Double-blind study of dothiepin versus placebo in the treatment of primary fibromyalgia syndrome.

A double-blind study comparing the efficacy and tolerability of dothiepin with that of placebo in the treatment of primary fibromyalgia syndrome was carried out. Dothiepin was shown to improve significantly the condition of patients with primary fibromyalgia syndrome and there was a significant difference between dothiepin and placebo in all the clinical variables measured. Only mild and transient side-effects were reported. Further controlled studies are required to define the effects of dothiepin on fibromyalgia.