In patients with psoriasis, oral simvastatin combined with narrowband ultraviolet B phototherapy is not linked with additional beneficial effects. 

A randomized controlled trial determined the efficacy and safety of adding simvastatin to narrowband ultraviolet B (NB-UVB) phototherapy for the management of psoriasis.

This single-center, parallel-group, double-blind, placebo-controlled study recruited 48 people with moderate to severe plaque-type psoriasis who underwent NB-UVB phototherapy. Participants were randomly assigned to receive oral simvastatin [40 mg (two 20 mg tablets together) once a day] or placebo tablet once a day for twelve weeks, together with NB-UVB three times per week for each group. Using Dermatology Life and Quality Index (DLQI) and Psoriasis Area and Severity Index (PASI), an assessment of psoriasis severity was done.

In comparison with the baseline, a considerable decrease in PASI score was noted in both simvastatin and placebo groups after six and twelve weeks. No profound differences in decreasing PASI score and DLQI between the groups were noted at the 6th or 12th week.

Furthermore, DLQI substantially dropped in the placebo group in the 12th week. Contrary to the previous studies, no additional effects were reported for the combination of oral simvastatin and NB-UVB to treat psoriasis. In terms of improvement in quality of life, a non-significant inter-group difference was witnessed.

No substantial differences in PASI and DLQI scores were noted in people receiving NB-UVB phototherapy + simvastatin compared with people receiving NB-UVB phototherapy + placebo.