the brand name for saccharomyces boulardii [Italy]
Codex [Brazil] may be confused with Cedax brand name for ceftibuten [US and multiple international markets]
Refer to individual components.
Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the drug interactions program by clicking on the “Launch drug interactions program” link above.
Note: Interacting drugs may not be individually listed below if they are part of a group interaction (eg, individual drugs within “CYP3A4 Inducers [Strong]” are NOT listed). For a complete list of drug interactions by individual drug name and detailed management recommendations, use the drug interactions program
Agents with Clinically Relevant Anticholinergic Effects: May increase adverse/toxic effects of Opioid Agonists. Specifically, the risk for constipation and urinary retention may be increased with this combination. Risk C: Monitor
Ajmaline: May increase serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Risk C: Monitor
Alizapride: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Alvimopan: Opioid Agonists may increase adverse/toxic effects of Alvimopan. This is most notable for patients receiving long-term (i.e., more than 7 days) opiates prior to alvimopan initiation. Management: Alvimopan is contraindicated in patients receiving therapeutic doses of opioids for more than 7 consecutive days immediately prior to alvimopan initiation. Risk D: Consider Therapy Modification
Amisulpride (Oral): May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Amphetamines: May increase analgesic effects of Opioid Agonists. Risk C: Monitor
Artemether and Lumefantrine: May increase serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Risk C: Monitor
Articaine: May increase CNS depressant effects of CNS Depressants. Management: Consider reducing the dose of articaine if possible when used in patients who are also receiving CNS depressants. Monitor for excessive CNS depressant effects with any combined use. Risk D: Consider Therapy Modification
Atazanavir: May increase serum concentration of UGT1A1 Substrates. Management: Do not use UGT1A1 substrates for which small increases in exposure can cause serious adverse effects together with atazanavir, and use caution with any UGT1A1 substrate, even when small changes in exposure are less likely to cause serious adverse effects. Risk D: Consider Therapy Modification
Azelastine (Nasal): May increase CNS depressant effects of CNS Depressants. Risk X: Avoid
Belumosudil: May increase serum concentration of UGT1A1 Substrates. Management: Avoid coadministration of belumosudil with substrates of UGT1A1 for which minimal concentration increases can cause serious adverse effects. If coadministration is required, dose reductions of the UGT1A1 substrate may be required. Risk D: Consider Therapy Modification
Benperidol: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Blonanserin: CNS Depressants may increase CNS depressant effects of Blonanserin. Management: Use caution if coadministering blonanserin and CNS depressants; dose reduction of the other CNS depressant may be required. Strong CNS depressants should not be coadministered with blonanserin. Risk D: Consider Therapy Modification
Brimonidine (Topical): May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Bromopride: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Bromperidol: May increase CNS depressant effects of CNS Depressants. Risk X: Avoid
Buclizine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Buprenorphine: CNS Depressants may increase CNS depressant effects of Buprenorphine. Management: Consider reduced doses of other CNS depressants, and avoiding such drugs in patients at high risk of buprenorphine overuse/self-injection. Initiate buprenorphine at lower doses in patients already receiving CNS depressants. Risk D: Consider Therapy Modification
Buprenorphine: May decrease therapeutic effects of Opioid Agonists. Management: Seek alternatives to buprenorphine in patients receiving pure opioid agonists. If combined in certain pain management situations (eg, surgery), monitor for symptoms of therapeutic failure/high dose requirements or opioid withdrawal symptoms. Risk D: Consider Therapy Modification
BusPIRone: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Busulfan: Acetaminophen may increase serum concentration of Busulfan. Risk C: Monitor
Cannabinoid-Containing Products: CNS Depressants may increase CNS depressant effects of Cannabinoid-Containing Products. Risk C: Monitor
