Korean J Anesthesiol.  2004 Jan;46(1):91-95. 10.4097/kjae.2004.46.1.91.

The Effects of Gabapentin on Facial Formalin Test

• Kim CH
• Baik SW
• Kim HK
• Kwon JY
• Kim KH
• Choi SH

• KMID: 2237266
• DOI: http://doi.org/10.4097/kjae.2004.46.1.91

Abstract

BACKGROUND
Gabapentin is a novel anti-epileptic drug, which is used in clinical practice to treat epilepsy. This drug is also used as an analgesic in pain patients. The antinociceptive effect of this drug was assessed using the formalin test in the rat.
METHODS
In order to investigate the effects of gabapentin on the trigeminal nerve territory, we injected 0.5 % formalin into the upper lip. Adult, male, Sprague-Dawley rats received a 50mul subcutaneous injection of 5% formalin into one vibrissal pad and the consequent, facial grooming behavior was monitored. Consistent with previous investigations using the formalin model, animals exhibited biphasic nocifensive grooming (phase 1, 0-12 min; phase 2, 12-60 min).
RESULTS
The intraperitoneal administration gabapentin 5 minutes prior to the formalin injection led to a significant, dose-dependent reduction in grooming time during phase 2. In high doses, gabapentin also reduced the time of grooming during phase 1.
CONCLUSIONS
The Intraperitoneal injection of gabapentin has an analgesic effect in the facial formalin rat model and this analgesic effect increases dose-dependently.

Keyword

gabapentin; trigeminal nerve; facial formalin test

MeSH Terms

Adult
Animals
Epilepsy
Formaldehyde*
Grooming
Humans
Injections, Intraperitoneal
Injections, Subcutaneous
Lip
Male
Models, Animal
Pain Measurement*
Rats
Rats, Sprague-Dawley
Trigeminal Nerve
Formaldehyde