Analgesic Effects of Vilazodone, Indatraline, and Talsupram in a Rat Model of Neuropathic Pain

Objectives: Drugs that inhibit the reuptake of serotonin, norepinephrine, and/or dopamine are widely used for treating depressive disorders and have emerged as effective drugs for neuropathic pain. They have no substantial anti-nociceptive effects but are considered, with gabapentin/pregabalin, first-line drugs for neuropathic pain.

Materials and methods: In this study, three different antidepressant agents were used in different doses to investigate their anti-hyperalgesic effects in rat models of neuropathic pain using hot plate and tail flick methods. They have different mechanisms of action; vilazodone hydrochloride is a selective serotonin inhibitor and a 5-HT_1A partial agonist; talsupram hydrochloride is a selective noradrenaline inhibitor, and it has a high affinity for noradrenaline transporter (NET), whereas indatraline hydrochloride is a triple reuptake inhibitor that inhibits transporters for 5-HT (SERT), dopamine (DAT), and NET.

Results: All the drugs used in the experiment were found to have an anti-hyperalgesic effect in both tests compared to the sham group. When anti-hyperalgesic effects of the three agents were compared to each other, it was found that talsupram hydrochloride was significantly more effective than the two other drugs in hot plate test. However, there was no statistically significant difference in the tail flick test. Indatraline hydrochloride was more effective than vilazodone hydrochloride at the same doses in the tail flick test.

Conclusion: Our data suggest that three drugs are effective analgesics in rat models of neuropathic pain and inhibition of noradrenaline reuptake represents the cornerstone of analgesic mechanisms of effective antidepressants.

Neuropathic pain; anti-hyperalgesic; antidepressant; hot plate; indatraline; sciatic nerve ligation; tail flick; talsupram; vilazodone.