Breakthrough pain in the management of chronic persistent pain syndromes.

Chronic pain results from tissue damage (nociceptive) or damage to the nerves or nervous system (neuropathic); it can stem from internal organs or cavity linings (visceral) or from the body's tissues (somatic). Mixed pain results from any number or combination of these types. Breakthrough pain (BTP) is a transitory, and often excruciating, flare that occurs against a background of chronic pain otherwise controlled by opioids. BTP is highly prevalent in patients with chronic pain of both cancer and noncancer origin, with episodes typically occurring several times daily that tend to peak within 10 to 30 minutes. Patients with BTP also endure heightened chronic pain, worsened physical function, and psychological distress. Several subtypes of BTP have been identified, including idiopathic, incident, and end-of-dose failure. The BTP Questionnaire is available to identify and characterize BTP and help determine the best treatment strategy for individual patients. This article reviews the etiology, prevalence, and characteristics of BTP along with assessment of patients and therapeutic strategies available to treat this condition.