Analgesic Potentials of Preoperative Pregabalin,Magnesium Sulphate and Their Combination in Acute Post-thoracotomy Pain

Magnesium (Mg) acts on N-methyl-D-aspartate (NMDA) receptor as a non-competitive antagonist with antinociceptive effects. Gabapentin is an alkylated analogue of gammaaminobutyric acid (GABA) developed primarily as an anticonvulsant drug. It was described as an analgesic drug for the treatment of neuropathic pain in the 1990s. Although it is named Gabapentin,it does not bind at the GABA A or GABA B receptor. It binds with high affinity for the α2δ subunit of the presynaptic voltage-gated calcium channels, which reduce calcium-dependent release of pro-nociceptive neurotransmitters in the pain pathways. Pregabalin is a structural analogue of GABA was introduced after Gabapentin. If we used these drugs in combination to opioids preoperatively as preventive analgesia may decrease postoperative opioid consumption and pain intensity.