Firth H, Lewis S A, Ogunremi O O, Oswald I
Br J Pharmacol. 1970 Jun;39(2):462-3. doi: 10.1111/j.1476-5381.1970.tb12909.x.
In contrast to other amphetamine derivatives, fenfluramine (40 mg) and 780 SE (300 mg) had no effect on the rapid eye movement (REM) phase of sleep. Like other amphetamines they disturbed sleep, increasing the number of shifts to stage 1 (drowsiness) and stage W (arousal).