PAS
Synonyms :
4-Aminosalicylic acid, Para-Amino Salicylic acid
Mechanism :
It is a highly-specific bacteriostatic agent active against M. tuberculosis. Its mechanism of action is thought to be similar to the sulphonamides, a competitive antagonism with PABA.
Indication :
- Adjunctive treatment of tuberculosis used in combination with other antitubercular agents (second line agent)
Contraindications :
Hypersensitivity to aminosalicylic acid or any component of the formulation; severe renal impairment.
Dosing :
Children ≤40 kg and Adolescents <15 years:
Oral: 200 to 300 mg/kg/day (usually 100 mg/kg/dose 2 to 3 times daily).
Children >40 kg and Adolescents ≥15 years:
Oral: 8 to 12 g/day (usually 4 g given 2 to 3 times daily).
Adverse Effect :
Pericarditis, vasculitis, brain disease, skin rash, goitre, hypothyroidism, hypoglycaemia, agranulocytosis, haemolytic anemia, leukopenia, thrombocytopenia, hepatitis, jaundice, optic neuritis, eosinophilic pneumonitis.
Interaction :
Agents with Antiplatelet Properties (e.g., P2Y12 inhibitors, NSAIDs, SSRIs, etc.): May enhance the adverse/toxic effect of Salicylates.
Angiotensin-Converting Enzyme Inhibitors: Salicylates may enhance the nephrotoxic effect of Angiotensin-Converting Enzyme Inhibitors.
Blood Glucose Lowering Agents: Salicylates may enhance the hypoglycemic effect of Blood Glucose Lowering Agents.
Carbonic Anhydrase Inhibitors: Salicylates may enhance the adverse/toxic effect of Carbonic Anhydrase Inhibitors.
Methotrexate: Salicylates may increase the serum concentration of Methotrexate.
Sulfinpyrazone: Salicylates may decrease the serum concentration of Sulfinpyrazone.
Hepatic Dose :
contraindicated in severe impairment.