Upper respiratory tract conditions: Oral: Note: Do not exceed recommended dosage. Chlorpheniramine dosing in terms of chlorpheniramine maleate; phenylephrine dosing in terms of phenylephrine hydrochloride:
Liquid: Chlorpheniramine 4 mg and phenylephrine 10 mg per 5 mL: 5 mL every 4 hours (maximum: 30 mL/24 hours).
Tablet: Chlorpheniramine 4 mg and phenylephrine 10 mg: One tablet every 4 to 6 hours (maximum: 6 tablets/24 hours).
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
There are no dosage adjustments provided in the manufacturer's labeling.
There are no dosage adjustments provided in the manufacturer's labeling.
Avoid use (Ref).
(For additional information see "Chlorpheniramine and phenylephrine: Pediatric drug information")
Note: Safety and efficacy for the use of cough and cold products in infants and young children is limited; the AAP warns against the use of these products for respiratory illnesses in infants and young children; the FDA does not recommend OTC use in infants and children <2 years of age due to the risk of serious and life-threatening adverse effects (including death) and recommends to use with caution in pediatric patients ≥2 years of age (Ref).
Upper respiratory symptoms:
Oral Liquid:
Chlorpheniramine 4 mg/phenylephrine 10 mg per 5 mL (eg, Ed A-Hist liquid, Nohist LQ):
Children 6 years to <12 years: 2.5 mL every 4 hours as needed. Maximum daily dose: 15 mL/24 hours.
Children ≥12 years and Adolescents: 5 mL every 4 hours as needed. Maximum daily dose: 30 mL/24 hours.
Tablet:
Chlorpheniramine 4 mg/phenylephrine 10 mg per tablet:
Children 6 years to <12 years: 1/2 tablet every 4 hours as needed. Maximum daily dose: 3 tablets/24 hours.
Children ≥12 years and Adolescents: 1 tablet every 4 to 6 hours as needed. Maximum daily dose: 6 tablets/24 hours.
Dosage adjustment for concomitant therapy: Significant drug interactions exist, requiring dose/frequency adjustment or avoidance. Consult drug interactions database for more information.
There are no dosage adjustments provided in the manufacturer's labeling.
There are no dosage adjustments provided in the manufacturer's labeling.
See individual agents.
OTC labeling: When used for self-medication, do not use with or within 2 weeks of discontinuing monoamine oxidase inhibitor; to sedate a child; longer than 7 days if no improvement in symptoms or accompanied by fever.
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 which require mental alertness (eg, operating machinery or driving).
Disease-related concerns:
• Cardiovascular disease: Use with caution in patients with cardiovascular disease (including hypertension and heart disease).
• Diabetes: Use with caution in patients with diabetes mellitus.
• GI obstruction: Use with caution in patients with GI obstruction.
• Increased intraocular pressure: Use with caution in patients with increased intraocular pressure.
• Prostatic hyperplasia/urinary obstruction: Use with caution in patients with prostatic hyperplasia and/or GU obstruction.
• Respiratory disease: Use with caution in patients with asthma or other chronic breathing disorders.
• Thyroid dysfunction: Use with caution in patients with thyroid dysfunction.
Special populations:
• Older adult: Use with caution in older adults; may be more sensitive to adverse effects.
• Pediatric: Antihistamines may cause excitation in young children.
Dosage form specific issues:
• Propylene glycol: Some dosage forms may contain propylene glycol; large amounts are potentially toxic and have been associated with hyperosmolality, lactic acidosis, seizures, and respiratory depression; use caution (AAP 1997; Zar 2007).
• Tartrazine: Some products may contain tartrazine.
Other warnings/precautions:
• Self-medication (OTC use): When used for self medication (OTC), discontinue use and notify health care provider if new symptoms occur, if symptoms do not improve within 7 days or are accompanied by fever, rash, or persistent headache or if nervousness, dizziness, or sleeplessness occur.
