Long-term use of opioid analgesics for the treatment of chronic pain of nonmalignant origin.

The use of long-term opioids (LTOs) to treat chronic pain of nonmalignant origin (CNMP) is controversial. Most physicians had felt there was essentially no role for LTOs in CNMP, but successful treatment outcomes have recently been reported. Tolerance, organ toxicity, or fear of addiction are not reasons to limit LTOs. The significant question is efficacy. Does LTO therapy improve pain and increase function with minimal side effects or risk? It is useful to divide chronic pain patients into three types. Type 1 patients are "typical" chronic pain patients with pain and disability far out of proportion to the peripheral stimulus. Psychological factors are significant. In this type of patient, opioids appear to do more harm than good. Type 2 patients have ongoing nociception and moderate refractory pain. Type 3 patients have refractory severe nociception or neuropathic pain. The latter types might be considered for LTOs. LTO use is appropriate for a very small, carefully selected group of patients.