SHOULD ISONIAZID BE USED IN RETREATMENT OF TUBERCULOSIS DESPITE ACQUIRED ISONIAZID RESISTANCE

Publisher Website
Google Scholar
Abstract
The use of high-dose isoniazid in retreatment regimes for tuberculosis [in humans], despite acquired isoniazid resistance, could possibly improve therapeutic results if all or part of the organisms were resistant to only low concentrations of that drug. Organisms resistant to low concentrations of isoniazid were shown, on occasion, to be resistant to 2 of the retreatment drugs, ethionamide and pyrazinamide, whereas higher degrees of isoniazid resistance are associated with susceptibility to these drugs. Use of high-dose isoniazid might improve results in retreatment with ethionamide and pyrazinamide by eliminating any organisms with low degrees of isoniazid resistance that have associated ehtionamide and pyrazinamide resistance. Two clinical trials concerning this topic were reported. A controlled retreatment trial with various combinations of ethionamide, cycloserine and pyrazinamide with and without conventional low doses of isoniazid (300 mg/day) showed no benefit when isoniazid was added. A noncontrolled trial using ethionamide and pyrazinamide with and without high doses of isoniazid, 1-1.5 g/day, showed marked benefit with the added isoniazid. In view of these conflicting data, the use of high-dose isoniazid in retreatment regimens needs further study, which could probably be carried out in the developing countries.

This publication has 0 references indexed in Scilit: