[What is certain in pain therapy? The analgesic potency of neuroleptics in the treatment of chronic pain. A metaanalysis]

Abstract

The wide variety of therapeutic effects make neuroleptics potent drugs in the treatment of pain. Until now there has been no proof of their analgesic potency; in spite of this fact, neuroleptics are used to treat chronic pain states on the assumption that they do have analgesic potency. A metaanalysis was performed and 48 publications reviewed. Thirty-four, the majority of the studies, are case reports, retrospective analyses or non-randomised cohort studies. Most of these reports attest to a positive effect. However, only ten out of fifteen studies with a higher statistical study power describe a possible analgesic effect. None of the studies could differentiate between the effects of analgesia and sedation of the drugs used. The metaanalysis provides no evidence of intrinsic analgesic properties of neuroleptics for their use as adjuvant analgesics.