Manzumeh -Shamsi Meimandi
Department of Physiology and Pharmacology, Kerman Neuroscience Research Center, Kerman University of Medical Sciences, Iran
Mina -Mobasher
Department of Physiology and Pharmacology, Kerman Neuroscience Research Center, Kerman University of Medical Sciences, Iran
GholamReza -Sepehri
Department of Physiology and Pharmacology, Kerman Neuroscience Research Center, Kerman University of Medical Sciences, Iran
Ashrafganjooei Narges
Department of Physiology and Pharmacology, Kerman Neuroscience Research Center, Kerman University of Medical Sciences, Iran
ABSTRACT
This study was performed to evaluate the role of gabapentin co-administration in morphine antinociception and withdrawal effect. Four groups of male rats were examined for latency time using tail flick test; control, morphine (M), gabapentin (GB) and gabapentin-morphine (GB-M) treated groups. Rats received morphine (10 mg kg -1, s.c.) or gabapentin (75 mg kg -1, i.p.) or both of them twice a day for 9 days. Control rats received normal saline as schedule time. Latency time was recorded 3 times (5 min of interval) before drug injection and in 60, 65 and 70 min after drug injection in days 1, 3, 5, 7 and 9 by tail flick test. Percentage of Maximal Possible Effect (%MPE) as antinociceptive effect was calculated for all groups. On 9th day, rats were challenged for withdrawal signs by administration of naloxone (2 mg kg -1, i.p.). Analysis of variance showed no significant difference of %MPE in control and GB groups while in M and GB-M groups the %MPE was changed significantly during the days of study. Gabapentin had no analgesic effect while morphine and gabapentin-morphine had significant analgesic effect compared to control. %MPE of GB-M treated rats was significantly higher than M in days 5, 7 and 9. Also this study showed that pre-treatment with gabapentin reduced most of the opioid withdrawal signs including jumping, weight loss and fore paw tremor. The mechanism(s) by which gabapentin enhances the analgesic effect of chronic use of morphine and attenuate opioid withdrawal signs remain to be establish.
PDF References
How to cite this article
Manzumeh -Shamsi Meimandi, Mina -Mobasher, GholamReza -Sepehri and Ashrafganjooei Narges, 2005. Gabapentin Increases Analgesic Effect of Chronic Use of Morphine while Decreases Withdrawal Signs. International Journal of Pharmacology, 1: 161-166.
DOI: 10.3923/ijp.2005.161.166
URL: https://scialert.net/abstract/?doi=ijp.2005.161.166
DOI: 10.3923/ijp.2005.161.166
URL: https://scialert.net/abstract/?doi=ijp.2005.161.166
REFERENCES
- Eckhardt, K., S. Ammon, U. Hofman, A. Riebe, N. Gugeler and G. Mikus, 2000. Gabapentin enhances the analgesic effect of morphine in healthy volunteers. Anesth. Analg., 91: 185-191.
PubMedDirect Link - Trujillo, K.A. and H. Akil, 1991. Inhibition of morphine tolerance and dependence by the NMDA receptor antagonist MK-801. Science, 251: 85-87.
CrossRefDirect Link - Rose, M.A. and P.C.A. Kam, 2002. Gabapentin: Pharmacology and its use in pain management. Anaesthesia, 57: 451-562.
CrossRefPubMedDirect Link - Hwang, J.H. and T.L. Yaksh, 1997. Effect of subarachnoid gabapentin on tactile-evoked allodynia in a surgically induced neuropathic pain model in the rat. Regional Anesthesia Pain Med. 22: 249-256.
Direct Link - Chizh, B.A., M. Scheede and H. Schlutz, 2000. Antinociception and (R,S)-α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid and antagonism by gabapentin in rat spinal cord in vivo. Naunyn Schmiedeberg's Arch. Pharmacol., 362: 197-200.
CrossRefDirect Link