[Drug treatment of CRPS].

The main symptoms of excruciating pain, trophic and inflammatory changes, as well as functional impairment of limbs are the hallmark of the complex regional pain syndrome (CRPS). While functional impairments have to be treated by physical and occupational therapy, the former three symptoms are amendable to drug treatment: antidepressants, antiepileptic drugs and opioids are the most important drug classes for alleviating neuropathic pain whereas acute nociceptive pain may be positively influenced by non-steroidal anti-inflammatory drugs and steroids. In addition, calcitonin and the biphosphonates inhibit osteoclasts and therefore loss of bone mass and may thus also reduce pain. The use of sympatholytic agents beyond locoregional anesthesia techniques (which are covered elsewhere in this issue) is not unequivocal. In general, the evidence level for treatment strategies specifically for the complex regional pain syndrome is very poor; most recommendations and algorithms rely on results derived from studies testing drugs against other conditions where chronic (neuropathic) pain is prevalent, like diabetic polyneuropathy or postherpetic neuralgia, or medications are used on the basis of pathomechanistic considerations.