Safety and efficacy for the use of cough and cold products in pediatric patients <4 years of age is limited; the AAP warns against the use of these products for respiratory illnesses in young children. Serious adverse effects including death have been reported. Many of these products contain multiple active ingredients, increasing the risk of accidental overdose when used with other products. The FDA does not recommend OTC uses for these products in pediatric patients <2 years of age and recommends to use with caution in pediatric patients ≥2 years of age. Health care providers are reminded to ask caregivers about the use of OTC cough and cold products in order to avoid exposure to multiple medications containing the same ingredient (AAP 2018; CDC 2007; FDA 2017; FDA 2018).
Some products may contain alcohol; use caution when using on infants and children.
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.
Liquid, Oral:
Ed A-Hist: Chlorpheniramine maleate 4 mg and phenylephrine hydrochloride 10 mg per 5 mL (473 mL) [gluten free, sugar free; contains alcohol, usp, fd&c blue #1 (brilliant blue), propylene glycol, saccharin sodium, sodium benzoate; grape flavor]
NoHist-LQ: Chlorpheniramine maleate 4 mg and phenylephrine hydrochloride 10 mg per 5 mL (473 mL) [alcohol free, sugar free; contains edetate (edta) disodium, methylparaben, propylene glycol, propylparaben, saccharin calcium; bubble-gum flavor]
Tablet, Oral:
Ed A-Hist: Chlorpheniramine maleate 4 mg and phenylephrine hydrochloride 10 mg [scored; contains fd&c blue #2 (indigotine,indigo carmine), fd&c yellow #5 (tartrazine), fd&c yellow #6 (sunset yellow)]
May be product dependent
Liquid (Ed A-Hist Oral)
4-10 mg/5 mL (per mL): $0.06
Tablets (Ed A-Hist Oral)
4-10 mg (per each): $0.26
Tablets (Giltuss Allergy & Sinus Oral)
3.5-10 mg (per each): $0.45
Tablets (Phenagil Oral)
3.5-10 mg (per each): $0.66
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.
Oral: Administer oral liquids with an accurate measuring device; do not use a household teaspoon (overdosage may occur).
Upper respiratory tract conditions: Temporary relief of symptoms (nasal congestion; runny nose; sneezing; itching of the eyes, nose, or throat) associated with the common cold, hay fever (allergic rhinitis), and other upper respiratory tract conditions.
The Institute for Safe Medication Practices (ISMP) includes this medication among its list of drugs (pediatric liquid medications requiring measurement) which have a heightened risk of causing significant patient harm when used in error (High-Alert Medications in Community/Ambulatory Care Settings).
Beers Criteria: Chlorpheniramine, a first-generation antihistamine, is identified in the Beers Criteria as a potentially inappropriate medication to be avoided in patients 65 years and older (independent of diagnosis or condition) due to its potent anticholinergic properties resulting in increased risk of confusion, dry mouth, constipation, and other anticholinergic effects or toxicity; use should also be avoided due to reduced clearance with advanced age and tolerance associated with use as a hypnotic. Exposure to concurrent anticholinergic drugs also increases risk of falls, delirium, and dementia; consider total anticholinergic burden when conducting medication reviews (Beers Criteria [AGS 2023]).
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.
