Rifampin plus Isoniazid in Initial Therapy of Pulmonary Tuberculosis and Rifampin and Ethambutol in Retreatment Cases

¹ Chest and Laboratory Services Departments, Ruchill Hospital, Glasgow, Scotland

Eighty-eight patients with previously untreated, baceriologically-positive pulmonary tuberculosis were given rifampin 600 mg daily and isoniazid 300 mg daily. Bacteriologic conversion was achieved in 81 (92 percent) in three months and in all 88 patients in six months.

Sixty-six patients with previously treated bacteriologically-positive pulmonary tuberculosis were given rifampin 600 mg daily and ethambutol 25/15 mg per kilo bodyweight daily. Bacteriologic conversion was achieved in 58 (88 percent) in three months and in all but one of the 66 patients in months.

Rifampin side effects were negligible when it was combined with ethambutol. When combined with isoniazid, two severe hypersensitivity reactions were observed and disturbance of liver function was fairly frequent, though never severe. Isoniazid, therefore, appears to increase the tendency of rifampin to cause hepatotoxicity. Nevertheless, rifampin would seem indicated in first line treatment of pulmonary tuberculosis, as well as in the management of cases previously treated.