Version July 2025
Note: Paser oral packets have been discontinued in the United States for >1 year.
Tuberculosis, drug resistant (alternative agent): Note: Expert consultation for optimal regimen and duration of treatment is advised.
Oral: 4 g two to three times daily as part of an appropriate combination regimen (Ref).
CrCl ≥30 mL/minute: No dosage adjustment necessary (Ref).
CrCl <30 mL/minute: Contraindicated in patients with severe impairment in the manufacturer’s labeling; however, some experts suggest a dose of 4 g twice daily (Ref).
Patients on hemodialysis: Contraindicated in patients with end-stage renal disease in the manufacturer’s labeling; however, some experts suggest a dose of 4 g twice daily, administered after hemodialysis on dialysis days (Ref).
There are no dosage adjustments provided in the manufacturer's labeling; use with caution
Refer to adult dosing.
Tuberculosis (second-line agent):
Children ≤40 kg and Adolescents <15 years: Oral: 200 to 300 mg/kg/day (usually 100 mg/kg/dose 2 to 3 times daily). Note: Use in combination with other antituberculous agents (Ref).
Children >40 kg and Adolescents ≥15 years: Refer to adult dosing.
There are no dosage adjustments provided in the manufacturer's labeling; contraindicated in severe impairment.
There are no dosage adjustments provided in the manufacturer's labeling; contraindicated in severe impairment.
The following adverse drug reactions are derived from product labeling unless otherwise specified.
Frequency not defined:
Gastrointestinal: Abdominal pain, diarrhea, nausea, vomiting
Hypersensitivity: Hypersensitivity reaction
Hypersensitivity to aminosalicylic acid or any component of the formulation; severe or end-stage renal disease
Concerns related to adverse effects:
• Salicylate sensitivity: Patients with nasal polyps and asthma may have an increased risk of salicylate sensitivity.
Disease-related concerns:
• Hepatic impairment: Use with caution in patients with hepatic impairment.
• Renal impairment: Use with caution in patients with renal impairment; contraindicated in patients with severe or end-stage renal disease.
Paser oral packets have been discontinued in the United States for >1 year.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product
Packet, Oral:
Paser: 4 g (30 ea [DSC])
No
Pack (Paser Oral)
4 g (per each): $8.00
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: May be administered with food. Do not use granules if packet is swollen or if granules are discolored (ie, brown or purple). Granules may be sprinkled on applesauce or yogurt (do not chew) or suspended in an acidic beverage (eg, tomato or orange juice).
Oral: Do not use granules if packet is swollen or if granules are discolored (ie, brown or purple). Granules may be sprinkled on applesauce or yogurt (do not chew) or suspended in tomato or orange juice.
Tuberculosis: Treatment of tuberculosis, as part of an appropriate combination regimen, in the setting of multidrug resistance or intolerance to other agents.
None known.
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.
Bacillus clausii: Antibiotics may decrease therapeutic effects of Bacillus clausii. Management: Bacillus clausii should be taken in between antibiotic doses during concomitant therapy. Risk D: Consider Therapy Modification
BCG (Intravesical): Antibiotics may decrease therapeutic effects of BCG (Intravesical). Risk X: Avoid
BCG Vaccine (Immunization): Antibiotics may decrease therapeutic effects of BCG Vaccine (Immunization). Risk C: Monitor
Cholera Vaccine: Antibiotics may decrease therapeutic effects of Cholera Vaccine. Management: Avoid cholera vaccine in patients receiving systemic antibiotics, and within 14 days following the use of oral or parenteral antibiotics. Risk X: Avoid
Dapsone (Topical): May increase adverse/toxic effects of Methemoglobinemia Associated Agents. Risk C: Monitor
Fecal Microbiota (Live) (Oral): May decrease therapeutic effects of Antibiotics. Risk X: Avoid
Fecal Microbiota (Live) (Rectal): Antibiotics may decrease therapeutic effects of Fecal Microbiota (Live) (Rectal). Risk X: Avoid
Immune Checkpoint Inhibitors (Anti-PD-1, -PD-L1, and -CTLA4 Therapies): Antibiotics may decrease therapeutic effects of Immune Checkpoint Inhibitors (Anti-PD-1, -PD-L1, and -CTLA4 Therapies). Risk C: Monitor
