Amfonelic acid: similarity to other dopamine agonists.

Rats were trained to discriminate between the stimulus properties of intraperitoneally administered 0.8 mg/kg amfonelic acid and its vehicle in a two-lever, food-motivated operant task. Once trained, rats showed a dose-related decrease in discriminative performance with lower amfonelic acid doses and analysis of the dose-response curve indicated an ED50 of 0.11 mg/kg. Administration of 0.08-0.6 mg/kg d-amphetamine produced a pattern of responding similar to that observed with amfonelic acid, with an ED50 of 0.10 mg/kg and a non-parallel dose-response curve. Likewise, the discriminative stimulus properties of amfonelic acid were shown to generalize to both d,l-cathinone and cocaine but not to apomorphine. The results suggest that amfonelic acid, as well as other non-amphetamine stimulants, acts by a different mechanism of action than does amphetamine and biochemical studies are reviewed to further evidence this observation.