Prolonged opioid antagonism with naloxone in chronic renal failure

Respiratory depression secondary to morphine intoxication occurred in an el derly patient with chronic renal failure (CRF). It was reversed with a cont inuous infusion of naloxone. Approximately 11 hours after the infusion was discontinued, the patient relapsed into respiratory depression consistent w ith opioid intoxication. He was rechallenged with a naloxone infusion with resolution of the opioid effects. This case suggests prolonged antagonism o f opioid effects inconsistent with naloxone's reported pharmacologic effect s. Serum naloxone concentrations measured after the end of the infusion sug gest that the drug's pharmacokinetics were significantly altered. Further r esearch is necessary to characterize pharmacokinetic changes that occur in CRF. In the absence of this information, similar patients should be closely monitored for relapse of respiratory depression after naloxone is disconti nued.