Sodium 4-aminosalicylate NEW

Sodium 4-aminosalicylate is the sodium salt of 4-aminosalicylic acid (PAS), a synthetic antibiotic primarily used to treat tuberculosis (TB).

It is structurally related to aspirin but has antimicrobial activity.

Primary Use: Tuberculosis Treatment

• Second-Line Anti-TB Drug: It was once a first-line medication but has been largely replaced by more effective, better-tolerated drugs like rifampicin and ethambutol. Today, it is classified as a Group D add-on drug by the WHO.

  Use in Drug-Resistant TB (DR-TB): Its main modern application is as a component of combination therapy for multidrug-resistant (MDR-TB) and extensively drug-resistant (XDR-TB) tuberculosis, where first-line options have failed.

  Mechanism: It acts as an antimetabolite, competitively inhibiting folate synthesis in the Mycobacterium tuberculosis bacterium, which starves it of essential nutrients for growth.

Other Medical Uses

• Inflammatory Bowel Disease (IBD): Particularly for ulcerative colitis. It is considered an older alternative to mesalazine (5-aminosalicylic acid), especially in some regions where it may be more accessible.

Key Points & Side Effects

• Administration: The sodium salt form improves water solubility, allowing it to be made into tablets or powders.

  Tolerability: It is notoriously poorly tolerated, with common side effects including severe gastrointestinal upset (nausea, vomiting, diarrhea), hypersensitivity reactions, and potential liver toxicity.

  Resistance: It is never used alone; it must always be part of a multi-drug regimen to prevent rapid development of bacterial resistance.

In summary, Sodium 4-aminosalicylate is a niche, second-line antibiotic reserved for complex cases of drug-resistant tuberculosis and occasionally used for inflammatory bowel disease.