Rifampicin + Isoniazid + Pyrazinamide + Ethambutol
Indications
Rifampicin, Isoniazid, Pyrazinamide and Ethambutol are used together to treat pulmonary and extrapulmonary tuberculosis in the intensive initial phase of treatment.
⚠️ Always consult a registered physician before taking any medicine.
Pharmacology
Rifampicin: This is a semisynthetic derivative of rifamycin. It stops bacteria from making RNA by binding to the β-subunit of DNA-dependent RNA polymerase, so the enzyme can't attach to DNA, and RNA transcription and elongation are blocked. It does not inhibit the matching enzyme in mammals. Rifampicin kills bacteria (it is bactericidal) and has a strong sterilizing effect on tubercle bacilli both inside and outside the cells. Cross-resistance has been shown only with other rifamycin derivatives.
Isoniazid: It kills actively growing tubercle bacilli by inhibiting the biosynthesis of mycolic acids, which are the major components of the cell wall of Mycobacterium tuberculosis.
Pyrazinamide: Pyrazinamide is an antituberculous drug and the pyrazine analog of nicotinamide. The precise mechanism of action is not known. Its metabolite, pyrazinoic acid, is less active in vitro, but it may be involved in the in vivo activity of pyrazinamide.
Ethambutol: Ethambutol diffuses slowly into actively growing Mycobacteria cells, for example tubercle bacilli. It inhibits the synthesis of 1 or more metabolites. This impairs cell metabolism, arrests cell multiplication and induces cell death. No cross-resistance with other agents has been demonstrated.
Spectrum of Activity: At therapeutic levels, rifampicin, isoniazid, pyrazinamide and ethambutol have shown bactericidal activity against Mycobacterium tuberculosis organisms, both intracellular and extracellular.
Pregnancy & Breastfeeding
Rifampicin has been reported to cross the placental barrier and to appear in cord blood and in breast milk. So babies and newborns of mothers who are taking rifampicin should be watched carefully for any unwanted effects.
Ethambutol given to pregnant women has produced no detectable effect on the fetus. Even so, the possible risk of birth defects in women who can bear children should be weighed carefully against the benefits of treatment. There are published reports of 5 women who took ethambutol during pregnancy without any apparent harm to the fetus.
⚠️ Talk to your doctor before taking any medicine during pregnancy or while breastfeeding.
Dosage Reference
⚠️ Reference ranges from official sources only. Consult your doctor for personalized dosing.
Side Effects & Interactions
Side Effects
No side-effect data recorded yet.