<prompt> Dose reduction is required in renal failure with all except:Amphotericin BVancomycinDoxycyclineGentamicin  <response>: Ans. C. DoxycyclineDose reduction is needed in case of following conditions: Drug causing nephrotoxicity as adverse drug reaction Drug excreted through renal routeAmphotericin B is most nephrotoxic among antifungals. Even liposomal preparations of amphotericin B c-AMB, LAMB, ABCD, ABLC are nephrotoxic, though less as compared to conventional Amphotericin B.More than 90 of vancomycin is excreted through glomerular filtration.In case of renal failure, there may be less excretion which leads to toxicity of Vancomycin due to its striking accumulation in body ototoxicity, nephrotoxicity, red man syndrome. Half-life of vancomycin can increase to 6-10 days in case of anephric patients.Gentamicin is an aminoglycoside. Aminoglycosides are most potent to cause both ototoxicity and nephrotoxicity. Aminoglycosides are excreted almost entirely by glomerular filtration. High concentration of aminoglycosides is found in otic fluid and by virtue of the process of elimination: high concentration is found in urinary tract.Dose modification required in renal failure. Cockcroft-Gault equationCCr 72xSCr 140-AgexWeightkg CCr creatinine clearance expressed in mLmin; SCr serum creatinine expressed in mgdLAmong tetracyclines, minocycline and doxycycline are safe in renal impairment cases. Doxycycline does not cause nephrotoxicity and is excreted through bile. Other tetracyclines can cause Fanconi syndrome characterized by toxic metabolite accumulation tetracyclines and epihydrotetracyclines.So, answer is Doxycycline. 