Maintenance of high urinary pH is impoant during methotrexate treatment because: (A) Bladder irritation is reduced, (B) It decreases renal tubular secretion of methotrexate, (C) Leucovorin toxicity is increased in a dehydrated patient, (D) Methotrexate is a weak acid
Answer is D. Ref-KDT 6/e p823 Methotrexate is a weak acid and basic reabsorbed in acids urinary PH. Higher plasma concentration may result in toxicity. Therefore to decrease the reabsorptiion through renal tubes urinary pH must be maintained