CarBAMazepine: May increase metabolism of Acetaminophen. This may 1) diminish the effect of acetaminophen; and 2) increase the risk of liver damage. Risk C: Monitor
Cetirizine (Systemic): May increase CNS depressant effects of CNS Depressants. Management: Consider avoiding this combination if possible. If required, monitor for excessive sedation or CNS depression, limit the dose and duration of combination therapy, and consider CNS depressant dose reductions. Risk D: Consider Therapy Modification
Chloral Hydrate/Chloral Betaine: CNS Depressants may increase CNS depressant effects of Chloral Hydrate/Chloral Betaine. Management: Consider alternatives to the use of chloral hydrate or chloral betaine and additional CNS depressants. If combined, consider a dose reduction of either agent and monitor closely for enhanced CNS depressive effects. Risk D: Consider Therapy Modification
Chlormethiazole: May increase CNS depressant effects of CNS Depressants. Management: Monitor closely for evidence of excessive CNS depression. The chlormethiazole labeling states that an appropriately reduced dose should be used if such a combination must be used. Risk D: Consider Therapy Modification
Chlorphenesin Carbamate: May increase adverse/toxic effects of CNS Depressants. Risk C: Monitor
CNS Depressants: May increase CNS depressant effects of Opioid Agonists. Management: Avoid concomitant use of opioid agonists and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Risk D: Consider Therapy Modification
CYP2D6 Inhibitors (Moderate): May decrease therapeutic effects of Codeine. These CYP2D6 inhibitors may prevent the metabolic conversion of codeine to its active metabolite morphine. Risk C: Monitor
CYP2D6 Inhibitors (Strong): May decrease therapeutic effects of Codeine. These CYP2D6 inhibitors may prevent the metabolic conversion of codeine to its active metabolite morphine. Risk C: Monitor
CYP3A4 Inducers (Moderate): May decrease active metabolite exposure of Codeine. Risk C: Monitor
CYP3A4 Inducers (Strong): May decrease active metabolite exposure of Codeine. Risk C: Monitor
CYP3A4 Inhibitors (Moderate): May increase active metabolite exposure of Codeine. Risk C: Monitor
CYP3A4 Inhibitors (Strong): May increase active metabolite exposure of Codeine. Risk C: Monitor
Dapsone (Topical): May increase adverse/toxic effects of Methemoglobinemia Associated Agents. Risk C: Monitor
Daridorexant: May increase CNS depressant effects of CNS Depressants. Management: Dose reduction of daridorexant and/or any other CNS depressant may be necessary. Use of daridorexant with alcohol is not recommended, and the use of daridorexant with any other drug to treat insomnia is not recommended. Risk D: Consider Therapy Modification
Dasatinib: Acetaminophen may increase hepatotoxic effects of Dasatinib. Dasatinib may increase serum concentration of Acetaminophen. Management: Avoid coadministration of acetaminophen and dasatinib if possible. If coadministration is unavoidable, monitor for signs/symptoms of hepatotoxicity, particularly in patients with greater acetaminophen exposure. Risk D: Consider Therapy Modification
Desmopressin: Opioid Agonists may increase hyponatremic effects of Desmopressin. Risk C: Monitor
DexmedeTOMIDine: CNS Depressants may increase CNS depressant effects of DexmedeTOMIDine. Management: Monitor for increased CNS depression during coadministration of dexmedetomidine and CNS depressants, and consider dose reductions of either agent to avoid excessive CNS depression. Risk D: Consider Therapy Modification
Difelikefalin: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Dihydralazine: CNS Depressants may increase hypotensive effects of Dihydralazine. Risk C: Monitor
Dimethindene (Topical): May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Diuretics: Opioid Agonists may increase adverse/toxic effects of Diuretics. Opioid Agonists may decrease therapeutic effects of Diuretics. Risk C: Monitor
Dothiepin: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
DroPERidol: May increase CNS depressant effects of CNS Depressants. Management: Consider dose reductions of droperidol or of other CNS agents (eg, opioids, barbiturates) with concomitant use. Risk D: Consider Therapy Modification
Eluxadoline: Opioid Agonists may increase constipating effects of Eluxadoline. Risk X: Avoid
