This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
Alkalinization of urine is done in poisoning with all except ? 
Select and explain. 
A. Mrophine, B. Salicylates, C. Methotrexate, D. Barbiturates
A: Mrophine
Answer: A: Mrophine 
Explanation: Ans. is 'a' i.e., Mrophine By manipulation of the pH of glomerular filtrate, a drug can be made to ionize, become less lipid-soluble, remain in the renal tubular fluid, and so be eliminated in urine. Alkanization of urine Acidic drugs are more ionized (lipid insoluble / polar / water soluble) at alkaline pH. So, they cannot be absorbed from tubular lumen, i.e. their excretion by kidney is enhanced by alkanization of urine. Such acidic drugs are Barbiturates and Salicylate. Alkanization of urine is done by infusion of sodium bicarbonate. Urine alkalinization by NaHCO3 enhances the elimination of weak acids, e.g. Salicylates, Phenobarbitone, Chlorpropamide, formic acid and methotrexate. Acidification of urine Basic drugs are more ionized at acidic pH. So, acidification of urine should be done in poisoning of these drugs. Examples of such basic drugs are morphine, amphetamine, dexfenfluramine. Acidification of urine is done by iv infusion of arginine hydrochloride followed by ammonium chloride (NH4C1) by mouth. -- Laurence 9th/e 156