title: Gabapentin enhances the analgesic response to morphine in acute model of pain in male rats.
abstract: Whenever opioids as drug of choice result in inadequate analgesia, the combinational therapy would be the solution. In this study the co-administration of gabapentin with morphine is evaluated in acute model of pain. Therefore the antinociceptive effect of gabapentin (30 or 90 mg/kg, s.c.) and morphine (0.5, 1 or 3 mg/kg, s.c.) alone or in combination were measured by tail-flick test in intact adult male rats. Control rats received normal saline. Tail-flick latency time and Area Under Curve (AUC), as antinociception index were calculated for each groups. There was not any significant difference between the antinociceptive response of 0.5 mg/kg morphine and 30 mg/kg gabapentin as compared to controls, but co-administration of these subanalgesic doses increased significantly AUC as compared to morphine alone. The co-administration of gabapentin with analgesic doses of 1 and 3 mg/kg morphine had also increased significantly AUC. Therefore gabapentin enhanced the antinociceptive effect of both analgesic and subanalgesic doses of morphine in a dose dependent manner. In conclusion co-administration of gabapentin with low doses of morphine produced therapeutic analgesia which could have important clinical application.
authors.affiliation: Physiology and Pharmacology Department, Kerman University of Medical Science, Kerman, Iran. manzume@yahoo.com
authors.forename: Manzumeh-Shamsi
authors.initials: MS
authors.lastname: Meymandi
authors.forename: Gholamreza
authors.initials: G
authors.lastname: Sepehri
authors.forename: Mina
authors.initials: M
authors.lastname: Mobasher
mesh_terms: D000588:Amines / Q000627:therapeutic use*; D000701:Analgesics, Opioid / Q000627:therapeutic use*; D000818:Animals; D019540:Area Under Curve; D003509:Cyclohexanecarboxylic Acids / Q000627:therapeutic use*; D004195:Disease Models, Animal; D004357:Drug Synergism; D000077206:Gabapentin; D008297:Male; D009020:Morphine / Q000627:therapeutic use*; D010146:Pain / Q000188:drug therapy*; D051381:Rats; D017208:Rats, Wistar; D005680:gamma-Aminobutyric Acid / Q000627:therapeutic use*
chemical_list: D000588:Amines; D000701:Analgesics, Opioid; D003509:Cyclohexanecarboxylic Acids; D005680:gamma-Aminobutyric Acid; D000077206:Gabapentin; D009020:Morphine