1. Clinical Overview
Adalimumab is a recombinant human IgG1 monoclonal antibody that specifically binds to human tumor necrosis factor-alpha (TNF-α), neutralizing its biological activity. It is a high-cost, high-efficacy biologic disease-modifying anti-rheumatic drug (bDMARD) used for a range of autoimmune and inflammatory conditions. In India, it is a critical therapy for patients with moderate to severe disease activity who have failed conventional synthetic DMARDs.
| Onset | Duration | Bioavailability |
|---|---|---|
| Clinical improvement is typically observed within 2-12 weeks of initiating therapy, with peak effect often seen after 12-24 weeks of continuous treatment. | The pharmacodynamic effect persists for approximately 2 weeks, corresponding to its dosing interval, but the clinical therapeutic effect is maintained with continued dosing. | Approximately 64% following a single 40 mg subcutaneous injection. |
2. Mechanism of Action
Adalimumab is a fully human monoclonal antibody that binds with high affinity and specificity to soluble and transmembrane forms of human TNF-α, a pro-inflammatory cytokine. By binding to TNF-α, it prevents its interaction with the p55 and p75 cell surface TNF receptors (TNFR1 and TNFR2), thereby neutralizing TNF-α's biological activity. This includes inhibition of TNF-mediated induction of other pro-inflammatory cytokines (IL-1, IL-6), adhesion molecules, and matrix metalloproteinases.
3. Indications & Uses
- Moderate to Severe Rheumatoid Arthritis (in combination with Methotrexate)
- Active Psoriatic Arthritis
- Active Ankylosing Spondylitis
- Moderate to Severe Crohn's Disease (adults and pediatric ≥6 years)
- Moderate to Severe Ulcerative Colitis
- Moderate to Severe Chronic Plaque Psoriasis (adults)
4. Dosage & Administration
Adult Dosage: Rheumatoid Arthritis, Psoriatic Arthritis, Ankylosing Spondylitis: 40 mg subcutaneously every other week. Dose can be increased to 40 mg weekly in RA patients not on methotrexate. Plaque Psoriasis: Initial dose 80 mg, then 40 mg every other week starting one week after initial dose. Crohn's Disease/Ulcerative Colitis: Initial dose 160 mg (four 40 mg injections on Day 1 or split over two days), second dose 80 mg two weeks later, maintenance dose 40 mg every other week.
Administration: For subcutaneous use only. Administer in the thigh or abdomen (avoid 2-inch area around navel). Rotate injection sites. Allow prefilled syringe/pen to reach room temperature (15-30 minutes) before injection. Do not shake. Inspect for particulate matter or discoloration. Use aseptic technique. Patient can be trained for self-administration.
5. Side Effects
Common side effects may include:
- Injection site reactions (erythema, itching, pain, swelling)
- Upper respiratory tract infections (sinusitis, pharyngitis)
- Headache
- Rash
- Nausea
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Abatacept | Increased risk of serious infections; concomitant use not recommended. | Major |
| Anakinra | Increased risk of serious infections and neutropenia; concomitant use not recommended. | Major |
| Live Vaccines (MMR, Varicella, Yellow Fever, Oral Polio, Rotavirus) | Risk of disseminated infection; contraindicated. | Major |
| Methotrexate | Reduces clearance of adalimumab, potentially increasing its concentration. Standard combination therapy in RA. | Moderate |
| Other TNF blockers | Increased risk of infections; not recommended. | Major |
| Warfarin | Case reports of increased INR; monitor INR closely. | Moderate |
7. Patient Counselling
- DO store in refrigerator (2°C to 8°C). Do not freeze.
- DO keep in original carton to protect from light.
- DO allow the prefilled pen/syringe to reach room temperature before injecting.
- DO rotate injection sites.
- DO report any signs of infection (fever, cough, flu-like symptoms, sores) immediately.
- DO complete all recommended screenings (TB, Hepatitis B) before starting.
- DONT use if the solution is cloudy, discolored, or has particles.
- DONT inject into tender, bruised, red, or hard skin.
- DONT stop other medications (like methotrexate) unless advised by your doctor.
- DONT receive live vaccines while on this therapy.
8. Toxicology & Storage
Overdose: Single doses up to 10 mg/kg have been administered without toxic effects. In case of overdose, monitor closely for signs of infection or other adverse effects. No specific antidote.
Storage: Store in a refrigerator at 2°C to 8°C. Do not freeze. Keep the prefilled syringe or pen in the original carton to protect from light. If needed, a single prefilled device can be stored at room temperature (up to 25°C) for a maximum of 14 days, protected from light. Do not store above 25°C. Do not shake. Keep out of reach of children.