Analgesic effects of antipsychotics in acute and chronic painful states

Antipsychotics are used in different chronic pain states (e.g. chronic headache, fibromyalgia and diabetic neuropathia). With atypical antipsychotics a new class of antipsychotics is available, with lesser extrapyramidal side effects and additional benefits. The review authors assessed the analgesic efficacy and adverse effects of antipsychotics (also known as neuroleptics) as reported in randomised controlled trials (RCTs) of adults prescribed any dose of oral antipsychotics for acute or chronic pain. Data from five of eleven included double-blind RCTs showed beneficial effects of antipsychotics in the treatment of acute and chronic pain. Quantitative analysis of these studies showed a significant reduction of mean pain intensity after administration of the antipsychotic compared to placebo or another active compound. Nevertheless, extrapyramidal and sedating side effects have to be considered before using antipsychotics for the treatment of painful conditions. Results for antipsychotics in the treatment of different painful conditions are mixed and most sample sizes in the reviewed double-blind RCTs are small. Further studies on atypical antipsychotics in larger double-blind placebo-controlled studies including standardised pain assessment are warranted.