Antinociceptive activity of some 1,4-substituted piperidine derivatives using tail flick method in mice

We have examined the potential antinociceptive effects of some piperidine derivatives (6a-f), using tail flick method in mice. Morphine was used as positive control drug. The results showed that compound 6b, having a bromine atom at 4 position, was the most active agent tested. The activity of this compound at 50 mg/kg was comparable to morphine (3 mg/kg). Based on the similarities between our compounds and meperidine like structures such as fentanyl, a group of mice was treated with naloxone before administration of 6f. It was concluded that opioid receptors could be the dominant mechanism for the antinociceptive activity of these types of structures. Electrostatic map, distance analysis and superimposition between fentanyl and compound 6b were also studied.   Key words: Piperidine derivatives, antinociceptive activity, tail flick.