PEARLS 118, October 2008, written by Brian R McAvoy

Clinical question
How effective are antipsychotics for acute and chronic pain in adults?

Bottom line
The review suggests that antipsychotics may be useful as addon therapy for acute and chronic pain. Five of 11 trials showed beneficial effects of antipsychotics in the treatment of acute and chronic pain. Quantitative analysis showed a significant reduction of mean pain intensity after administration of the antipsychotic compared to placebo or another active compound.

Caveat
Results for antipsychotics in the treatment of different painful conditions were mixed, and most sample sizes in the reviewed trials were small (only one trial included more than 200 participants). Any benefits of antipsychotics have to be weighed up against extrapyramidal and sedating side effects.

Context
Antipsychotics (also called narcoleptics) have been used in different pain states, eg, chronic headache, fibromyalgia, low back pain, cancer pain, post-herpetic neuralgia and diabetic neuropathia.They are usually prescribed as add-on therapy to other analgesics.The antipsychotics trialled included tricyclics, butyrophenones and benzamides.

Cochrane Systematic Review
Seidel S et al.Antipsychotics for acute and chronic pain in adults. Cochrane Reviews 2008, Issue 4. Article No. CD004844. DOI: 10.1002/14651858. CD004844.pub2. This review contains 11 trials involving 770 participants.