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Methotrexate (Rheumatrex / Trexall)

Disease-Modifying Antirheumatic Drug (DMARD)prescriptionoral · inferred

Folate antagonist used at low weekly doses for rheumatoid arthritis, psoriasis, and other autoimmune conditions. Inhibits dihydrofolate reductase and has anti-inflammatory effects. Taken once weekly (not daily). Requires folic acid supplementation and monitoring of liver/blood counts.

Projected serum levels — 15 mg, weekly

Methotrexate (Rheumatrex / Trexall)
Methotrexate (Rheumatrex / Trexall) modeled serum levels, 15 mg weekly over 21 days Population-based pharmacokinetic estimate. Steady state reached after approximately 7 days. 0 2.5 5 7.5 10 Day 0 Day 5 Day 11 Day 16 Day 21 Time on a regular schedule ≈ steady state · day 7

Maintenance schedule: 15 mg weekly (oral).

Modeled steady state after ~7 days: peak ≈ 9.0 mg, trough ≈ 0.000 mg body load. Population-based estimate over 21 days for a 15 mg dose at a 70 kg reference body mass — the interactive app scales curves to your doses, timing, and body mass.

Key facts

Category
Disease-Modifying Antirheumatic Drug (DMARD)
Route modeled
Oral
Model confidence
inferred
Half-life
7 h
Common dose
15 mg
Suggested maximum
25 mg/day
Reference dose range
7.5–25 mg (single dose)
Suggested cadence
weekly
Validated against
15 mg oral — Cmax 0.15 mg/L at 1.2 h

Documented interactions

  • moderate
    Apigenin + Methotrexate (Rheumatrex / Trexall) Transporter inhibition

    Apigenin inhibitor of BCRP may alter Methotrexate (Rheumatrex / Trexall) absorption / distribution

  • moderate
    Fisetin + Methotrexate (Rheumatrex / Trexall) Transporter inhibition

    Fisetin inhibitor of BCRP may alter Methotrexate (Rheumatrex / Trexall) absorption / distribution

  • moderate
    Glecaprevir + Methotrexate (Rheumatrex / Trexall) Transporter inhibition

    Glecaprevir inhibitor of BCRP may alter Methotrexate (Rheumatrex / Trexall) absorption / distribution

  • moderate
    Pibrentasvir + Methotrexate (Rheumatrex / Trexall) Transporter inhibition

    Pibrentasvir inhibitor of BCRP may alter Methotrexate (Rheumatrex / Trexall) absorption / distribution

  • moderate
    Quercetin + Methotrexate (Rheumatrex / Trexall) Transporter inhibition

    Quercetin inhibitor of BCRP may alter Methotrexate (Rheumatrex / Trexall) absorption / distribution

  • moderate
    Ritonavir + Methotrexate (Rheumatrex / Trexall) Transporter inhibition

    Ritonavir inhibitor of BCRP may alter Methotrexate (Rheumatrex / Trexall) absorption / distribution

Serum checks 8 modeled interaction pairings for methotrexate (rheumatrex / trexall) across your whole stack — absorption conflicts, enzyme inhibition, and nutrient depletion included.

Research behind this entry

  1. Efficacy of low-dose methotrexate in rheumatoid arthritis Weinblatt ME et al. · New England Journal of Medicine, 1985 DOI

    Landmark double-blind crossover trial of 28 patients with refractory RA demonstrated oral methotrexate significantly reduced tender joints, morning stiffness, and disease activity versus placebo.

  2. Long-term prospective trial of low-dose methotrexate in rheumatoid arthritis Weinblatt ME et al. · Arthritis & Rheumatism, 1988 DOI

    Extended follow-up of RA patients on low-dose methotrexate showing sustained improvement in joint counts, global assessments, and ESR over years of therapy.

  3. Comparison of low-dose oral pulse methotrexate and placebo in the treatment of rheumatoid arthritis Williams HJ et al. · Arthritis & Rheumatism, 1985 DOI

    Multicenter controlled double-blind trial of 189 RA patients confirming low-dose pulse methotrexate produced significant improvement in all clinical variables versus placebo.

3 published studies referenced in the app, each with a plain-language summary.