Emedastine (Systemic): May increase CNS depressant effects of CNS Depressants. Management: Consider avoiding this combination if possible. If required, monitor for excessive sedation or CNS depression, limit the dose and duration of combination therapy, and consider CNS depressant dose reductions. Risk C: Monitor
Entacapone: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Flucloxacillin: May increase adverse/toxic effects of Acetaminophen. Specifically, the risk for high anion gap metabolic acidosis may be increased. Risk C: Monitor
Flunarizine: CNS Depressants may increase CNS depressant effects of Flunarizine. Risk X: Avoid
Flunitrazepam: CNS Depressants may increase CNS depressant effects of Flunitrazepam. Management: Reduce the dose of CNS depressants when combined with flunitrazepam and monitor patients for evidence of CNS depression (eg, sedation, respiratory depression). Use non-CNS depressant alternatives when available. Risk D: Consider Therapy Modification
Fosphenytoin-Phenytoin: May decrease serum concentration of Acetaminophen. Specifically, serum concentrations of acetaminophen may be decreased (leading to decreased efficacy), but the formation of the toxic N-acetyl-p-benzoquinone imine (NAPQI) metabolite may be increased (leading to increased hepatotoxicity). Risk C: Monitor
Gastrointestinal Agents (Prokinetic): Opioid Agonists may decrease therapeutic effects of Gastrointestinal Agents (Prokinetic). Risk C: Monitor
Grapefruit Juice: May increase serum concentration of Codeine. Risk C: Monitor
HydrOXYzine: May increase CNS depressant effects of CNS Depressants. Management: Consider a decrease in the CNS depressant dose, as appropriate, when used together with hydroxyzine. Increase monitoring of signs/symptoms of CNS depression in any patient receiving hydroxyzine together with another CNS depressant. Risk D: Consider Therapy Modification
Imatinib: Acetaminophen may increase hepatotoxic effects of Imatinib. Risk C: Monitor
Immune Checkpoint Inhibitors (Anti-PD-1, -PD-L1, and -CTLA4 Therapies): Acetaminophen may decrease therapeutic effects of Immune Checkpoint Inhibitors (Anti-PD-1, -PD-L1, and -CTLA4 Therapies). Risk C: Monitor
Isoniazid: May increase hepatotoxic effects of Acetaminophen. Isoniazid may increase metabolism of Acetaminophen. Specifically, formation of the hepatotoxic NAPQI metabolite may be increased. Risk C: Monitor
Ixabepilone: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Kava Kava: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Ketotifen (Systemic): May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Kratom: May increase CNS depressant effects of CNS Depressants. Risk X: Avoid
LamoTRIgine: Acetaminophen may decrease serum concentration of LamoTRIgine. Risk C: Monitor
Lemborexant: May increase CNS depressant effects of CNS Depressants. Management: Dosage adjustments of lemborexant and of concomitant CNS depressants may be necessary when administered together because of potentially additive CNS depressant effects. Close monitoring for CNS depressant effects is necessary. Risk D: Consider Therapy Modification
Levocetirizine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Lisuride: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Local Anesthetics: Methemoglobinemia Associated Agents may increase adverse/toxic effects of Local Anesthetics. Specifically, the risk for methemoglobinemia may be increased. Risk C: Monitor
Lofexidine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Lorlatinib: May decrease serum concentration of Acetaminophen. Risk C: Monitor
Loxapine: CNS Depressants may increase CNS depressant effects of Loxapine. Management: Consider reducing the dose of CNS depressants administered concomitantly with loxapine due to an increased risk of respiratory depression, sedation, hypotension, and syncope. Risk D: Consider Therapy Modification
Magnesium Sulfate: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Mavorixafor: May increase serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Risk X: Avoid
Mequitazine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Metergoline: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Methotrimeprazine: CNS Depressants may increase CNS depressant effects of Methotrimeprazine. Methotrimeprazine may increase CNS depressant effects of CNS Depressants. Management: Reduce the usual dose of CNS depressants by 50% if starting methotrimeprazine until the dose of methotrimeprazine is stable. Monitor patient closely for evidence of CNS depression. Risk D: Consider Therapy Modification