Lactobacillus and Estriol: Antibiotics may decrease therapeutic effects of Lactobacillus and Estriol. 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
Mycophenolate: Antibiotics may decrease active metabolite exposure of Mycophenolate. Specifically, concentrations of mycophenolic acid (MPA) may be reduced. 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
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
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
Sodium Picosulfate: Antibiotics may decrease therapeutic effects of Sodium Picosulfate. Management: Consider using an alternative product for bowel cleansing prior to a colonoscopy in patients who have recently used or are concurrently using an antibiotic. Risk D: Consider Therapy Modification
Tenofovir Disoproxil Fumarate: Aminosalicylic Acid may decrease serum concentration of Tenofovir Disoproxil Fumarate. Risk C: Monitor
Typhoid Vaccine: Antibiotics may decrease therapeutic effects of Typhoid Vaccine. Only the live attenuated Ty21a strain is affected. Management: Avoid use of live attenuated typhoid vaccine (Ty21a) in patients being treated with systemic antibacterial agents. Postpone vaccination until 3 days after cessation of antibiotics and avoid starting antibiotics within 3 days of last vaccine dose. Risk D: Consider Therapy Modification
Evaluate pregnancy status prior to treatment of multidrug-resistant tuberculosis in females of reproductive potential. Females of reproductive potential should use effective contraception during treatment for multidrug-resistant tuberculosis (Esmail 2018).
Tuberculosis (TB) disease (active TB) is associated with adverse fetal outcomes, including intrauterine growth restriction, low birth weight, preterm birth, and perinatal death (Esmail 2018; Miele 2020), as well as adverse maternal outcomes, including increased risks for anemia and cesarean delivery. Placental transmission may rarely occur with active maternal disease (Miele 2020).
Data are limited for use of second-line drugs in pregnancy (ie, aminosalicylic acid). Individualized regimens should be utilized to treat multidrug-resistant tuberculosis in pregnant patients; evidence to support a specific regimen is not available (ATS/CDC/ERS/IDSA [Nahid 2019]; WHO 2020).
Aminosalicylic acid is present in breast milk.
Following the administration of oral aminosalicylic acid 4 g to a lactating woman (postpartum age not presented), peak maternal serum concentrations were 70.1 mcg/mL at 1 hour, peak breast milk concentrations were 1.1 mcg/mL at 3 hours, and the half-life of aminosalicylic acid in the breast milk was calculated to be 2.5 hours (Holdiness 1984). Using the peak breast milk concentration from this single case report, the relative infant dose (RID) of aminosalicylic acid was calculated to be <1% compared to an infant therapeutic dose of 200 to 300 mg/day (Tran 1998). In general, breastfeeding is considered acceptable when the RID of a medication is <10% (Anderson 2016; Ito 2000). Because information is limited, infants exposed to aminosalicylic acid via breast milk should be monitored for adverse events such as anorexia, diarrhea, nausea, vomiting, or hypersensitivity reactions (Tran 1998).
Patients with multidrug-resistant tuberculosis and a sputum smear-positive test should avoid breastfeeding when possible (Esmail 2018).
Liver function; thyroid function; CBC; serum electrolytes (AST/CDC/ERS/IDSA [Nahid 2019]); serum concentrations (peak) as clinically indicated (Asultan 2014).
Timing of serum samples: Draw peak approximately 6 hours postdose (Alsultan 2014).
Therapeutic level: Peak: 20 to 60 mcg/mL; consider dose increase if <10 mcg/mL (Alsultan 2014).
Aminosalicylic acid (PAS) is a highly-specific bacteriostatic agent active against M. tuberculosis. Structurally related to para-aminobenzoic acid (PABA) and its mechanism of action is thought to be similar to the sulfonamides, a competitive antagonism with PABA; disrupts plate biosynthesis in sensitive organisms.
Absorption: Readily, >90%
Protein binding: 50% to 60%
Metabolism: Hepatic (>50%) via acetylation
Half-life elimination: Reduced with renal impairment
Time to peak, serum: 6 hours
Excretion: Urine (>80% as unchanged drug and metabolites)
Altered kidney function: Drug and its acetyl metabolite may accumulate.