Acetaminophen: May increase serum concentration of Phenylephrine (Systemic). Risk C: Monitor
Acetylcholinesterase Inhibitors: May decrease therapeutic effects of Agents with Clinically Relevant Anticholinergic Effects. Agents with Clinically Relevant Anticholinergic Effects may decrease therapeutic effects of Acetylcholinesterase Inhibitors. Risk C: Monitor
Aclidinium: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk X: Avoid
Acrivastine: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Acrivastine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Ajmaline: May increase serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Risk C: Monitor
Alcohol (Ethyl): CNS Depressants may increase CNS depressant effects of Alcohol (Ethyl). Risk C: Monitor
Alizapride: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Alpha1-Blockers: May decrease vasoconstricting effects of Phenylephrine (Systemic). Risk C: Monitor
Amantadine: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Amezinium: Antihistamines may increase stimulatory effects of Amezinium. Risk C: Monitor
Amisulpride (Oral): May increase CNS depressant effects of CNS Depressants. 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
Atomoxetine: May increase hypertensive effects of Sympathomimetics. Atomoxetine may increase tachycardic effects of Sympathomimetics. Risk C: Monitor
Atropine (Systemic): May increase hypertensive effects of Alpha1-Agonists. Risk C: Monitor
Azelastine (Nasal): May increase CNS depressant effects of CNS Depressants. Risk X: Avoid
Benperidol: Agents with Clinically Relevant Anticholinergic Effects may decrease therapeutic effects of Benperidol. Risk C: Monitor
Benperidol: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Benztropine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Benztropine. Risk C: Monitor
Benzylpenicilloyl Polylysine: Coadministration of Alpha1-Agonists and Benzylpenicilloyl Polylysine may alter diagnostic results. Management: Consider delaying skin testing until alpha1-agonists are no longer required, or use of a histamine skin test as a positive control to assess a patient's ability to mount a wheal and flare response. Risk D: Consider Therapy Modification
Benzylpenicilloyl Polylysine: Coadministration of Antihistamines and Benzylpenicilloyl Polylysine may alter diagnostic results. Management: Suspend systemic H1 antagonists for benzylpenicilloyl-polylysine skin testing and delay testing until systemic antihistaminic effects have dissipated. A histamine skin test may be used to assess persistent antihistaminic effects. Risk D: Consider Therapy Modification
Betahistine: Antihistamines may decrease therapeutic effects of Betahistine. Betahistine may decrease therapeutic effects of Antihistamines. Risk C: Monitor
Biperiden: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Biperiden. 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
Bornaprine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Bornaprine. Risk C: Monitor
Bornaprine: Sympathomimetics may increase anticholinergic effects of Bornaprine. Risk C: Monitor
Botulinum Toxin-Containing Products: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Brexanolone: CNS Depressants may increase CNS depressant effects of Brexanolone. Risk C: Monitor
Brimonidine (Topical): May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Bromocriptine: May increase hypertensive effects of Alpha1-Agonists. Management: Consider alternatives to this combination when possible. If combined, monitor for hypertension and tachycardia, and do not coadminister these agents for more than 10 days. Risk D: Consider Therapy Modification
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: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Buclizine. Risk C: Monitor
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
BusPIRone: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Cannabinoid-Containing Products: Agents with Clinically Relevant Anticholinergic Effects may increase tachycardic effects of Cannabinoid-Containing Products. Risk C: Monitor
Cannabinoid-Containing Products: CNS Depressants may increase CNS depressant effects of Cannabinoid-Containing Products. Risk C: Monitor
Cannabinoid-Containing Products: May increase tachycardic effects of Sympathomimetics. Risk C: Monitor
Certoparin: Antihistamines may increase therapeutic effects of Certoparin. 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
Chloroprocaine (Systemic): May increase hypotensive effects of Phenylephrine (Systemic). Risk C: Monitor
Chlorphenesin Carbamate: May increase adverse/toxic effects of CNS Depressants. Risk C: Monitor
Chlorprothixene: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Chlorprothixene. Risk C: Monitor
Cimetropium: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Cimetropium. Risk X: Avoid
CloZAPine: Agents with Clinically Relevant Anticholinergic Effects may increase constipating effects of CloZAPine. Management: Consider alternatives to this combination whenever possible. If combined, monitor closely for signs and symptoms of gastrointestinal hypomotility and consider prophylactic laxative treatment. Risk D: Consider Therapy Modification
