Opioid withdrawal syndrome on switching from hydromorphone to alfentanil.

Opioid switching is increasingly practiced. This patient did not tolerate morphine, oxycodone or hydromorphone due to opioid toxicity. Finally switch to alfentanil was performed. The patient developed classical opioid withdrawal symptoms and signs from discontinuation of the hydromorphone. Administration of small aliqouts of this drug reversed the symptoms. The existance of incomplete cross tolerance between hydromorphone and alfentanil is demonstrated.