Fumaric acid therapy in psoriasis: a double-blind comparison between fumaric acid compound therapy and monotherapy with dimethylfumaric acid ester.

In a 4-month double-blind study the effects of dimethylfumaric acid esters (DMFAE-EC) and DMFAE plus salts of monoethylfumaric acid esters (fumaric acid combination, FAC-EC) in enteric-coated tablets were compared in 22 respectively 23 patients with psoriasis. In both groups about 50% showed a considerable improvement, i.e. the initial score was more than halved. The therapeutic effects showed no significant differences in both groups with respect to the total psoriasis score or the different parameters. In the FAC-EC group the effects were obtained more rapidly. Most frequently observed side effects in both groups were flushings, stomachache and diarrhea. Due to these complaints 3 respectively 8 patients discontinued therapy. Eosinophilia, leukopenia and lymphopenia were the most frequently observed differences in lab tests. It was concluded that FAC-EC had no significantly better effect than monotherapy with DMFAE-EC. Moreover, enteric coating of the tablets did not prevent stomach complaints. Until more information has been obtained about the pharmacokinetics, the toxicity and optimal composition of the drug, the fumaric acid therapy in psoriasis should be seen as experimental.