Comparison of the anti‐allodynic effects of gabapentin, morphine and N‐palmitoylethanolamide in rats with chronic constriction of the sciatic nerve

Abstract

Neuropathic pain (NP) is a chronic disorder with a complex and multifactorial etiology. The NP prevalence constitute a significant health problem worldwide. Among the first choice drugs used for NP treatment is gabapentin (GBP), an antiepileptic drug and morphine (MOR), a prototype of analgesic opioid drug. Moreover, it has recently described the antinociceptive effects of N‐palmitoylethanolamide (PEA) on inflammatory pain.ObjectiveTo evaluate and compare the anti‐allodynic effects of GBP, MOR and PEA in rats with chronic constriction of the sciatic nerve (CCI model).MethodsThe anti‐allodynic effects of GBP (3.16–177.83 mg/Kg, p.o.), MOR (0.010–3.16 mg/Kg, s.c.) and PEA (3.16–10.00 mg/Kg, p.o.) were determined after single‐doses, using could allodynia test in the CCI model. Evaluations were done until 10 days post‐surgery at 30, 60, 90, 120 and 180 minutes after drugs administration.ResultIt was found that GBP, MOR and PEA showed anti‐allodynic effects in rats with NP induced by CCI. PEA achieved the same anti‐allodynic efficacy as the control group (GBP) and similar to the maximum efficacy achieved by MOR (p>0.05). The analysis of pharmacological potency demonstrated that: MOR (ED50 = 0.047 mg/Kg) was 28 time more potent than PEA (ED50 (1.319 mg/Kg), but PEA was 78 time more potent than GBP (ED50 = 103.3 mg/Kg).ConclusionsThese results demonstrate that PEA have anti‐allodynic effect similar to MOR and GBP, and also that PEA is more potent than GBP in rats with NP induced by CCI.Support or Funding InformationDepartment of Pharmacobiology, Cinvestav‐Unidad Coapa, C.P. 14330, Tlálpan, Mexico City, Mexico.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.