Prolonged Release Extradural Morphine

Abstract

SummaryThe effects of extradural administration of a microcrystalline preparation of morphine (Duromorph) were studied in 5 patients with postoperative or malignant pain. As assessed by pain scores on a visual analogue scale, the effects of the analgesic were extremely variable; the best results were obtained in patients with postoperative pain. Two patients with chronic pain due to malignant disease developed slow respiratory rates. The plasma concentration of morphine usually followed a biphasic pattern; an initial peak between 0.5 and 1.5 hours was succeeded by a second, large peak between 6 and 12 hours. There was little or no apparent relation between the plasma concentration of morphine and the relief ofpain, suggesting that Duromorph may have a local effect on the spinal cord.

Controlled release ibuprofen-poloxamer gel for epidural use – A pharmacokinetic study using microdialysis in pigs

“…The spinal analgesic and anti-inflammatory effects of nonsteroidal anti-inflammatory drugs (NSAIDs) seem to be related to their ability to inhibit cyclo-oxygenase enzyme and the synthesis of prostaglandins [16,17], thus blocking the excessive sensitivity to pain induced by the activation of the spinal glutamate and substance P receptors [18,19]. Since NSAIDs act through an enzymatic system instead of receptors the risks of spinal opioids, such as tolerance, respiratory depression, urinary problems, motor blockade and dependence [20] are unlikely to develop in epidural use of NSAIDs. Ibuprofen is known as a potent oral NSAID, but has been found to be able to act also on the spinal cord reducing pain even more efficiently after intrathecal administration than after systemic administration [18].…”