Preliminary results of a controlled therapeutic trial administering INH RMP once weekly, after - or without - an initial period of continuous treatment

Intermittent treatment with RMP+INH once weekly in untreated pulmonary tuberculosis proved to be equivalent in rate and speed of sputum negativization to a 'classical' scheme of multiple phase triple therapy comprising INH SM PAS. This was even the case when the intermittent dosage had not been preceded by a 4 wk period of daily treatment. With a regimen employing 30 mg RMP/kg, side effects in the form of febrile reactions were so frequent that the RMP dose was generally reduced to 15 mg/kg. Adverse reactions then became less frequent and seemed to develop later. When 'flu' occurred, it was only exceptionally possible to maintain the mode of therapy on a reduced dosage without side effects. On the other hand, a change to daily RMP INH treatment was always successful; no reactions appeared. Typical synchronous changes of the blood picture were present during the febrile reactions; they were as transient as the symptoms. A few patients showed simultaneously a transient hyperbilirubinemia with increase of transaminases. In 2 patients the side effects advanced to severe thrombocytopenia with purpura and hemorrhages, which excluded further administration of RMP. Intermittent treatment, administering 15 mg RMP/kg and 15 mg INH/kg once weekly, is probably as effective as 30 mg RMP/kg with 15 mg INH/kg. Advantages are a reduced incidence of adverse reactions and a substantial lowering of the costs of treatment. If febrile reactions occur it is recommended that the treatment is changed to exclude further administration of RMP free regimen. The described reactions were never observed on daily administration of INH and RMP. Febrile reactions were caused by INH in 5 cases in which the INH provoked reaction always preceded the RMP induced reaction. Febrile reactions were provoked by INH alone in 2 other patients.