Abstract

For over 20 years the standard initial treatment of pulmonary tuberculosis has been triple therapy with streptomycin, PAS and isoniazid followed, when the results of susceptibility tests on the patient’s tubercle baccilli become known, by a combination of 2 drugs, either PAS and isoniazid daily or streptomycin and isoniazid twice weekly for up to 2 years. This treatment has been very effective, and indeed during recent years eighteen months’ chemotherapy with these regimens has been considered adequate.¹ One study followed up for up to 18 years 825 patients treated in this way between 1955 and 1960. Only 33(4%) relapsed with positive sputum, and in all but 3 of these this was due to poor cooperation by the patient.² PAS is unpleasant to take and bulky to carry and it often causes adverse reactions. Streptomycin must be injected and it can cause VIIIth nerve damage and allergic reactions.