Metoclopramide: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
MetyraPONE: May increase serum concentration of Acetaminophen. More importantly, by inhibiting the conjugative metabolism of acetaminophen, metyrapone may shift the metabolism towards the oxidative route that produces a hepatotoxic metabolite. Risk X: Avoid
MetyroSINE: CNS Depressants may increase sedative effects of MetyroSINE. Risk C: Monitor
Minocycline (Systemic): May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Mitapivat: May decrease serum concentration of UGT1A1 Substrates. Risk C: Monitor
Monoamine Oxidase Inhibitors: May increase adverse/toxic effects of Codeine. Risk X: Avoid
Moxonidine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Nabilone: May increase CNS depressant effects of CNS Depressants. Risk X: Avoid
Nalfurafine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Nalfurafine: Opioid Agonists may increase adverse/toxic effects of Nalfurafine. Opioid Agonists may decrease therapeutic effects of Nalfurafine. Risk C: Monitor
Nalmefene: May decrease therapeutic effects of Opioid Agonists. Management: Avoid the concomitant use of oral nalmefene and opioid agonists. Discontinue oral nalmefene 1 week prior to any anticipated use of opioid agonists. If combined, larger doses of opioid agonists will likely be required. Risk D: Consider Therapy Modification
Naltrexone: May decrease therapeutic effects of Opioid Agonists. Management: Seek therapeutic alternatives to opioids. See full drug interaction monograph for detailed recommendations. Risk X: Avoid
Nefazodone: Opioid Agonists (metabolized by CYP3A4 and CYP2D6) may increase serotonergic effects of Nefazodone. This could result in serotonin syndrome. Nefazodone may increase serum concentration of Opioid Agonists (metabolized by CYP3A4 and CYP2D6). Management: Monitor for increased opioid effects, including fatal respiratory depression, when these agents are combined and consider opioid dose reductions until stable drug effects are achieved. Additionally, monitor for serotonin syndrome/serotonin toxicity. Risk C: Monitor
Nitric Oxide: May increase adverse/toxic effects of Methemoglobinemia Associated Agents. Combinations of these agents may increase the likelihood of significant methemoglobinemia. Risk C: Monitor
Noscapine: CNS Depressants may increase adverse/toxic effects of Noscapine. Risk X: Avoid
Olopatadine (Nasal): May increase CNS depressant effects of CNS Depressants. Risk X: Avoid
Opicapone: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Opioid Agonists: CNS Depressants may increase CNS depressant effects of Opioid Agonists. Management: Avoid concomitant use of opioid agonists and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Risk D: Consider Therapy Modification
Opioids (Mixed Agonist / Antagonist): May decrease analgesic effects of Opioid Agonists. Management: Seek alternatives to mixed agonist/antagonist opioids in patients receiving pure opioid agonists, and monitor for symptoms of therapeutic failure/high dose requirements (or withdrawal in opioid-dependent patients) if patients receive these combinations. Risk X: Avoid
Opipramol: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Orphenadrine: CNS Depressants may increase CNS depressant effects of Orphenadrine. Risk X: Avoid
Oxomemazine: May increase CNS depressant effects of CNS Depressants. Risk X: Avoid
Oxybate Salt Products: CNS Depressants may increase CNS depressant effects of Oxybate Salt Products. Management: Consider alternatives to this combination when possible. If combined, dose reduction or discontinuation of one or more CNS depressants (including the oxybate salt product) should be considered. Interrupt oxybate salt treatment during short-term opioid use Risk D: Consider Therapy Modification
OxyCODONE: CNS Depressants may increase CNS depressant effects of OxyCODONE. Management: Avoid concomitant use of oxycodone and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug. Risk D: Consider Therapy Modification
Paraldehyde: CNS Depressants may increase CNS depressant effects of Paraldehyde. Risk X: Avoid
Peginterferon Alfa-2b: May decrease serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Peginterferon Alfa-2b may increase serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Risk C: Monitor
Pegvisomant: Opioid Agonists may decrease therapeutic effects of Pegvisomant. Risk C: Monitor
