isoniazid + rifampicin + ethambutol

The "HRE" regimen refers to a fixed-dose combination or co-administration of three first-line anti-tuberculosis drugs: isoniazid (H), rifampicin (R), and ethambutol (E). This regimen is used as the continuation phase of tuberculosis treatment, particularly in areas with high rates of resistance to isoniazid. The mechanism of action involves inhibition of mycolic acid synthesis in the bacterial cell wall by isoniazid, inhibition of DNA-dependent RNA polymerase by rifampicin, and disruption of cell wall formation by ethambutol. The primary indication for this combination is drug-sensitive pulmonary tuberculosis during the continuation phase after an initial intensive phase that typically includes pyrazinamide as well. The World Health Organization recommends this regimen for four months following an initial two-month intensive phase with HRZE (isoniazid, rifampicin, pyrazinamide, and ethambutol) in certain populations or settings[1][3][4][6][7][8].

Other names

HRE regimenisoniazid-rifampicin-ethambutol combination