Drug X normal administered to patients at a rate of 50mg/hr. Elimination of the drug X from body takes place as Hepatic metabolism 10% Biliary secretion 10% Renal excretion 80% This drug has to be administered to A 65 years old patient Uttam Singh, with a GFR of 60ml/min.(assuming normal GFR is 1w0ml/min). Liver and biliary functions and normal in the patient. What will be the dose rate of the drug X in this patient

Ref-Goodman and Gillman 12/e p36-37 In this question 80 percent of drug is eliminated by renal route and 20percent by non-renal routes (10 percent by hepatic metabolism and 10 percent by biliary secretion) . This patient has 50 percent renal function (60 ml/ min of GFR instead of 120 ml/min). Thus, the drug that can be eliminated in this person is 20percent (Non-renal route) + 40 percent (Renal route, 50 percent of 80 percent) = 60 percent Thus, the dose rate should be 60 percent of the original. i.e. 50 mg/hr x 60 percent = 30 mg/hr.