CNS Depressants: May increase adverse/toxic effects of CNS Depressants. Risk C: Monitor
Cocaine (Topical): May increase hypertensive effects of Sympathomimetics. Management: Consider alternatives to use of this combination when possible. Monitor closely for substantially increased blood pressure or heart rate and for any evidence of myocardial ischemia with concurrent use. Risk D: Consider Therapy Modification
Cyclizine: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
CYP2D6 Inhibitors (Strong): May increase serum concentration of Chlorpheniramine. Risk C: Monitor
Dantrolene: May increase CNS depressant effects of CNS Depressants. 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
Darifenacin: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Darifenacin. 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
Dicyclomine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Dicyclomine. Risk C: Monitor
Difelikefalin: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Difenoxin: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Dihydralazine: CNS Depressants may increase hypotensive effects of Dihydralazine. Risk C: Monitor
Dihydralazine: Sympathomimetics may decrease therapeutic effects of Dihydralazine. Risk C: Monitor
Dimethindene (Systemic): Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Dimethindene (Systemic). Risk C: Monitor
Dimethindene (Topical): May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Dothiepin: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Doxofylline: Sympathomimetics may increase adverse/toxic effects of Doxofylline. Risk C: Monitor
Doxylamine: CNS Depressants may increase CNS depressant effects of Doxylamine. Risk C: Monitor
DroNABinol: Agents with Clinically Relevant Anticholinergic Effects may increase tachycardic effects of DroNABinol. Risk X: Avoid
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: Agents with Clinically Relevant Anticholinergic Effects 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
Ergot Derivatives (Vasoconstrictive CYP3A4 Substrates): May increase vasoconstricting effects of Alpha1-Agonists. Risk X: Avoid
Esketamine (Injection): May increase adverse/toxic effects of Sympathomimetics. Specifically, the risk for elevated heart rate, hypertension, and arrhythmias may be increased. Risk C: Monitor
Esketamine (Nasal): May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Fesoterodine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Fesoterodine. 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
FluPHENAZine: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Fosphenytoin-Phenytoin: Chlorpheniramine may increase serum concentration of Fosphenytoin-Phenytoin. Risk C: Monitor
Gastrointestinal Agents (Prokinetic): Agents with Clinically Relevant Anticholinergic Effects may decrease therapeutic effects of Gastrointestinal Agents (Prokinetic). Risk C: Monitor
Gepotidacin: May decrease anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Glucagon: Agents with Clinically Relevant Anticholinergic Effects may increase adverse/toxic effects of Glucagon. Specifically, the risk of gastrointestinal adverse effects may be increased. Risk C: Monitor
Glycopyrrolate (Oral Inhalation): Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Glycopyrrolate (Oral Inhalation). Risk X: Avoid
Glycopyrrolate (Systemic): Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Glycopyrrolate (Systemic). Risk C: Monitor
Glycopyrronium (Topical): May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk X: Avoid
Guanethidine: May increase hypertensive effects of Sympathomimetics. Guanethidine may increase arrhythmogenic effects of Sympathomimetics. Risk C: Monitor
Haloperidol: QT-prolonging Agents (Indeterminate Risk - Caution) may increase QTc-prolonging effects of Haloperidol. Risk C: Monitor
Hyaluronidase: May increase vasoconstricting effects of Phenylephrine (Systemic). Management: Do not use hyaluronidase to enhance the dispersion or absorption of phenylephrine. Use of hyaluronidase for other purposes in patients receiving phenylephrine may be considered as clinically indicated. Risk D: Consider Therapy Modification
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
Iobenguane Radiopharmaceutical Products: Alpha1-Agonists may decrease therapeutic effects of Iobenguane Radiopharmaceutical Products. Management: Discontinue all drugs that may inhibit or interfere with catecholamine transport or uptake for at least 5 biological half-lives before iobenguane administration. Do not administer these drugs until at least 7 days after each iobenguane dose. Risk X: Avoid
Ipratropium (Nasal): May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Ipratropium (Oral Inhalation): May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk X: Avoid
Isoproterenol: Chlorpheniramine may increase therapeutic effects of Isoproterenol. Risk C: Monitor
