Adverse reactions to daily and intermittent rifampicin regimens for pulmonary tuberculosis in Hong Kong.

This paper reports the nature, incidence, and severity of adverse reactions to regimens of rifampicin and ethambutol given once weekly, twice weekly, or daily and to a standard reserve regimen in a total of 330 Chinese failure patients who completed at least six months' chemotherapy in a therapeutic comparison in Hong Kong.The adverse reactions which occurred on the regimens of intermittent rifampicin were termed cutaneous, abdominal, "flu", and respiratory; in addition, purpura and abnormal liver function tests were encountered. There was an association of adverse reactions with the interval between doses and with the dose size of rifampicin, the highest incidence occurring with once-weekly rifampicin in high dosage. A procedure was developed for managing adverse reactions to intermittent rifampicin. Of 202 patients treated with intermittent rifampicin 60 developed adverse reactions, but in only 7 (3%) was it necessary to terminate the drug, though a further 10 (5%) were changed to daily rifampicin. On daily rifampicin, generalized hypersensitivity, cutaneous reactions, (one with purpura), and impaired liver function were encountered. Adverse reactions on the standard ethionamide, pyrazinamide, and cycloserine regimen were frequent and some were serious.