Analgesia by nefopam: does it act through serotonin?

In an attempt to clarify the possible mode of action of nefopam, a new analgesic compound, the authors tested its effects on imipramine (IMI) binding to platelet membranes. The results showed that nefopam exerted a concentration-dependent inhibition of IMI binding, with a potency comparable to that of tricyclic antidepressants. This finding suggests a possible intervention of serotonergic mechanisms in nefopam-related analgesia.