Benzodiazepines are the most frequently prescribed drugs in the Western world. About 3% of the adult Swiss population regularly use benzodiazepines for the treatment of anxiety states or for induction of sleep. All benzodiazepine agonists available exert qualitatively similar pharmacodynamic actions. They commonly activate central GABAergic neuroinhibition, thereby inducing anxiolysis, sedation/hypnosis, anticonvulsion and muscle relaxation. However, various derivatives differ in their physicochemical and pharmacokinetic properties such as lipophilicity, rate of gastrointestinal absorption, hepatic biotransformation and elimination half life. These differences among individual substances can be used clinically to optimize therapy for the individual patient. For example, the elimination half life greatly influences the frequency, intensity and type of adverse reactions such as hangover, rebound insomnia, development of tolerance and dependence as well as withdrawal symptoms. It is estimated that "low-dose dependency" develops in as many as 30 to 45% of chronically treated patients. Low-dose dependency is mainly characterized by the appearance of withdrawal symptoms after cessation of therapy. Since management of the withdrawal state is difficult and especially troublesome for the patient it is best to prevent the development of benzodiazepine dependence by prescribing these drugs less and restricting them to short-term use (7-14 days).