For extended drug resistance tuberculosis drugs such as clofazimine and linezolid can be added to regimen.
(A) Continuous phase is Isoniazid + Rifampicin+pyrazinamide for 2 months
(B) Initial phase is Isoniazid + Rifampicin for 4 months
(C) Initial phase is Isoniazid + Rifampicin + Pyrazinamide + Ethambutol for 2 months
(D) Continuous phase is Dapsone + Rifampicin for 6 months
Various MDR regimens are available for 9 months to 2 years based on the progression of disease. One of the recommended regimen includes 6 months treatment with two phases. Initial phase is for two months with Isoniazid + Rifampicin + Pyrazinamide + Ethambutol in the regimen and continuous phase is for 4 months with Isoniazid + Rifampicin in the regimen.
Rifampin is an enzyme inducer and can increase the metabolism of protease inhibitor like saquinavir resulting in failure of HIV treatment. Rifabutin should be added in to regimen instead of rifampin as the former is not an enzyme inducer and has less drug interactions.
Ethambutol can produce optic neuritis resulting in indiscrimination between red and green color.
(A) Isoniazid, optic neuritis
(B) Rifampin, orange-red tinge
(C) Capreomycin, ototoxicity
(D) Pyrazinamide, gout
Various drugs used in TB and their main side effects are as follows. Isoniazid peripheral neuropathy, hemolytic anemia; Rifampin Liver failure and orange tinge to saliva and urine ; Pyrazinamide hyperuricemia ; Ethambutol Optic neuritis; Cycloserine neurotoxicity; Capreomycin ototoxicity; p-Aminosalicylic acid, Ethionamide Hepatotoxicity and hypothyroidism.