A possible exception is rifampin , the antibiotic prescribed for tuberculosis .
可能的例外就是利福平,这种抗生素是专为治疗肺结核研制的。
Studies clearly show that rifampin decreases the effectiveness of birth control pills in preventing ovulation .
研究清楚显示,利福平会降低避孕药抑制排卵的效力。
Rifampin does lower pregnancy-protecting hormone levels induced by birth control pills , but whether the effect is large enough to increase pregnancy risk is unclear .