InfliximabRx

Trade Names: Remicade

Drug Class: Biologic DMARD, TNF antagonist

Preparations: 100-mg injection

Dose:  RA: 3 mg/kg by slow intravenous infusion (at least 2 hours) at 0, 2, and 6 weeks and then repeated every 8 weeks. The maintenance dose required ranges from 3 to 10 mg/kg every 4–8 weeks. Dose escalations over time (5–10 mg/kg or at 4- to 6-week intervals) may be necessary to control disease in a minority of patients with aggressive disease.
Crohn’s disease, ulcerative colits, psoriatic arthritis, ankylosing spondylitis: 5 mg/kg by slow intravenous infusion at 0, 2, and 6 weeks and then repeated every 8 weeks.

Indications: RA, psoriatic arthritis, psoriasis, ankylosing spondylitis, Crohn’s disease, ulcerative colitis

Mechanism of Action: A chimeric monoclonal antibody that binds to  TNF and blocks its ability to bind with its receptor on the cell.

Contraindications: Hypersensitivity, untreated tuberculosis and other opportunistic infections, sepsis, active infection, chronic localized or recurrent infections, demyelinating disease, optic neuritis, moderate-to-severe heart failure.

Precautions: Increased risk of serious infections including TB and fungal. Exclude latent or active  TB with a skin test or TB blood test (interferon-gamma release assays or IGRA). Caution in debilitated or high risk of infection.  Exclude active hepatitis B infection or carriage.  Avoid live virus vaccines and BCG. Do not use with other biologics. May exacerbate pre-exisiting demyelinating disease and heart  failure.

Monitoring: Monitor during infusion. Monitor clinically for infection. Periodic CBC. After therapy started, additional TB testing may be indicated for individuals likely to have exposure to TB.

Pregnancy Risk: B

Adverse Effects
Common: Infusion reactions (rash, hives, itching, tachycardia, fever, nausea) are usually mild to moderate and can often be controlled with acetaminophen and antihistamines and slowing the rate of infusion. Positive antinuclear antibody, positive antinuclear and double stranded DNA antibody, anti-infliximab antibodies.
Less common: Serious infusion reactions occur in <2% of patients and may manifest as severe rashes, hypotension, hemodynamic instability, chest tightness, severe dyspnea, or a feeling of impending doom. Cessation and aggressive treatment may require intravenous corticosteroids and hemodynamic support. Allergy, infection (bacterial, but particularly opportunistic infections such as tuberculosis, listeriosis, and histoplasmosis).
Rare: Anaphylaxis, lymphoma (including fatal hepatosplenic T-cell lymphoma), hepatitis, demyelinating CNS disorders, optic neuritis, seizures, pancytopenia, drug-induced lupus, reactivation of hepatitis B, new onset psoriasis.

Drug Interactions: Concurrent use of high-dose steroids and other immunosuppressants may increase risk of infection.

Patient Instructions: Avoid live virus vaccines; avoid pregnancy; stop injections and call your doctor if an infection or fever develops that lasts more than a few days.

Comments: TNF antagonists are among the most effective treatments for RA. Patients start to respond quickly, usually within 4–6 weeks but maximum response may take 4-6 months.  Combined therapy with MTX is more effective than either drug alone. TNF antagonists are being explored in a range of diseases such as sarcoidosis and inflammatory eye disease. Risk of tuberculosis may be lower with etanercept than other TNF antagonists; comparative risk of adverse effects among individual TNF antagonists is not clear and side effects likely a class effect. Patients may form antibodies to anti-TNF drugs that decrease their effect. Concurrent treatment with MTX may reduce the frequency of this.

Clinical Pharmacology: Half-life is 7-12 days. Biologic agents are not metabolized and thus have few drug interactions.

Cost: $$$$$

BIBLIOGRAPHY

Bombardier C, Hazlewood GS, Akhavan P, et al. Canadian Rheumatology Association recommendations for the pharmacological management of rheumatoid arthritis with traditional and biologic disease-modifying antirheumatic drugs: part II safety. J Rheumatol 2012;39:1583-602. PMID: 22707613.

Singh JA, Furst DE, Bharat A. et al.2012 Update of the 2008 American College of Rheumatology recommendationsfor the use of disease-modifying antirheumatic drugs and biologic agents in the treatment of rheumatoid arthritis.Arthritis Care Res 2012;64(5):625-39.PMID:22473917