<prompt> A patient has serum creatinine of 150-300 micromolL. Which of the following require dosage reduction: March 2011AmpicillinIsoniazidGentamycinPenicillin  <response>: Ans. C: Gentamycin Drugs whose dosage are affected in mild renal insufficiency GFR 20-50 mL min or serum creatinine 150-300 micromolL are: ACE inhibitors, Aminoglycosides, chlorpropamide, digoxin, fibrates, lithium and zidovudine 