Rifampicin may affect estrogen metabolism, Bonn investigator says.

Abstract

The possible influence of rifampicin on the biogenesis and metabolism of estrogens was reported at the 9th Acta Endocrinologica Congress in Oslo. It is of direct importance to women taking rifampicin and oral contraceptives. Menstrual cycle disturbances have previously been observed in women with tuberculosis who are using drugs. Of 82 patients under treatment with rifampicin and oral contraceptives, 58 experienced menstrual disturbances, reported Dr. Lieselotte Nocke-Finck of the Institute for Clinical Biochemistry at the University of Bonn, West Germany. In contrast, of 26 patients receiving streptomycin and oral contraceptives, only 1 suffered a menstrual alteration. Investigating these clinical observations, Dr. Nocke-Finck studied the urinary excretion of estrogens of patients who received, alternatively during 1 menstrual cycle, either streptomycin or rifampicin. Her results showed that the patients could be divided into 3 groups. The 1st consisted of 5 patients who were treated with rifampicin and experienced spotting. In these 5, the urinary excretion of estrogens was increased up to 10 times. The 2nd group contained 3 patients on rifampicin therapy who had silent menstruation and urinary estrogen excretion that was decreased between 10% and 90%. The 3 patients in the 3rd group showed no menstrual alterations but considerable variation of estrogen excretion.