Pain, cancer, fibromyalgia and gastrointestinal disorders

Daytime sleepiness is very frequent in chronic pain sufferers and it is underpinned by disrupted nocturnal sleep patterns as well as by pain medications. There is emerging evidence that sleep disorders and daytime sleepiness are clinically relevant with respect to the quality of life in cancer patients. To distinguish daytime sleepiness from fatigue may be challenging in these conditions so that a comprehensive approach is advisable. Disrupted nocturnal sleep and daytime sleepiness are reportedly frequent in gastrointestinal disorders such as irritable bowel syndrome (IBS) and in cirrhosis. Daytime sleepiness has recently been reported to be associated with hepatic encephalopathy in cirrhotics. As far as the management of daytime sleepiness in chronic pain, cancer and gastrointestinal disorders is concerned, both pharmacological and behavioural treatments should be taken into account with the main goal being to improve nocturnal sleep quality. The Z-drugs and short half-life benzodiazepines proved to be effective in improving sleep continuity and stability in these patients. Activating drugs were also reportedly of use and appropriate to increase daytime alertness. Finally, specific treatments for the basic pathology and for comorbid sleep disorders such as sleep disordered breathing and Restless Legs Syndrome should be done.