Objective: To evaluate the efficacy and safety of combination therapy with acitretin and pioglitazone hydrochloride in patients with moderate to severe chronic plaque-type psoriasis.

Design: Randomized, double-blind, placebo-controlled clinical trial.

Setting: A tertiary care referral hospital. Patients The study included patients of either sex (age range, 18-65 years) with moderate to severe chronic plaque-type psoriasis. Patients were excluded if they were of child-bearing potential or if they had impaired liver or renal function, hyperlipidemia, diabetes mellitus, coronary artery disease, or a body mass index greater than 30 (calculated as weight in kilograms divided by height in meters squared). Of the 62 patients screened, 41 were randomly assigned to 2 groups: 22 to an acitretin (25 mg) plus placebo group and 19 to an acitretin (25 mg) plus pioglitazone hydrochloride (15 mg) group. Main Outcome Measure Change in Psoriasis Area and Severity Index score between the 2 groups from baseline to 12 weeks.

Results: After 12 weeks of therapy, the percentage of reduction in the Psoriasis Area and Severity Index score was 64.2% in the acitretin plus pioglitazone group and 51.7% in the acitretin plus placebo group. The majority of the adverse events were mild to moderate except for 1 possibly unrelated episode of acute myocardial infarction in a 49-year-old woman in the acitretin plus placebo group.

Conclusions: Pioglitazone has a potential beneficial antipsoriatic effect and may provide a convenient, efficacious, and relatively safe option to combine with acitretin, although further studies are needed. Trial Registration clinicaltrials.gov Identifier: NCT00395941.