Old drug--new indication. Rifampicin in psoriasis

The efficacy of traditional systemic therapies for psoriasis is limited by various side effects, toxicity, drug-drug interactions, and the need for frequent laboratory monitoring. In animal models, rifampicin causes immunosuppression and in conventional doses it suppresses the T-cell function.

To show that rifampicin has a therapeutic effect in eruptive psoriasis and to try to explain its mode of action.

A total of 76 patients (34 men and 42 women, aged between 12 and 68 years) with eruptive psoriasis were enrolled in the study. They were divided into two groups according to the evidence of a concomitant streptococcal infection. Rifampicin was administered orally in a 600 mg daily dosage for at least 60 days. Only emollients were given for topical therapy.

A statistical (chi-squared test) analysis was done and it could be concluded that improvement in the two groups was statistically indistinguishable (p = 0.892), while comparison with the control group showed a significant difference (p = 0.00082).

The results express that there is no statistically significant difference between the treating groups and the effect of rifampicin could not be related only to its antimicrobial properties. Its therapeutic effect most probably is due to its immunosuppressive properties.