Isoniazid in the treatment of pulmonary tuberculosis

Abstract

70 patients in hospital or attending the chest clinic with various forms of pulmonary tuberculosis were treated with isoniazid for three months at an average dose of 4–6 mg./kg. Subjective improvement was claimed by 60, with gains of weight in 56, of whom 27 gained more than 1 st. A favourable effect was observed on fever, with resurgence of appetite, strength and well-being. Nearly all patients experienced a considerable decrease of cough and sputum, about half entirely losing their cough. Sputum conversion occurred in 22 of 41 positive cases at the end of three months. 5 reverted later to positive. Screening tests for drug resistance at 4 μg./ml. were carried out on 16 patients. Partial or complete resistance at this high level were shown by 4 patients, at nine, eleven, fourteen and sixteen weeks. After twelve weeks' treatment isoniazid was continued in most cases and there has been clinical relapse in a few. It is therefore suggested that isoniazid should not be given for longer than eight weeks without the concurrent use of streptomycin. Variations in E.S.R. have been well correlated with changes in clinical condition. Radiological improvement occurred in 35 patients; 14 showed very considerable regression. Serious toxic effects were not encountered, though haemoptysis occurred in 5 patients for the first time while under treatment. Present indications for isoniazid are: as a substitute for streptomycin in the domiciliary treatment of tuberculosis, and tuberculous laryngitis; where streptomycin has failed through drug resistance or intolerance, or cannot be given because of PAS intolerance. It is also indicated in conjunction with other drugs for patients with severe toxaemia.