Comparison of methotrexate and azathioprine in the treatment of psoriasis: a randomized controlled trial

Background Treatment of psoriasis requires a safe and effective drug which can be used on long term basis. Azathioprine is one such agent which was used in the past but has not been tested recently.Patients and methods A randomized controlled trial was conducted at dermatology department, Combined Military Hospital, Kharian, to compare the efficacy and safety of azathioprine with that of methotrexate in patients with severe psoriasis requiring systemic therapy. Patients included in the study were randomized into two groups. Group A received tablet methotrexate 10 mg weekly for 8 weeks. Group B patients received tablet azathioprine in a dose of 1.5-3 mg/kg/day. In all the adult patients who were weighing more than 50 kg azathioprine was started at a dose of 50 mg tablet thrice daily for 8 weeks. PASI score was assessed at the start and end of treatment. Scores were compared in the two groups before and after and statistically analyzed using paired and independent sample t test.Results 50 patients entered the study. Results were stratified into excellent, good, and poor response, based on improvement in PASI scores. Excellent response was seen in 73% patients in group A and 27% patients in group B (p 0.5). Good response was seen in 45% patients in group A and 55% patients in group B (p 0.5). Poor response was seen in one patient in each group (p 0.5, paired sample t test).Conclusion Azathioprine is less effective in systemic treatment of psoriasis. Nevertheless it can be a useful alternative in selected patients