Comparative study between the effect of pre-emptive use of oral Gabapentin and Pregabalin on acute post-operative pain after elective gynecological surgeries performed under spinal anesthesia

Abstract

The relief of postoperative pain is a subject, which has been receiving an increasing amount of attention in the past few years. Pre-emptive analgesia is the administration of analgesics prior to onset of noxious stimuli, which aims to decrease acute pain after tissue injury and to inhibit the persistence of post-operative pain and the development of chronic pain. Various drugs including gabapentin and pregabalin have been used as pre-emptive analgesics. Gabapentin and pregabalin are structural analogues of gamma amino butyric acid that were introduced as antiepileptic drugs and have been extensively used to treat painful neuropathies. Their mechanism of action is likely mediated by binding to the presynaptic voltage-gated calcium channels, inhibiting calcium influx via these channels, and subsequently inhibiting the release of excitatory neurotransmitters from the primary afferent nerve fibers in the pain pathway. Several clinical trials studying perioperative use of gabapentin and pregabalin, with a variety of surgical procedures producing visceral and somatic injury, have found significant reduction in postoperative analgesic requirements and others a reduction in early and late postoperative pain.