[Insomnia: a persistent problem without optimal pharmacological approach].

Insomnia is a highly prevalent disorder in the Netherlands, with an estimated prevalence of 7-22%. The use of pharmacological interventions should be restricted, nevertheless, medications for insomnia are often prescribed. The use of off-label pharmacological interventions is increasing, although supporting evidence for these strategies is limited. In order to understand the use of certain on- and off-label strategies, we describe the pathophysiology of insomnia and the clinical pharmacology of various on- and off-label drugs.