Itopride: Agents with Clinically Relevant Anticholinergic Effects may decrease therapeutic effects of Itopride. 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 adverse/toxic effects of Sympathomimetics. Risk X: Avoid
Kratom: May increase CNS depressant effects of CNS Depressants. Risk X: Avoid
Landiolol: Sympathomimetics may decrease therapeutic effects of Landiolol. 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
Levosulpiride: Agents with Clinically Relevant Anticholinergic Effects may decrease therapeutic effects of Levosulpiride. Risk X: Avoid
Levothyroxine: May increase therapeutic effects of Sympathomimetics. Sympathomimetics may increase therapeutic effects of Levothyroxine. Levothyroxine may increase adverse/toxic effects of Sympathomimetics. Specifically, the risk of coronary insufficiency may be increased in patients with coronary artery disease. Risk C: Monitor
Linezolid: May increase hypertensive effects of Sympathomimetics. Management: Consider initial dose reductions of sympathomimetic agents, and closely monitor for enhanced blood pressure elevations, in patients receiving linezolid. Risk D: Consider Therapy Modification
Lisuride: May increase hypertensive effects of Alpha1-Agonists. Risk X: Avoid
Lofepramine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Lofexidine: May increase CNS depressant effects of CNS Depressants. 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
Maprotiline: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Maprotiline. Risk C: Monitor
Mavorixafor: May increase serum concentration of CYP2D6 Substrates (High risk with Inhibitors). Risk X: Avoid
Melitracen [INT]: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Melperone: May decrease therapeutic effects of Phenylephrine (Systemic). Risk C: Monitor
Mequitazine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Metergoline: May increase adverse/toxic effects of Alpha1-Agonists. 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
Methoxyflurane: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Methscopolamine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Methscopolamine. Risk C: Monitor
Metoclopramide: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
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
Mirabegron: Agents with Clinically Relevant Anticholinergic Effects may increase adverse/toxic effects of Mirabegron. Risk C: Monitor
Monoamine Oxidase Inhibitors: May increase hypertensive effects of Alpha1-Agonists. While linezolid is expected to interact via this mechanism, management recommendations differ from other monoamine oxidase inhibitors. Refer to linezolid specific monographs for details. 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
Nitroglycerin: Agents with Clinically Relevant Anticholinergic Effects may decrease absorption of Nitroglycerin. Specifically, anticholinergic agents may decrease the dissolution of sublingual nitroglycerin tablets, possibly impairing or slowing nitroglycerin absorption. Risk C: Monitor
Noscapine: CNS Depressants may increase adverse/toxic effects of Noscapine. Risk X: Avoid
OLANZapine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of OLANZapine. Risk C: Monitor
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
Opipramol: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
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
Oxatomide: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. 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
OxyBUTYnin: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of OxyBUTYnin. Risk C: Monitor
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
Paliperidone: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
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
Perampanel: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Perazine: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Pergolide: May increase hypertensive effects of Alpha1-Agonists. Risk C: Monitor
Periciazine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Perphenazine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Perphenazine. 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
Pitolisant: Antihistamines may decrease therapeutic effects of Pitolisant. Risk X: Avoid
Pizotifen: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Potassium Chloride: Agents with Clinically Relevant Anticholinergic Effects may increase ulcerogenic effects of Potassium Chloride. Management: Patients on drugs with substantial anticholinergic effects should avoid using any solid oral dosage form of potassium chloride. Risk X: Avoid
Potassium Citrate: Agents with Clinically Relevant Anticholinergic Effects may increase ulcerogenic effects of Potassium Citrate. Management: Patients on drugs with substantial anticholinergic effects should avoid using any solid oral dosage form of potassium citrate. Risk X: Avoid
Pramipexole: CNS Depressants may increase sedative effects of Pramipexole. Risk C: Monitor
Pramlintide: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. These effects are specific to the GI tract. Risk X: Avoid
