clinical aspects of sleep disturbances and sleeping drugs complaints about sleep disturbances are a common everyday problem in the general practitioners surgery only a few patients need a thorough expert examination in a special sleep laboratory thanks to eeg which makes available a continuous record of uninterrupted sleep cycles knowledge of the physiology of sleep now includes important information about the normal circadian rhythm of waking and sleeping the alternation of rem and nonrem periods and the depth of the individual sleep cycles eeg results are also an important basis for checking the effect of sleeping drugs analysis of sleep disturbances is based on the formal distinction between hypersomnia and hyposomnia and parasomnia etiologically a distinction must be made between exogenic and endogenic sleep disturbances and attention given to the fact that disturbances of night sleep also affect vigilance on the following day these considerations are also important for the use of sleeping drugs whose halflife and biological effect allow a useful differentiation between substances giving impulses to sleep sleepinducing drugs and those enabling uninterrupted sleep during nighttime sleep disturbances combined with certain other symptoms belong to particular syndromes in which it may be necessary to use sleeping drugs but these should only be used in combination with other drugs in order to reduce the risk of side effects tolerance changes dependence and addiction with longterm treatment when a combination of different drugs is given interference through interaction with lipid or protein binding and induction or enzyme breakdown in the liver should be taken into account