Generic Name

Humira

Mechanism

• TNF‑α neutralization: Binds circulating soluble TNF‑α and cell‑surface TNF‑α, preventing interaction with TNF receptors (p55/p75).
• Receptor blockade: Inhibits downstream NF‑κB activation, cytokine production, and leukocyte recruitment, thereby reducing inflammation.
• Apoptosis modulation: Induces apoptosis of activated T cells and macrophages that express membrane‑bound TNF‑α.
• Clinical impact: Slows disease progression in rheumatoid arthritis (RA), psoriatic arthritis (PsA), ankylosing spondylitis (AS), plaque psoriasis, Crohn’s disease, ulcerative colitis, and non‑infectious uveitis.

Pharmacokinetics

Indications

• Rheumatoid arthritis – moderate‑to‑severe disease, active when methotrexate fails/ is contraindicated.
• Psoriatic arthritis – including peripheral arthritis, enthesitis, and dactylitis.
• Plaque psoriasis – moderate–severe using systemic therapy.
• Ankylosing spondylitis – active disease refractory or intolerant to NSAIDs/NSAIDs+TNF‑α inhibitors.
• Crohn’s disease – moderate‑to‑severe disease; can be a bridge to surgery.
• Ulcerative colitis – moderate‑to‑severe disease.
• Non‑infectious uveitis – active intermediate, posterior, or panuveitis.

> *Note:* While the above are label indications, off‑label uses include sarcoidosis, hidradenitis suppurativa, and systemic lupus erythematosus (under compassionate use).

Contraindications

• Active serious bacterial, viral, or fungal infections (e.g., tuberculosis, hepatitis B).
• Active latent TB – screen via IGRA or TST before initiation.
• Known hypersensitivity to adalimumab or murine proteins.
• Severe comorbidities: uncontrolled heart failure (NYHA III–IV), significant renal/hepatic impairment (elevated AST/ALT >5× ULN).
• Pregnancy & lactation – category C; avoid if possible; safe in lactation to a limited extent.
• Vaccinations – live‑attenuated vaccines contraindicated during therapy.
• Malignancy – pre‑existing malignancy is a precaution; prudent patient‑specific risk assessment.
• Reflux esophagitis, severe organ transplant – increased risk of reactivation of latent infections.

Dosing

• Rheumatoid arthritis (adult): 40 mg SC every 2 weeks (q2 wk) after initial 80 mg loading dose at week 0.
• Psoriatic arthritis & plaque psoriasis: 40 mg q2 wk; after 4 weeks, may titrate to 40 mg every 4 weeks if clinical response achieved.
• Crohn’s disease: 160 mg oral tablet (sustained‑release) at baseline, then 80 mg weekly for 4 weeks, followed by 40 mg biweekly.
• Ulcerative colitis & ankylosing spondylitis: 40 mg q2 wk.
• Uveitis: 20 mg weekly (~40 mg q2 wk) in pediatric patients; 40 mg q2 wk in adults.
• Subcutaneous technique: Inject into abdomen, thigh, or upper arm; rotate sites; saline‑irrigated needle (28‑30 G) or prefilled pen.
• Pediatric dosing (adults): Weight‑based: 0.8 mg/kg (up to max 40 mg) q2 wk.

> *Tip:* For patients who miss a dose, do not double‑dose; resume next scheduled dose or add 8 weeks if overdue.

Adverse Effects

Common (≥5 %):
• Injection site reaction (pain, erythema, swelling)
• Upper respiratory tract infections
• Headache
• Nausea

Serious (≥1 %):
• Opportunistic infections (TB reactivation, Pneumocystis jirovecii, histoplasmosis)
• Hepatitis B reactivation
• Malignancies (non‑melanoma skin, lymphoma)
• Demyelinating disorders (e.g., multiple sclerosis relapses)
• Lupus‑like syndrome (anti‑dsDNA antibodies, fever, rash)
• Severe hypersensitivity/anaphylaxis
• Neutropenia, thrombocytopenia

> *AE monitoring:* screen for TB/HBV prior to initiation; monitor CBC, LFTs, and symptoms of infection during therapy.

Monitoring

• Infection screening: TST/IGRA & chest X‑ray prior to first dose; HBV serology; HIV screen if indicated.
• Vaccinations: review schedule; avoid live vaccines; administer inactivated vaccines at least 2 weeks before initiating Humira.
• Laboratory labs:
• CBC, LFTs, and renal panels every 4–8 weeks for first 6 months, then annually.
• At any sign of infection or unexplained symptoms, repeat labs.
• Disease activity: Use DAS28 (RA), PASI (psoriasis), Mayo score (ulcerative colitis) at baseline and every 12 weeks.
• Imaging: Radiographs or MRI for progressive joint damage monitoring.
• Pregnancy/Lactation: Discuss contraception; counsel on risks.

Clinical Pearls

1. TB Kick‑off Screening: Use IGRA over TST when possible due to higher specificity in vaccinated individuals.

2. Combination Therapy Safety: Co‑administration with methotrexate reduces anti‑drug antibody formation, improving efficacy and durability.

3. Weight‑Based Initiation for Children: Children ≥ ​30 kg can start at 40 mg q2 wk; those < 30 kg receive 0.8 mg/kg q2 wk.

4. Bio‑analogue Consideration: Within the adalimumab class, switching between Humira and an FDA‑approved biosimilar (e.g., Amjevita) is generally safe; monitor for injection site reactions.

5. Rescue in Dosing Intolerance: If injection site reactions occur, switch to the prefilled syringe or change rotation sites and use over‑the‑counter emollients.

6. Pregnancy Planning: Pre‑conception counseling is essential; discontinue 3 months before conception if possible due to prolonged serum half‑life.

7. Malignancy Signal: Patients with a history of melanoma or lymphoma should be monitored closely; high‐risk patients may require periodic dermatologic evaluation.

8. Rebound Phenomenon: Abrupt cessation can precipitate flare; gradual tapering is preferable if clinical cessation is desired.

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• Key terms summarized: *Humira*, adalimumab, *TNF‑α inhibitor*, *IgG1κ monoclonal antibody*, *subcutaneous* administration, *Crohn’s disease*, *ulcerative colitis*, *rheumatoid arthritis*, *psoriatic arthritis*, *ankylosing spondylitis*, *non‑infectious uveitis*, *TB screening*, *HBV reactivation*, *implantable anti‑injection site reactions*, *biosimilar interchangeability*.