Procarbazine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Promethazine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Promethazine. Risk C: Monitor
Propacetamol: May increase serum concentration of Phenylephrine (Systemic). Management: Monitor patients closely for increased side effects of phenylephrine if propacetamol is used concomitantly. Patients with underlying blood pressure issues or arrhythmias may need closer monitoring and may warrant consideration of alternative therapies. Risk C: Monitor
Propantheline: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Propantheline. Risk C: Monitor
Propiverine: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
QT-prolonging Agents (Highest Risk): QT-prolonging Agents (Indeterminate Risk - Caution) may increase QTc-prolonging effects of QT-prolonging Agents (Highest Risk). Management: Monitor for QTc interval prolongation and ventricular arrhythmias when these agents are combined. Patients with additional risk factors for QTc prolongation may be at even higher risk. Risk C: Monitor
QuiNIDine: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk C: Monitor
Ramosetron: Agents with Clinically Relevant Anticholinergic Effects may increase constipating effects of Ramosetron. Risk C: Monitor
Revefenacin: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Revefenacin. Risk X: Avoid
Rilmenidine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Rivastigmine: Agents with Clinically Relevant Anticholinergic Effects may decrease therapeutic effects of Rivastigmine. Rivastigmine may decrease therapeutic effects of Agents with Clinically Relevant Anticholinergic Effects. Management: Use of rivastigmine with an anticholinergic agent is not recommended unless clinically necessary. If the combination is necessary, monitor for reduced anticholinergic effects. Risk D: Consider Therapy Modification
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
Scopolamine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Scopolamine. Risk C: Monitor
Secretin: Agents with Clinically Relevant Anticholinergic Effects may decrease therapeutic effects of Secretin. Management: Avoid concomitant use of anticholinergic agents and secretin. Discontinue anticholinergic agents at least 5 half-lives prior to administration of secretin. Risk D: Consider Therapy Modification
Sofpironium: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Sofpironium. Risk X: Avoid
Solriamfetol: Sympathomimetics may increase hypertensive effects of Solriamfetol. Sympathomimetics may increase tachycardic effects of Solriamfetol. 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
Sympathomimetics: May increase adverse/toxic effects of Sympathomimetics. Risk C: Monitor
Tedizolid: May increase adverse/toxic effects of Sympathomimetics. Specifically, the risk for increased blood pressure and heart rate may be increased. Risk C: Monitor
Thalidomide: CNS Depressants may increase CNS depressant effects of Thalidomide. Risk X: Avoid
Thiazide and Thiazide-Like Diuretics: Agents with Clinically Relevant Anticholinergic Effects may increase serum concentration of Thiazide and Thiazide-Like Diuretics. Risk C: Monitor
Thiothixene: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Thiothixene. Risk C: Monitor
Tiapride: Agents with Clinically Relevant Anticholinergic Effects may decrease therapeutic effects of Tiapride. Risk C: Monitor
Tiotropium: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Tiotropium. Risk X: Avoid
Tolterodine: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Tolterodine. Risk C: Monitor
Topiramate: Agents with Clinically Relevant Anticholinergic Effects may increase adverse/toxic effects of Topiramate. Risk C: Monitor
Tranylcypromine: May increase anticholinergic effects of Antihistamines, First Generation. Risk X: Avoid
Tricyclic Antidepressants: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Tricyclic Antidepressants. Risk C: Monitor
Tricyclic Antidepressants: May increase therapeutic effects of Alpha1-Agonists. Tricyclic Antidepressants may decrease therapeutic effects of Alpha1-Agonists. Risk C: Monitor
Trimeprazine: May increase CNS depressant effects of CNS Depressants. Risk C: Monitor
Trimethobenzamide: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Trimethobenzamide. Risk C: Monitor
Trospium: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Trospium. Risk C: Monitor
Umeclidinium: May increase anticholinergic effects of Agents with Clinically Relevant Anticholinergic Effects. Risk X: Avoid
Valerian: May increase CNS depressant effects of CNS Depressants. 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
Zuclopenthixol: Agents with Clinically Relevant Anticholinergic Effects may increase anticholinergic effects of Zuclopenthixol. Risk C: Monitor
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
Refer to individual monographs.
Refer to individual monographs.
Some products may contain sodium.
Phenylephrine: Stimulates postsynaptic alpha-receptors, resulting in vasoconstriction, which reduces nasal congestion.
Chlorpheniramine: Competitively antagonizes histamine at histamine 1 receptor sites.
See individual agents.