The wide variety of methotrexate dosing regimens for the treatment of atopic dermatitis: a systematic review

Background:Methotrexate is an off-label therapy for atopic dermatitis. A lack of consensus on dosing regimens poses a risk of underdosing and ineffective treatment or overdosing and increased risk of side effects. This systematic review summarizes the available evidence on dosing regimens.Materials and methods:A literature search was conducted, screening all randomized controlled trials (RCTs) and guidelines published up to 6 July 2023, in the MEDLINE, Embase, and Cochrane Library databases.Results:Five RCTs and 21 guidelines were included. RCTs compared methotrexate with other treatments rather than different methotrexate dosing regimens. The start and maintenance doses in RCTs varied between 7.5-15 mg/week and 14.5-25 mg/week, respectively. Despite varied dosing, all RCTs demonstrated efficacy in improving atopic dermatitis signs and symptoms. Guidelines exhibited substantial heterogeneity but predominantly proposed starting doses of 5-15 mg/week for adults and 10-15 mg/m2/week for children. Maintenance doses suggested were 7.5-25 mg/week for adults and 0.2-0.7 mg/kg/week for children. One guideline suggested a test dose and nearly half advised folic acid supplementation.Conclusion:This systematic review highlights the lack of methotrexate dosing guidelines for atopic dermatitis. It identifies commonly recommended and utilized dosing regimens, serving as a valuable resource for clinicians prescribing methotrexate off-label and providing input for an upcoming consensus study.

Methotrexate Dosing Regimen for Plaque-type Psoriasis: An Update of a Systematic Review

Background Methotrexate (MTX) is a systemic treatment for plaque-type psoriasis. At the time of approval, no dose-ranging studies were performed. Nowadays, a uniform dosing regimen is lacking. This might contribute to suboptimal treatment with the drug.Objective To summarize the literature involving the MTX dosing regimens in psoriasis patients.Methods In this SR, RCTs and documents with aggregated evidence (AgEv) on the MTX dosing regimen in psoriasis were summarized. All randomized controlled trials (RCTs) in which oral, subcutaneous or intramuscular MTX was used in patients with psoriasis and AgEv, were included. The MEDLINE, EMBASE and CENTRAL databases were searched up to June 20, 2022. This SR was registered in PROSPERO.Results Thirty-nine RCTs had a high risk of bias. Test dosages were given in only 3 RCTs. In the RCTs, MTX was usually prescribed in a start dose of 7.5 mg/week (n = 13). MTX was mostly given in a start dose of 15 mg/week, in the AgEv (n = 5). One guideline recommended a test dose, in other aggregated evidence a test dose was not mentioned or even discouraged.Conclusions There is a lack of high-quality evidence and available data for dosing MTX in psoriasis is heterogeneous.