Pharmacological studies of the analgesic effect of antidepressants.
Explore the source record for details and available documents.
Analgesics↗
Biomedical subjects
D Ardid
Publications and source records attributed to D Ardid.
Comparative effects of different uptake inhibitor antidepressants in two pain tests in mice.
The purpose of this study was to compare the analgesic effect of acute injections (1.25 and 20 mg/kg, ip) of several antidepressants with different effects on monoamine reuptake, on two pain tests in mice (hot-plate and phenylbenzoquinone-induced abdominal writhes). Serotonergic inhibitors (citalopram, fluvoxamine and clomipramine) were more effective in the hot-plate test whereas noradrenaline reuptake inhibitors (desipramine and maprotilline) were more effective in the writhing test. The mixed antidepressants (amitriptyline and to a lesser degree trimipramine) were more effective in the two tests than the other antidepressant drugs. Changes in motor activity of clomipramine and amitriptyline could not account for the modifications of pain threshold. Amineptine (a dopamine reuptake inhibitor) failed to induce any antinociceptive effect in the hot-plate test and was hyperalgesic in the writhing test, which could be explained by an increased motor activity. These findings indicate that the antinociceptive potency of reuptake inhibitors varies according to their monoamine specificity and the nature of stimuli. They would suggest that the preferential choice of serotonergic antidepressants in the management of chronic pain is arguable.
Animals↗
Long-lasting antinociceptive effect of RC-160, a somatostatin analog, in mice and rats.
The effect of RC-160 (D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Trp-NH2) was studied in mice by means of the hot plate test and in rats with the tail flick test. In mice, 512 micrograms/kg (s.c.) induced an antinociceptive effect maximal (+88 +/- 17%) at the 6th hour after injection but still significant at the 24th hour; 16 micrograms/kg (s.c.) was active for 3 h; 64, 256 and 1024 micrograms/kg were active 30 min, 3 and 24 h after injection. The effects of these last three doses were not different. The antinociceptive action was as high at 24 h as at 3 h (e.g. for 512 micrograms/kg, 44 +/- 9% and 51 +/- 12%, respectively); 48 h after injection the scores of the treated groups were not different from the score for saline treatment in the tail flick test, 512 micrograms/kg induced a significant antinociceptive effect for 12 h (maximal at the 3rd hour: +60%). No behavioral changes, and particularly no motor activity modifications were observed.
Amino Acid Sequence↗
Evidence for a central but not a peripheral analgesic effect of clomipramine in rats.
The effect of clomipramine (CMI), a tricyclic antidepressant, was studied on an acute inflammatory pain model in an attempt to understand its potential antinociceptive activity, the involvement of a central and/or peripheral component and its influence on the inflammatory process. When administered (i.v.) before the inflammatory agent, carrageenan (CAR), CMI (0.125, 0.25 and 0.5 mg/kg) completely prevented the development of the hyperalgesia for 70-120 min according to the doses. This antinociceptive effect was suppressed by naloxone (100 micrograms/kg i.v.) for 65 min. Neither higher doses (1, 2 and 20 mg/kg, i.v.) nor CMI injected into the inflamed paw (15 min before CAR) modified pain thresholds. Moreover, CMI (0.5 and 2 mg/kg, i.v.) administered 15 min before CAR markedly increased the volume of the CAR-induced oedema. These results (1) demonstrate an opioid-dependent antinociceptive effect of CMI on this model, the doses used being lower than those active in thermal or electrical tests, and (2) tend to exclude a peripheral mechanism and an NSAID-like anti-inflammatory activity suggested by previous in vitro studies.
Analgesics↗