Amisulpride in the treatment of fibromyalgia: an uncontrolled study

Some antipsychotics, including amisulpride, have shown to be effective in the treatment of various painful conditions, lessening pain as well as symptoms of anxiety and/or depression. In this open-label, 12-week study, we explored the efficacy and tolerability of amisulpride in patients with fibromyalgia. We recruited 40 patients, 1 male and 39 females, aged 46.2 ± 6.8 years, who met the ACR criteria for fibromyalgia and had a score equal to or greater than 4 in the pain severity item of the Fibromyalgia Impact Questionnaire (FIQ). Amisulpride was added to their current treatment regimen at an initial dose of 25 mg/day and titrated according to the clinical response and tolerability (mean final dose, 87.5 ± 41.3 mg/day). In the intent-to-treat analysis (i.e., all recruited patients), using a baseline-observation-carried-forward approach, the mean score in the FIQ decreased from 75.7 ± 10.6 to 73.2 ± 15.4, but this change was not statistically significant. Pain severity, as measured with the visual analogue scale from the FIQ, remained unchanged. Nonsignificant improvements were observed in depressive or anxiety symptoms using the Beck Depression Inventory and the State-Trait Anxiety Inventory, respectively. Twenty-six patients either withdrew from the study, mainly due to adverse reactions, or were lost to follow-up (n = 11, 27.5 %, for each category). Despite its promising results in some chronic painful conditions and in a related illness, such as chronic fatigue syndrome, amisulpride does not seem to provide any benefit to patients with fibromyalgia. Amisulpride was poorly tolerated by our participants.