Sulpiride and paroxetine in the treatment of chronic tension-type headache. An explanatory double-blind trial.

Drugs influencing monoaminergic pathways are of potential use in the treatment of pain. A serotonin re-uptake inhibitor, paroxetine (20-30 mg daily), and a dopamine antagonist, sulpiride (200-400 mg daily) were compared in a randomized, double-blind, response-conditional cross-over pilot study in 50 non-depressed patients with chronic tension-type headache. Headache was scored daily on a 5-point verbal scale during 4-weeks baseline and during 8 weeks of treatment for each drug. A 5-point 'Global' assessment was obtained for each drug. In both treatment groups headache score decreased compared to baseline. Group comparison of 24 patients first treated with paroxetine and 24 patients first treated with sulpiride showed a non-significant trend in favor of sulpiride by 'Global' evaluation and by evaluation of the available diary records (18 paroxetine-treated and 19 sulpiride-treated). Cross-over analysis of 'Global' records from 20 patients treated with paroxetine followed by sulpiride and 17 patients treated in the reverse order showed better relief from sulpiride compared to paroxetine in patients having tested both drugs (P = .03). A similar difference was reflected in available headache scores (13 and 10 patients respectively; P = .03). Predominant side effects were sedation and depression, for paroxetine also nausea and head pain. None of the drugs improved headache more than one score-point on average. A placebo controlled trial of sulpiride may be warranted.