<prompt> A middle aged man with chronic renal failure is diagnosed to have sputum-positive pulmonary tuberculosis. His creatinine clearance is 25 mlmin. All of the following drugs need modification in doses except:IsoniazidStreptomycinRifampicinEthambutol  <response>: Ans. C RifampicinRef: Katzung 11e p826, KDT 8the p818Rifampicin is secreted in bile, so it does not require dose adjustment in renal failure 