<prompt> Maintenance of high urinary pH is impoant during methotrexate treatment becauseBladder irritation is reducedIt decreases renal tubular secretion of methotrexateLeucovorin toxicity is increased in a dehydrated patientMethotrexate is a weak acid  <response>: Ref-KDT 6e 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 