Alkalinization of urine is required to treat toxicity of all except:: (A) Salicylates, (B) Barbiturates, (C) Amphetamine, (D) Methotrexate
Answer is C. Changes in urinary pH affect tubular reabsorption of drugs that are paially ionized - * Weak bases are ionize more and are less reabsorbed in acidic urine.* Weak acids ionize more and are less reabsorbed in alkaline urine. Urine is alkalinized in barbiturate, methotrexate and salicylate poisoning.