Management of insomnia in patients with chronic pain conditions

The management of insomnia in patients experiencing chronic pain requires careful evaluation, good diagnostic skills, familiarity with cognitive-behavioural interventions and a sound knowledge of pharmacological treatments. Sleep disorders are characterised by a circular interrelationship with chronic pain such that pain leads to sleep disorders and sleep disorders increase the perception of pain. Sleep disorders in individuals with chronic pain remain under-reported, under-diagnosed and under-treated, which may lead - together with the individual's emotional, cognitive and behavioural maladaptive responses - to the frequent development of chronic sleep disorders. The moderately positive relationship between pain severity and sleep complaints, and the specificity of pain-related arousal and mediating variables such as depression, illustrate that insomnia in relation to chronic pain is multifaceted and poorly understood. This may explain the limited success of the available treatments. This article discusses the evaluation of patients with chronic pain and insomnia and the available pharmacological and nonpharmacological interventions to manage the sleep disorder. Non-pharmacological interventions should not be considered as single interventions, but in association with one another. Some non-pharmacological interventions especially the cognitive and behavioural approaches, can be easily implemented in general practice (e.g. stimulus control, sleep restriction, imagery training and progressive muscle relaxation). Hypnotics are routinely prescribed in the medically ill, regardless of their adverse effects; however, their long-term efficacy is not supported by robust evidence. Antidepressants provide an interesting alternative to hypnotics, since they can improve pain perception as well as sleep disorders in selected patients. Sedative antipsy-chotics can be considered for sleep disturbances in those patients exhibiting psychotic features, or for those with contraindications to benzodiazepines. Low doses of sedative antipsychotics may improve chronic insomnia in the elderly. However, no intervention is likely to be effective unless a good physician-patient relationship is developed.