Morphine‐like insomnia from heroin in nondependent human addicts.

1 This study was performed because dose‐related effects of heroin on human sleep had not been described previously, and to discover if heroin produces a morphine‐like insomnia. 2 After three adaptation nights, the sleep of seven male nondependent opiate addicts was studied following i.m. doses of heroin (3, 6, 12 mg/70 kg), morphine (10, 20 mg/70 kg) or placebo at weekly intervals in a randomized double‐blind crossover design. 3 Heroin produces a dose‐related increase in wakefulness, drowsiness episodes, muscle tension, and shifts in sleep‐ waking states. 4 Heroin produces a dose‐related decrease in total sleep, sleep efficiency, delta sleep and REM sleep (REMS). 5 Heroin is about twice as potent as morphine in producing this type of insomnia. 6 'Morphine insomnia' appears to be a characteristic initial effect of several opioids, at least in nondependent opiate addicts, and might serve as a model insomnia for evaluation of hypnotics. 1981 The British Pharmacological Society