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Aminosalicylic Acid

Pronunciation

(a mee noe sal i SIL ik AS id)

Index Terms

  • 4-Aminosalicylic Acid
  • Aminosalicylate Calcium
  • Aminosalicylate Sodium
  • Para-Aminosalicylate Sodium
  • Para-Aminosalicylic Acid
  • PAS
  • Sodium PAS

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Packet, Oral:

Paser: 4 g (30 ea)

Brand Names: U.S.

  • Paser

Pharmacologic Category

  • Antitubercular Agent

Pharmacology

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%

Metabolism

Hepatic (>50%) via acetylation

Excretion

Urine (>80% as unchanged drug and metabolites)

Time to Peak

Serum: 6 hours

Half-Life Elimination

Reduced with renal impairment

Protein Binding

50% to 60%

Special Populations: Renal Function Impairment

Drug and its acetyl metabolite may accumulate.

Use: Labeled Indications

Adjunctive treatment of tuberculosis used in combination with other antitubercular agents

Contraindications

Hypersensitivity to aminosalicylic acid or any component of the formulation; severe renal impairment

Dosing: Adult

Tuberculosis (second-line agent): Oral: 8 to 12 g/day (usually 4 g 2 to 3 times daily). Note: Use in combination with other antituberculous agents (Nahid 2016).

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

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 (Nahid 2016).

Children >40 kg and Adolescents ≥15 years: Refer to adult dosing.

Dosing: Renal Impairment

Manufacturer's labeling: There are no dosage adjustments provided in the manufacturer's labeling; contraindicated in severe impairment

Alternate dosing:

Aronoff 2007: Note: Dosage adjustments are based on a usual dose of 50 mg/kg/dose every 8 hours

GFR >50 mL/minute: No dosage adjustment necessary

GFR 10 to 50 mL/minute: Administer 50% to 75% of usual dose

GFR <10 mL/minute: Administer 50% of usual dose

Administer after hemodialysis: Administer 50% of usual dose

Continuous renal replacement therapy (CRRT): Administer 50% to 75% of usual dose

Nahid 2016:

CrCl ≥30 mL/minute: No dosage adjustment necessary

CrCl <30 mL/minute: 4 g twice daily

Hemodialysis patients: 4 g twice daily; administer after hemodialysis on dialysis days

Dosing: Hepatic Impairment

There are no dosage adjustments provided in the manufacturer's labeling; use with caution

Administration

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 tomato or orange juice.

Dietary Considerations

May be taken with food.

Storage

Prior to dispensing, store granules below 15°C (59°F). Once dispensed store in refrigerator or freezer; packets may be stored at room temperature for short periods of time. Do not use if packet is swollen or if granules are dark brown or purple.

Drug Interactions

Agents with Antiplatelet Properties (e.g., P2Y12 inhibitors, NSAIDs, SSRIs, etc.): May enhance the adverse/toxic effect of Salicylates. Increased risk of bleeding may result. Monitor therapy

Ajmaline: Salicylates may enhance the adverse/toxic effect of Ajmaline. Specifically, the risk for cholestasis may be increased. Monitor therapy

Ammonium Chloride: May increase the serum concentration of Salicylates. Monitor therapy

Angiotensin-Converting Enzyme Inhibitors: Salicylates may enhance the nephrotoxic effect of Angiotensin-Converting Enzyme Inhibitors. Salicylates may diminish the therapeutic effect of Angiotensin-Converting Enzyme Inhibitors. Monitor therapy

Anticoagulants: Salicylates may enhance the anticoagulant effect of Anticoagulants. Monitor therapy

Benzbromarone: Salicylates may diminish the therapeutic effect of Benzbromarone. Monitor therapy

Blood Glucose Lowering Agents: Salicylates may enhance the hypoglycemic effect of Blood Glucose Lowering Agents. Monitor therapy

Carbonic Anhydrase Inhibitors: Salicylates may enhance the adverse/toxic effect of Carbonic Anhydrase Inhibitors. Salicylate toxicity might be enhanced by this same combination. Management: Avoid these combinations when possible.Dichlorphenamide use with high-dose aspirin as contraindicated. If another combination is used, monitor patients closely for adverse effects. Tachypnea, anorexia, lethargy, and coma have been reported. Exceptions: Brinzolamide; Dorzolamide. Consider therapy modification

Corticosteroids (Systemic): Salicylates may enhance the adverse/toxic effect of Corticosteroids (Systemic). These specifically include gastrointestinal ulceration and bleeding. Corticosteroids (Systemic) may decrease the serum concentration of Salicylates. Withdrawal of corticosteroids may result in salicylate toxicity. Monitor therapy

Dexketoprofen: Salicylates may enhance the adverse/toxic effect of Dexketoprofen. Dexketoprofen may diminish the therapeutic effect of Salicylates. Salicylates may decrease the serum concentration of Dexketoprofen. Management: The use of high-dose salicylates (3 g/day or more in adults) together with dexketoprofen is inadvisable. Consider administering dexketoprofen 30-120 min after or at least 8 hrs before cardioprotective doses of aspirin to minimize any possible interaction. Avoid combination

