Venlafaxine hydrochloride (Wy 45030 hydrochloride) is a cyclohexanol and phenylethylamine derivative functioning as a serotonin and noradrenaline reuptake inhibitor (SNRI) used as an antidepressive agent.

In mice, the analgesic effect induced by Venlafaxine is significantly inhibited by naloxone, nor-BNI, and naltrexone indol, indicating involvement of kappa (κ-) and delta (δ-) opioid mechanisms, but not by β-FNA or naloxazone. In fully developed neuropathic rats, Venlafaxine reverses hyperalgesia. Venlafaxine demonstrates a dose-dependent analgesic effect with an ED50 of 46.7 mg/kg in mice.

Venlafaxine exhibits lower potential for inhibiting the metabolism of CYP2D6 substrates compared to widely used SSRIs such as desipramine and imipramine and can also inhibit the metabolism of several other major human hepatic P450 substrate enzymes. It inhibits the binding to human noradrenaline and serotonin transporters with K(i) values of 2480 nM and 82 nM, respectively. Furthermore, venlafaxine blocks p-chloroamphetamine and 6-hydroxydopamine-induced monoamine depletion with ED(50) values of 5.9 mg/kg and 94 mg/kg.