Besides the obvious physical and psychological aspects of dependency and addiction, is there any research documenting the effect of using long-term opioids (to treat chronic pain) on the body?
—Michelle Simpsom, MSN, APRN-BC, Leonard, Mich.

An excellent review of opioid research reveals that patients may experience hyperalgesia, a heightened sensitivity to painful stimuli, endocrine dysfunction, and reduced cellular immune response (Med Clin North Am. 2007;91:177-197). In one large study of more than 5,500 patients treated with long-term opioids for chronic non-cancer pain, the most commonly reported side effects were dry mouth (25%), nausea (21%), and constipation (15%).
—Virginia Joslin, PA-C, MPH, and Allan Platt PA-C, MMSc, instructor, Emory Physician Assistant Program, Emory University, Atlanta (117-1)