[Pharmacokinetics of haloperidol in patients on hemodialysis]

Psychotic symptoms among patients receiving hemolytic dialysis (HD) are quite common, while studies showing pharmacokinetics and clearances of neuroleptics in such patients are few. In such instances, previous studies recommended a single administration of neuroleptics with about 1/3 to 1/2 of the normal dose for patients without renal failure. We made a study of 4 cases of delirious patients receiving HD and investigated the relationship between a daily dose of haloperidol (HP), its blood concentration and changes of delirium symptoms before and after HD. Oral or intravenous doses of HP (12-24 mg) were required for the improvement of delirium. Blood concentration increased in proportion to the HP dosage in all patients, and its average was significantly higher than that of the control group. Approximately 25% of clearance was found before and after HD. These studies suggest that the HP dosage for HD patients needs to be larger than previously assumed. Changes in the pharmacokinetics of HP in HD patients seemed to be influenced by a variety of factors such as binding rate with blood serum albumin and HP, metabolic pathway of HP, and sensitivity of HP in the brain.