Adherence monitoring and drug surveillance in chronic opioid therapy.

Monitoring adherence with chronic opioid therapies is a critical yet often difficult task. Because chronic opioid therapy is often fraught with complex pharmacological, psychological, social, and legal issues, its application is often controversial or altogether avoided. Improved drug monitoring and surveillance may help reduce some of the reluctance to use chronic opioid therapy in patients with chronic pain states. We review the literature on patient adherence/compliance with chronic administration of opioids as well as novel methods by which adherence with opioid therapy can be measured.