Methotrexate (MTX) is the most commonly used systemic therapy for psoriasis. The drug is a folie acid antagonist and the main effect on psoriasis is thought to be inhibition of lymphatic cell proliferation (1). Due to its anti-inflammatory effect, MTX may also have a protective effect against cardiovascular disease (2,3). MTX is generally well tolerated, but common, minor adverse reactions are nausea, loss of appetite, and fatigue. Major toxicities include myelosuppression, hepatotoxicity, and pulmonary flbrosis (4).Although MTX has been used in the treatment of inflammatory disorders since the 1950s (5), there have been few evidence-based studies on MTX in the treatment of psoriasis. Results from three recent randomized controlled studies of patients with psoriasis showed that MTX was as effective as cyclosporin (6), or less effective than ciclosporin (7), and less effective than adalimumab, but more effective than placebo (8). In these studies Psoriasis Activity and Severity Index (PASI)-75 (75% improvement in PASI) for the patients treated with MTX was 60% at week 16 (6), 24% at week 12 (7), and 35.5% at week 16 (8), and rates of discontinuation of MTX therapy due to adverse reactions were 28% (6), 0% (7), and 5.5% (8), respectively.The main purpose of this study was to determine the reasons for discontinuation of MTX treatment in patients with psoriasis. Secondly, we wanted to discuss the potentially preventable or adjustable factors that might influence the specific reasons for discontinuation.
METHODSWe reviewed the records of all patients who were registered as having an International Classification of Disease (ICD-10) code of psoriasis in the years 1997-2007 at our Dermatological Department. The inclusion criteria were: diagnosis of psoriasis made by a dermatologist, minimum age of 18 years, treatment with MTX at any period between 1997 and 2007, and discontinued MTX treatment before the date of data collection. We excluded patients treated with MTX because of palmoplantar pustulosis, nail psoriasis, psoriasis arthritis, or as a supplement to infliximab treatment. The main reasons for discontinuation of MTX therapy were recorded together with patient-and treatment-related data.The data were evaluated using descriptive statistics.
RESULTSIn the period 1997-2007, a total of 2,221 patients with psoriasis were treated at our department. The inclusion criteria were met by 156 of these patients. Median duration of MTX therapy was 7.5 months (range 0.3-264 months), median accumulated MTX dose was 524 mg (range 15-16,925 mg), and at the end ofthe treatment median weekly MTX dose was 12.5 mg (range 2.5-30 mg). MTX was administered orally to 142 patients (91%) and 94 patients (60.3%) received folate supplementation. The most frequent main reason for discontinuation of MTX therapy was adverse reactions, which were reported in 89 patients (57%). Remission was the second most frequently reported main reason for discontinuation of MTX, followed by "lack of clinical response" and finally "non-drug-related reasons" (Tabl...
