Ethambutol in tuberculosis: time to reconsider?

Revision of treatment regimens in Malawi Table 1 shows the regimens used in Malawi for new cases of TB. Having used thiacetazone for approximately 12 years, the Malawi National TB Programme removed it from its essential drug list in January 1997 and substituted ethambutol. Most paediatric cases of TB fall into the category of smear negative pulmonary TB. The proposed new regimen consists of a two month initial phase (with the first two weeks spent in hospital) of supervised rifampicin, isoniazid, and pyrazinamide given three times a week, followed by a six month continuation phase of daily unsupervised isoniazid and ethambutol. For those children with smear positive pulmonary TB and serious forms of extrapulmonary TB, ethambutol is added to the two month initial supervised phase of treatment. Patients with TB meningitis are an exception to the proposed changes and will continue to be given the current regimen.