Periciazine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
PHENobarbital: May increase CNS depressant effects of Codeine. PHENobarbital may decrease serum concentration of Codeine. Management: Avoid use of codeine and phenobarbital when possible. Monitor for respiratory depression/sedation. Because phenobarbital is also a moderate CYP3A4 inducer, monitor for decreased codeine efficacy and withdrawal if combined. Risk D: Consider Therapy Modification
Phenylephrine (Systemic): Acetaminophen may increase serum concentration of Phenylephrine (Systemic). Risk C: Monitor
Pipamperone: May increase adverse/toxic effects of CNS Depressants. Risk C: Monitor
Piribedil: CNS Depressants may increase CNS depressant effects of Piribedil. Risk C: Monitor
Pramipexole: CNS Depressants may increase sedative effects of Pramipexole. Risk C: Monitor
Prilocaine: Methemoglobinemia Associated Agents may increase adverse/toxic effects of Prilocaine. Combinations of these agents may increase the likelihood of significant methemoglobinemia. Management: Monitor for signs of methemoglobinemia when prilocaine is used in combination with other agents associated with development of methemoglobinemia. Avoid use of these agents with prilocaine/lidocaine cream in infants less than 12 months of age. Risk C: Monitor
Primaquine: Methemoglobinemia Associated Agents may increase adverse/toxic effects of Primaquine. Specifically, the risk for methemoglobinemia may be increased. Management: Avoid concomitant use of primaquine and other drugs that are associated with methemoglobinemia when possible. If combined, monitor methemoglobin levels closely. Risk D: Consider Therapy Modification
Primidone: May increase CNS depressant effects of Codeine. Primidone may decrease serum concentration of Codeine. Management: Avoid use of codeine and primidone when possible. Monitor for respiratory depression/sedation. Because primidone is also a strong CYP3A4 inducer, monitor for decreased codeine efficacy and withdrawal if combined. Risk D: Consider Therapy Modification
Probenecid: May increase serum concentration of Acetaminophen. Probenecid may also limit the formation of at least one major non-toxic metabolite, possibly increasing the potential for formation of the toxic NAPQI metabolite. Management: Consider limiting acetaminophen use in combination with probenecid. Probenecid may reduce clearance of acetaminophen to one of its non-toxic metabolities, increasing the risk for acetaminophen toxicity, even a lower doses. Risk D: Consider Therapy Modification
Procarbazine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Ramosetron: Opioid Agonists may increase constipating effects of Ramosetron. Risk C: Monitor
RifAMPin: May increase hepatotoxic effects of Acetaminophen. RifAMPin may decrease serum concentration of Acetaminophen. Risk C: Monitor
Rilmenidine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Ropeginterferon Alfa-2b: CNS Depressants may increase adverse/toxic effects of Ropeginterferon Alfa-2b. Specifically, the risk of neuropsychiatric adverse effects may be increased. Management: Avoid coadministration of ropeginterferon alfa-2b and other CNS depressants. If this combination cannot be avoided, monitor patients for neuropsychiatric adverse effects (eg, depression, suicidal ideation, aggression, mania). Risk D: Consider Therapy Modification
ROPINIRole: CNS Depressants may increase sedative effects of ROPINIRole. Risk C: Monitor
Rotigotine: CNS Depressants may increase sedative effects of Rotigotine. Risk C: Monitor
Samidorphan: May decrease therapeutic effects of Opioid Agonists. Risk X: Avoid
Selective Serotonin Reuptake Inhibitors (Strong CYP2D6 Inhibitors): Opioid Agonists (metabolized by CYP3A4 and CYP2D6) may increase serotonergic effects of Selective Serotonin Reuptake Inhibitors (Strong CYP2D6 Inhibitors). This could result in serotonin syndrome. Selective Serotonin Reuptake Inhibitors (Strong CYP2D6 Inhibitors) may decrease therapeutic effects of Opioid Agonists (metabolized by CYP3A4 and CYP2D6). Management: Monitor for decreased therapeutic response (eg, analgesia) and opioid withdrawal when coadministered with SSRIs that strongly inhibit CYP2D6. Additionally, monitor for serotonin syndrome/serotonin toxicity if these drugs are combined. Risk C: Monitor
