BREAKTHROUGH PAIN IN CANCER-PATIENTS - CHARACTERISTICS, PREVALENCE, AND TREATMENT

''Breakthrough pain'' is a common clinical term that has not been conc lusively defined or described. Breakthrough pain is a transitory flare of pain experienced when baseline pain has been reduced to a mild or moderate level. Breakthrough pain may be characterized by its relation ship to a fixed around-the-clock (ATC) opioid dose, rapid onset and sh ort duration, precipitating events, predictability: pathophysiology (w ith nociceptive pain being most easily controlled), and etiology. The only prospective study of breakthrough pain conducted to date found a 63% prevalence of breakthrough pain in cancer patients referred to a p ain service. Although prevalence figures from other studies vary widel y, partly due to the populations chosen, all of the studies verify tha t breakthrough pain is a serious problem in cancer patients. In fact, several studies have listed incident pain, a subset of breakthrough pa in as a predictor of poor response to analgesic therapy. Breakthrough pain is currently managed with ornl or parenteral breakthrough pain me dications given in addition to the ATC analgesic regimen. The A TC dos age may also be increased until limited by side effects, Newer agents with a more rapid onset of analgesia and shorter duration of effect ma y help irt the management of breakthrough pain.