A middle-aged man with chronic renal failure is diagnosed to have sputum-positive pulmonary tuberculosis. His creatinine clearance is 25 ml/min. All of the following drugs need modification in doses EXCEPT :: (A) Isoniazid, (B) Streptomycin, (C) Rifampicin, (D) Ethambutol
Answer is C. Rifampicin is secreted in bite, so it does not require dose adjustment in renal failure.