Etanercept (Enbrel)

Biologicprescriptionsubcutaneous · inferred

Soluble TNF-receptor-p75/Fc fusion protein (decoy receptor) binding TNF-alpha and TNF-beta. Shorter-acting than mAb TNF inhibitors; 50 mg SC weekly (or 25 mg twice weekly). Approved for RA, psoriatic arthritis, ankylosing spondylitis, plaque psoriasis, JIA. Biphasic disposition with terminal half-life ~70-100h. SC bioavailability ~60%. Less immunogenic than full antibodies but still carries TB/serious infection risk.

Projected serum levels — 50 mg, once daily

Etanercept (Enbrel)
Etanercept (Enbrel) modeled serum levels, 50 mg once daily over 33 days Population-based pharmacokinetic estimate. Steady state reached after approximately 14 days. 0 125 250 375 500 Day 0 Day 8 Day 17 Day 25 Day 33 Time on a regular schedule ≈ steady state · day 14
Etanercept (Enbrel) modeled serum levels with a loading dose of 150 mg, then 50 mg once daily The first dose is larger so levels approach steady state faster. 0 125 250 375 500 Day 0 Day 8 Day 17 Day 25 Day 33 Time on a regular schedule

Maintenance schedule: 50 mg once daily (subcutaneous).

Loading schedule: 150 mg on day 1, then 50 mg once daily — reaching therapeutic levels sooner.

Modeled steady state after ~14 days: peak ≈ 295 mg, trough ≈ 291 mg body load. Population-based estimate over 33 days for a 50 mg dose at a 70 kg reference body mass — the interactive app scales curves to your doses, timing, and body mass.

Key facts

Category
Biologic
Route modeled
Subcutaneous
Model confidence
inferred
Half-life
4.3 days
Common dose
50 mg
Suggested maximum
50 mg/day
Reference dose range
25–50 mg (single dose)
Suggested cadence
once daily
Validated against
50 mg sc — Cmax 2.4 mg/L at 72 h

Documented interactions

  • watch
    Infliximab (Remicade) + Etanercept (Enbrel) Stacked effects

    Etanercept (Enbrel) and Infliximab (Remicade) both push the tnf alpha in the same direction.

Serum checks 1 modeled interaction pairings for etanercept (enbrel) across your whole stack — absorption conflicts, enzyme inhibition, and nutrient depletion included.

Research behind this entry

  1. Pharmacokinetics, pharmacodynamics, and safety of etanercept in patients with rheumatoid arthritis Korth-Bradley JM et al. · Clinical Pharmacology & Therapeutics, 2000 DOI

    Early clinical PK study establishing etanercept's terminal half-life (~70h), SC bioavailability, and dose-proportional exposure in RA.

  2. Clinical pharmacokinetics and pharmacodynamics of etanercept Zhou H · Journal of Clinical Pharmacology, 2005 DOI

    Review summarizing population PK, biphasic disposition, and target-mediated clearance contribution for etanercept.

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