Considerable variation among Iranian dermatologists in the dosing and monitoring of methotrexate for treating psoriasis.

Background: Methotrexate (MTX) is a risky medication requiring careful attention to dosing and monitoring. Dosing and monitoring practices are not well characterized.

Aims: The aim of this study was to assess variation in the dosing and monitoring of methotrexate among Iranian dermatologists.

Methods: A questionnaire was administered to forty experts in psoriasis concerning the use of MTX.

Results: Among the 39 responding dermatologists (15 women, 24 men), 54% saw fewer than 10 psoriatic patients per week, 23% 10-20 patients, and 23% more than 20 patients. About half of the dermatologists treat their patients with an initial MTX dose of <7.5 mg/week (range 5-17.5 mg/week), an average dose of <10 mg/week (range 5-25 mg/week), and a maximum dose of <20 mg/week (range 7.550 – mg/week) with 71.8% prescribing the medication orally and 28.2% intramuscularly. Subcutaneous injection was preferred by none of the dermatologists as a usual route of administration. Nearly 5% of the dermatologists believe that liver biopsy should be performed prior to treatment with MTX in all patients, and another 5% consider this procedure prior to treatment only in patients with risk factors. About 44 and 33% of the dermatologists do the liver biopsy after 1.0-1.5 g and 3.54 g total cumulative doses, respectively.

Conclusion: After more than a half century, there are still noticeable controversies on the manner of using MTX in treating psoriasis among Iranian dermatologists. A national guideline may help standardize treatment practices.