A repeated dose comparison of dichloralphenazone, flunitrazepam and amylobarbitone sodium on some aspects of sleep and early morning behaviour in normal subjects.

1 Seven normal subjects were given three different hypnotics (flunitrazepam 1 mg, amylobarbitone sodium 100 mg and dichloralphenazone 1300 mg) for four consecutive nights each. 2 All three substances improved subjective assessment of the ease of getting to sleep. Flunitrazepam was rated as better than eithr dichloralphenazone or amylobarbitone sodium in this respect. 3 The perceived quality of induced sleep was not altered by any of the preparations. 4 There was a disturbance of the subjective ratings of getting to sleep following cessation of treatment with dichloralphenazone, giving tentative support to the existence of a 'rebound' effect. 5 Dichloralphenazone produced an impairment in psychomotor performance as measured on a complex reaction time test following four nights medication with the drug.