Fenmetozole is an alpha-2 adrenergic receptor antagonist which was developed for the treatment of schizophrenic and/or depressed patients, however never reached the market. It was also shown that the drug may reduce symptoms of minimal brain dysfunction in children and antagonize the effect of barbiturates and ethanol.

Zetidoline (DL-308) is an antipsychotic drug with antidopaminergic properties. It is a dopamine D2 receptor antagonist. DL-308 displayed sedative properties, as indicated by the sedated appearance of the subjects, by a decrease in subjectively rated alertness and by an impairment of performance on psychomotor tests. DL-308 appeared to be a more potent sedative than thioridazine. DL-308 (10 mg) caused an increase in subjectivey rated sweating and objectively measured heart rate, suggesting a sympathomimetic property for the drug. DL-308 had effects consistent with an alpha-adrenolytic action; it caused miosis, hypotension and a decrease in salivation. DL-308 had little effect on the motor system, as indicated by conventional clinical neurological examination.

Fenmetozole is an alpha-2 adrenergic receptor antagonist which was developed for the treatment of schizophrenic and/or depressed patients, however never reached the market. It was also shown that the drug may reduce symptoms of minimal brain dysfunction in children and antagonize the effect of barbiturates and ethanol.