The antinociceptive effect of fluvoxamine

The authors conducted a study in order to evaluate the antinociceptive effects of the serotonin-selective reuptake inhibitor (SSRI) antidepressant fluvoxamine and its interaction with various opioid receptor subtypes. Male ICR mice were tested with a hotplate analgesia meter. Fluvoxamine elicited antinociceptive effect in a dose-dependent manner following i.p., i.t. and i.c.v. injection. Naloxone 10 mg/kg s.c. did not abolish the fluvoxamine antinociceptive effect. At the next stage fluvoxamine was administered together with various agonists of opioid receptors. When administered together with opiates, fluvoxamine significantly potentiated analgesia at the K_j-opioid receptor subtype (P<.005) and to a lesser extent, at the μ-, δ-, and K₁-opioid receptors. We conclude that fluvoxamine alone induces an antinociceptive effect. This effect is mediated by a non-opioid mechanism of action. These results suggest a potential role for fluvoxamine in the management of pain when co-administered with opioids at low doses.