The standard TB regimen is a six month course of antibiotics but the duration and drugs used may vary according to a patient’s age, type of TB infection, and whether they have been treated before.  Treating TB takes longer than treating other types of bacterial infections because the bacteria that cause TB grow slowly, and die slowly.  The standard six month course of treatment consists of two phases.  The first phase lasts two months and is called the intensive phase.  The second phase lasts four months and is called the continuous phase.

This is a very useful quick reference guide to first and second-line TB drugs from the WRHI.

PAS (Para-aminosalicylic acid or PASER); PAS-sodium (Para-aminosalicylic acid sodium)

PAS was discovered in 1944. Initially, PAS was used to treat TB, but with the discovery of other more potent drugs including rifampicin, its use in first line regimens was discontinued. PAS is still useful as part of a treatment regimen for XDR TB although its benefit is limited and it is extremely toxic.

Prothionamide (Pto)