ziconotide and Pain--Postoperative

We report on the intrathecal use of ziconotide in three patients with idiopathic facial pain after surgery of the mouth, jaw or face and one patient with neuropathic pain after damage of the lingual nerve. The therapy was successful in three patients but one patient with idiopathic facial pain had pain relief only during the test phase of ziconotide with an external pump and not after implanting the Synchromed® pump. With intrathecal morphine therapy this patient achieved good pain relief. We recommend that patients with neuropathic facial pain should be treated with ziconotide after implementation of guideline-based therapy. In the test phase the ziconotide dose should be increased by 0.6 µg/day per week after an initial dose of 0.6-1.2 µg/day to avoid side-effects.

Topics: Adult; Analgesics, Non-Narcotic; Dose-Response Relationship, Drug; Ethmoid Sinusitis; Facial Neuralgia; Female; Humans; Infusion Pumps, Implantable; Injections, Spinal; Lingual Nerve Injuries; Maxillary Sinusitis; Mucocele; omega-Conotoxins; Pain Measurement; Pain, Postoperative; Tooth Extraction; Treatment Outcome; Trigeminal Neuralgia; Young Adult

Ziconotide (SNX-111), a selective blocker of neuronal N-type voltage-sensitive calcium channels, is antinociceptive when it is administered intrathecally. It is currently under clinical investigation for the treatment of malignant and non-malignant pain syndromes. The present study was undertaken to compare and contrast antinociceptive properties of ziconotide, morphine and clonidine in a rat model of post-operative pain. Post-operative pain was produced by making a longitudinal incision through the skin, fascia, and muscle of the plantar aspect of the left hindpaw. This procedure produced immediate (0.5 h after surgery) and long-lasting (4-7 days post-surgery) heat hyperalgesia and mechanical allodynia in the injured hindpaw. Pain thresholds in the contralateral hindpaw were unaffected. Administered one day after incisional surgery, intrathecal ziconotide blocked established heat hyperalgesia in the injured hindpaw in a dose-dependent manner yielding an ED(50)4 h) but reversible (<24 h) blockade of established mechanical allodynia. Administered one day after surgery, intrathecal bolus injection of morphine dose-dependently blocked heat hyperalgesia in the injured hindpaw with an ED(50) of 1.6 microg (2.1 nmol) and heat nociceptive responses in the normal hindpaw with an ED(50) of 2.7 microg (3.6 nmol). The effects were immediate and short-lasting (

Topics: Analgesics; Analgesics, Opioid; Animals; Calcium Channel Blockers; Calcium Channels, N-Type; Clonidine; Hot Temperature; Hyperalgesia; Injections, Spinal; Male; Morphine; Nociceptors; omega-Conotoxins; Pain, Postoperative; Physical Stimulation; Rats; Rats, Sprague-Dawley