Study of adverse reactions to a once-weekly regimen of streptomycin plus a slow-release preparation of isoniazid in high dosage for six months.

A once-weekly regimen of streptomycin (1 g) plus a slow-release preparation of isoniazid (matrix isoniazid) in high dosage, namely 50 mg/kg body-weight for rapid inactivators of isoniazid and 35 mg/kg for slow inactivators, was prescribed for 6 months to 64 tuberculous patients (27 rapid, 37 slow). The regimen was tolerated by most the of the patients. However, 4 rapid and 3 slow inactivators had a modification of the regimen, mainly for giddiness. There were no cases of peripheral neuropathy. No adverse effects on haemopoiesis or hepatic or renal functions were observed in any of the patients. It is concluded that it is feasible to administer matrix isoniazid in dosages considerably higher than ordinary isoniazid, in once-weekly chemotherapy.