The effects of medication on sleep and wakefulness

Item does not contain fulltextThis chapter summarises the most important principles of sleep physiology and pharmacology, which hopefully will help the clinician to understand how sleep and wakefulness are affected not only by neurological disorders, but also by their medical treatment. The bulk of current hypnotic medication, including benzodiazepines, consists of compounds facilitating GABA-ergic transmission. The chapter presents the most relevant neuropharmacological systems, together with the routinely used medications that can have an impact on the sleep-wake cycle. Sleep factors such as adenosine build up with the amount of waking and physical activity. Serotonergic neurons, concentrated in the brainstem dorsal raphe nuclei, discharge maximally during waking, decrease their discharge during slow wave non-REM sleep (SWS) and virtually cease firing during REM sleep, suggesting that the highest extracellular 5-hydroxytryptamine (5-HT) levels should be found during waking. The chapter focuses on excessive sleepiness, significant insomnia and abnormal dream or nightmare activity at dose levels considered therapeutic