Self-administration of the anti-inflammatory drug benzydamine in the rat: electrophysiological evidence of central glutamatergic mechanisms of action.

Benzydamine (BZY) is a non steroideal anti-inflammatory drug (NSAID) used for the topical treatment of inflammations of the oral (Tantum Verde®) and vaginal (Tantum Rosa®) mucosa. Virtually nothing is known about the central pharmacological actions of BZY. Yet, there are reports of voluntary systemic overdosage of BZY in drug addicts, resulting in a euphoric, hallucinatory state. In the present study, we investigated the reward proprieties of BZY in a rat self-administration paradigm. We found that BZY has a powerful reinforcing effect and that this effect is greatly facilitated in animals that had previously self-administered heroin and cocaine, indicating cross sensitization between BZY and other drugs of abuse. We then assessed the effect of BZY on cortico-accumbens glutamatergic transmission, using field recordings in rat parasagittal brain slices. BZY dose-dependently reduced fEPSP amplitude and paired pulse ratio, suggesting a presynaptic mechanism of action. Furthermore