Rebound Hypertension and Acute Withdrawal Associated with Discontinuation of an Infusion of Epidural Clonidine

Abstract

A small percentage of patients with cancer pain suffer from refractory pain despite aggressive therapy. 1 Intraspinal administration of opioids and local anesthetic agents may be helpful in such settings, but their use may be limited by side effects such as motor block and hemodynamic instability. 2,3 Clonidine is a centrally acting α 2 -adrenergic agonist with established analgesic effects 4,5 and has synergistic effects with spinal opioids 6,7 and spinal local anesthetics. 8,9 Epidural clonidine produces analgesia by a spinal mechanism in patients after surgery and in those with cancer pain, 10 and it appears to be an effective treatment for severe cancer pain in patients for whom other treatments are ineffective. 11 Although the risk of acute withdrawal and rebound hypertension is well recognized with sudden cessation of systemically administered clonidine, 12 no such reports exist with regard to epidurally administered clonidine. We describe a case of acute withdrawal and rebound hypertension after abrupt cessation of epidural clonidine in a patient with intractable cancer pain.