Premazepam is a pyrrolodiazepine derivative patented by Gruppi Lepetit S.p.A. as a muscle relaxant. Premazepam is a partial agonist of benzodiazepine receptors and was shown in 1984 to possess both anxiolytic and sedative properties in humans. Premazepam had a different EEG profile from diazepam, producing slower and less fast wave activity. In the single dose study, its effects were similar to diazepam for sedative action and most of the psychological tests, with a tendency towards greater psychomotor impairment. In the repeated dose study, however, premazepam caused less sedation and also tended to produce less psychomotor impairment.