Drug X is normally administered to patients at a rate of 50 mg/hour. 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 Uttaam Singh, with a GFR of 60 ml/min. (assuming normal GFR is 120ml/min). Liver and biliary functions are normal in this patient. What should be the dose rate of drug X in this patient?
* In this question 80 percent of drug is eliminated by renal route and 20 percent 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 20 percent (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.
50 mg/hour
30 mg/hr
25 mg/hr
100 mg/hr.
Pharmacokinetics