ANTINOCICEPTIVE ACTIVITY OF NON-ANALGESIC AGENTS AND THEIR INTERACTIONS WITH TRAMADOL AND DICLOFENAC IN RATS

Abstract

Objective of this work is to study the antinociceptive activity of haloperidol, metoprolol, metoclopramide, venlafaxine and their interactions with tramadol and diclofenac. Antinociceptive action of haloperidol (1, 2 mg/kg), metoprolol (3, 5 mg/kg), metoclopramide (2, 5 mg/kg) and venlafaxine (5, 10 mg/kg) were studied in rats (tail flick and tail immersion tests). The sub-analgesic doses of haloperidol, metoprolol, metoclopramide and venlafaxine were combined with sub-analgesic doses of tramadol, diclofenac to further study their antinociceptive effects. The antinociceptive action of test drugs were found only at higher doses, for haloperidol (2 mg/kg), metoprolol (5 mg/kg), metoclopramide (5 mg/kg) and venlafaxine (10 mg/kg); that was statistically significant. When a sub-analgesic dose of test drugs were combined with sub-analgesic doses of tramadol, diclofenac, the combination resulted in a significant antinociceptive effect.Observations from our study indicate that various non-analgesic drugs may prove as alternative strategies for pain management in practice; possibly for adjuvant use.