Serotonergic Agents (High Risk): Opioid Agonists (metabolized by CYP3A4 and CYP2D6) may increase serotonergic effects of Serotonergic Agents (High Risk). This could result in serotonin syndrome. Management: Monitor for signs and symptoms of serotonin syndrome/serotonin toxicity (eg, hyperreflexia, clonus, hyperthermia, diaphoresis, tremor, autonomic instability, mental status changes) when these agents are combined. Risk C: Monitor
Sincalide: Drugs that Affect Gallbladder Function may decrease therapeutic effects of Sincalide. Management: Consider discontinuing drugs that may affect gallbladder motility prior to the use of sincalide to stimulate gallbladder contraction. Risk D: Consider Therapy Modification
Sodium Nitrite: Methemoglobinemia Associated Agents may increase adverse/toxic effects of Sodium Nitrite. Combinations of these agents may increase the likelihood of significant methemoglobinemia. Risk C: Monitor
Somatostatin Analogs: May decrease active metabolite exposure of Codeine. Specifically, the concentrations of the active metabolite morphine may be reduced. Risk C: Monitor
SORAfenib: Acetaminophen may increase hepatotoxic effects of SORAfenib. SORAfenib may increase serum concentration of Acetaminophen. Management: Avoid coadministration of acetaminophen and sorafenib if possible. If coadministration is unavoidable, monitor for signs/symptoms of hepatotoxicity, particularly in patients with greater acetaminophen exposure. Risk D: Consider Therapy Modification
Succinylcholine: May increase bradycardic effects of Opioid Agonists. Risk C: Monitor
Suvorexant: CNS Depressants may increase CNS depressant effects of Suvorexant. Management: Dose reduction of suvorexant and/or any other CNS depressant may be necessary. Use of suvorexant with alcohol is not recommended, and the use of suvorexant with any other drug to treat insomnia is not recommended. Risk D: Consider Therapy Modification
Thalidomide: CNS Depressants may increase CNS depressant effects of Thalidomide. Risk X: Avoid
Tilidine: May increase therapeutic effects of Opioid Agonists. Risk X: Avoid
Vaccines: Acetaminophen may decrease therapeutic effects of Vaccines. Management: Consider avoiding routine prophylactic use of acetaminophen before or during vaccine administration when possible. Acetaminophen is still recommended to treat fevers and/or pain that occurs after vaccination. Risk D: Consider Therapy Modification
Valerian: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Vitamin K Antagonists: Acetaminophen may increase anticoagulant effects of Vitamin K Antagonists. This appears most likely with daily acetaminophen doses exceeding 1.3 or 2 g/day for multiple consecutive days. Risk C: Monitor
Zolpidem: CNS Depressants may increase CNS depressant effects of Zolpidem. Management: Reduce the Intermezzo brand sublingual zolpidem adult dose to 1.75 mg for men who are also receiving other CNS depressants. No such dose change is recommended for women. Avoid use with other CNS depressants at bedtime; avoid use with alcohol. Risk D: Consider Therapy Modification
Zuranolone: May increase CNS depressant effects of CNS Depressants. Management: Consider alternatives to the use of zuranolone with other CNS depressants or alcohol. If combined, consider a zuranolone dose reduction and monitor patients closely for increased CNS depressant effects. Risk D: Consider Therapy Modification
Long-term opioid use may cause secondary hypogonadism, which may lead to sexual dysfunction and infertility (Brennan 2013).
[US Boxed Warning]: If opioid use is required for an extended period of time in a pregnant woman, advise the patient of the risk of neonatal opioid withdrawal syndrome (NOWS), which may be life-threatening if not recognized and treated. Ensure that management by neonatology experts will be available at delivery .
Refer to individual monographs for additional information.
Pain relief, respiratory rate, mental status, blood pressure, bowel function; signs of misuse, abuse, and substance use disorder.
Acetaminophen: Although not fully elucidated, the analgesic effects are believed to be due to activation of descending serotonergic inhibitory pathways in the CNS. Interactions with other nociceptive systems may be involved as well (Smith 2009). Antipyresis is produced from inhibition of the hypothalamic heat-regulating center.
Codeine: Binds to opiate receptors in the CNS, causing inhibition of ascending pain pathways, altering the perception of and response to pain; causes cough suppression by direct central action in the medulla; produces generalized CNS depression.
See individual agents.