Ginkgo Biloba: May enhance the anticoagulant effect of Salicylates. Management: Consider alternatives to this combination of agents. Monitor for signs and symptoms of bleeding (especially intracranial bleeding) if salicylates are used in combination with ginkgo biloba. Consider therapy modification

Herbs (Anticoagulant/Antiplatelet Properties) (eg, Alfalfa, Anise, Bilberry): May enhance the adverse/toxic effect of Salicylates. Bleeding may occur. Consider therapy modification

Hyaluronidase: Salicylates may diminish the therapeutic effect of Hyaluronidase. Management: Patients receiving salicylates (particularly at larger doses) may not experience the desired clinical response to standard doses of hyaluronidase. Larger doses of hyaluronidase may be required. Consider therapy modification

Influenza Virus Vaccine (Live/Attenuated): May enhance the adverse/toxic effect of Salicylates. Specifically, Reye's syndrome may develop. Avoid combination

Loop Diuretics: Salicylates may diminish the diuretic effect of Loop Diuretics. Loop Diuretics may increase the serum concentration of Salicylates. Monitor therapy

Methotrexate: Salicylates may increase the serum concentration of Methotrexate. Salicylate doses used for prophylaxis of cardiovascular events are not likely to be of concern. Consider therapy modification

Nonsteroidal Anti-Inflammatory Agents (Nonselective): May enhance the adverse/toxic effect of Salicylates. An increased risk of bleeding may be associated with use of this combination. Nonsteroidal Anti-Inflammatory Agents (Nonselective) may diminish the cardioprotective effect of Salicylates. Salicylates may decrease the serum concentration of Nonsteroidal Anti-Inflammatory Agents (Nonselective). Consider therapy modification

Potassium Phosphate: May increase the serum concentration of Salicylates. Monitor therapy

PRALAtrexate: Salicylates may increase the serum concentration of PRALAtrexate. Salicylate doses used for prophylaxis of cardiovascular events are unlikely to be of concern. Consider therapy modification

Probenecid: Salicylates may diminish the therapeutic effect of Probenecid. Monitor therapy

Salicylates: May enhance the anticoagulant effect of other Salicylates. Monitor therapy

Sulfinpyrazone: Salicylates may decrease the serum concentration of Sulfinpyrazone. Avoid combination

Thrombolytic Agents: Salicylates may enhance the adverse/toxic effect of Thrombolytic Agents. An increased risk of bleeding may occur. Monitor therapy

Valproate Products: Salicylates may increase the serum concentration of Valproate Products. Monitor therapy

Varicella Virus-Containing Vaccines: Salicylates may enhance the adverse/toxic effect of Varicella Virus-Containing Vaccines. Reye's Syndrome may develop. Consider therapy modification

Vitamin K Antagonists (eg, warfarin): Salicylates may enhance the anticoagulant effect of Vitamin K Antagonists. Consider therapy modification

Adverse Reactions

Frequency not defined.

Cardiovascular: Pericarditis, vasculitis

Central nervous system: Brain disease

Dermatologic: Skin rash (including exfoliative dermatitis)

Endocrine & metabolic: Goiter (with or without myxedema), hypoglycemia, hypothyroidism

Gastrointestinal: Abdominal pain, diarrhea, nausea, vomiting

Hematologic & oncologic: Agranulocytosis, hemolytic anemia, leukopenia, thrombocytopenia

Hepatic: Hepatitis, jaundice

Miscellaneous: Fever

Ophthalmic: Optic neuritis

Respiratory: Eosinophilic pneumonitis

Warnings/Precautions

Concerns related to adverse effects:

• Salicylate sensitivity: Patients with sensitivity to tartrazine dyes, nasal polyps, and asthma may have an increased risk of salicylate sensitivity.

Disease-related concerns:

• Gastric ulcer: Use with caution in patients with gastric ulcer.

• 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 renal impairment.

Monitoring Parameters

Liver function; thyroid function

Pregnancy Risk Factor

C

Pregnancy Considerations

Teratogenic effects have been reported in animal reproduction studies. Salicylates have been noted to cross the placenta and enter fetal circulation. Aminosalicylic acid has been used safely during pregnancy; however, it should only be used if there are no alternatives for the treatment of multidrug-resistant tuberculosis (MMWR, 2003).

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)

• Patient may experience abdominal pain or granule shell in stool. Have patient report immediately to prescriber signs of low blood sugar (dizziness, headache, fatigue, feeling weak, shaking, tachycardia, confusion, increased hunger, or sweating), signs of liver problems (dark urine, fatigue, lack of appetite, nausea, abdominal pain, light-colored stools, vomiting, or jaundice), bruising, bleeding, confusion, chills, skin irritation, lack of appetite, severe nausea, vomiting, severe diarrhea, shortness of breath, excessive weight loss, night sweats, enlarged lymph nodes, pharyngitis, severe loss of strength and energy, or vision changes (HCAHPS).

• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for health care professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience, and judgment in diagnosing, treating, and advising patients.

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