adalimumab (GI indication)

Brand: Humira

⚠ BBW Prototype: infliximab
Drug Class: TNF-alpha inhibitor
Drug Family: biologic DMARD
Subclass: fully human anti-TNF monoclonal antibody
Organ Systems: gastrointestinalimmunology

Mechanism of Action

Fully human monoclonal IgG1 antibody that binds both soluble and membrane-bound TNF-alpha, neutralizing its pro-inflammatory signaling, reducing cytokine-driven inflammation in the intestinal mucosa, and inducing apoptosis of activated T-lymphocytes through transmembrane TNF binding.

TNF-alpha (soluble and transmembrane)

Indications

  • moderate to severely active Crohn's disease
  • ulcerative colitis
  • rheumatoid arthritis
  • psoriatic arthritis
  • ankylosing spondylitis
  • plaque psoriasis
  • juvenile idiopathic arthritis

Contraindications

  • active TB or other serious infections
  • sepsis
  • hypersensitivity to adalimumab

Adverse Effects

Common

  • injection site reactions
  • upper respiratory infections
  • headache
  • nausea

Serious

  • serious bacterial, viral, fungal opportunistic infections
  • TB reactivation
  • malignancy (lymphoma, especially hepatosplenic T-cell lymphoma)
  • demyelinating disease
  • CHF worsening (doses >5 mg/kg IV)
  • lupus-like syndrome

Pharmacokinetics (ADME)

Absorption subcutaneous injection; bioavailability ~64%
Distribution Vd ~5–6 L; primarily intravascular
Metabolism proteolytic catabolism
Excretion proteolytic degradation
Half-life ~2 weeks
Onset weeks (clinical response in 4–12 weeks)
Peak 131 hours post-SC injection
Duration biweekly SC dosing
Protein Binding not applicable
Vd 5–6 L

Drug Interactions

Drug / Agent Mechanism Severity
live vaccines increased risk of infection from live vaccines during immunosuppression major
abatacept or anakinra additive immunosuppression with increased serious infection risk; generally avoid combination major
methotrexate reduces immunogenicity/ADA formation, increasing drug levels; used therapeutically beneficial

Nursing Considerations

  1. Screen for latent TB with TST or IGRA before starting; treat latent TB for at least 1 month before initiating adalimumab.
  2. Teach patients subcutaneous self-injection technique; auto-injector pens require refrigeration at 2–8°C; allow to warm to room temperature before injection.
  3. Monitor for signs of infection at every visit; hold adalimumab for serious active infections and do not restart until infection is resolved.
  4. Inform patients that live vaccines must be avoided; ensure completion of recommended vaccinations (including herpes zoster and pneumococcal vaccines) before starting therapy.

Clinical Pearls

  • Adalimumab is the first fully human anti-TNF antibody, reducing the risk of immunogenicity compared to chimeric antibodies like infliximab; however, combination with immunomodulators (azathioprine, methotrexate) further reduces antibody formation.
  • The combination of adalimumab plus an immunomodulator (e.g., azathioprine) is more effective than either agent alone for maintaining IBD remission.

Safety Profile

Pregnancy avoid
Lactation use-with-caution
Renal Adjustment Not required
Hepatic Adjustment Not required
TDM Not required