Phase I study of a new antianxiety drug, buspirone

1. A phase I study of buspirone was conducted in 7 healthy male volunteers. 2. Diazepam was selected as the control drug and administered in equipotent doses to buspirone. Dosage was initiated at 2.5mg and doubled until a maximum dosage of 20mg was attained. Subsequently, 10mg was administered once a day for three consecutive days. 3. Clinico-pharmacologically both drugs produced sleepiness/drowsiness, but dizziness, light-headed feeling and feeling of drunkenness were marked only in the diazepam group. 4. No drug-related abnormalities were observed in clinical laboratory test values, endocrinological tests and ECG. 5. On the Uchida-Kraepelin test, no change with the control values was observed under buspirone but subjects administered diazepam exhibited marked deterioration during the latter half of the test. Moreover, in the tapping test, significant impairment was observed in the diazepam group whereas buspirone had no effect. 6. On the EEG some fast waves were observed with diazepam whereas buspirone exhibited slow waves.