infliximab

Infliximab is an antibody administered intravenously that is used for treating several chronic inflammatory diseases. Infliximab works by blocking the effects of tumor necrosis factor alpha (TNF alpha), a substance made by cells of the body which has an important role in promoting inflammation. There are two other injectable drugs that block TNF alpha—adalimumab (Humira) and etanercept (Enbrel). Specifically, infliximab is used for treating the inflammation of

• Crohn's disease,
• rheumatoid arthritis,
• psoriasis,
• ankylosing spondylitis, and
• psoriatic arthritis.

By blocking the action of TNF-alpha, infliximab reduces the signs and symptoms of inflammation. Infliximab does not cure Crohn's disease, psoriatic arthritis, or rheumatoid arthritis. Infliximab can retard the destruction of joints by rheumatoid arthritis. The FDA approved infliximab in August 1998.

Infliximab is approved for use alone or combined with methotrexate (Rheumatrex, Trexall) for treating moderate to severe rheumatoid arthritis.

Infliximab is used for reducing the signs and symptoms of inflammation in moderate to severe Crohn's disease and Crohn's disease in which there are fistulas (passageways created when the inflammation penetrates beyond the wall of the intestine).

It also is approved for the treatment of active psoriatic arthritis. Infliximab is helpful in reducing the joint inflammation of juvenile rheumatoid arthritis, ankylosing spondylitis, plaque psoriasis, and psoriatic arthritis.

It also has been found to be helpful in treating the inflammation of uveitis and sarcoidosis that is not responding to traditional therapies.

Infliximab is approved for use in pediatric patients with moderately to severely active Crohn's disease who have had an inadequate response to conventional therapy.

WARNING

Infliximab should be discontinued if serious reactions occur. Serious infections have been reported with other drugs that block TNF- alpha, and infections have been reported during treatment with infliximab. Therefore, infliximab should not be used in patients with serious infections. Moreover, infliximab should be discontinued if a serious infection develops during treatment. Testing for tuberculosis (PPD tests for TB) should be doneprior to treatment with infliximab because of reports of reactivation of tuberculosis in patients taking infliximab. Such patients should be treated for tuberculosis.

Decreased white and red blood cell and decreased platelet counts have been reported with infliximab. Vasculitis (inflammation of the arteries) also has been reported.

Patients with Crohn's disease or rheumatoid arthritis, particularly patients with highly active disease and/or chronic exposure to immunosuppressant therapies, may be at a higher risk (up to several fold) than the general population for the development of malignant lymphoma. More malignancies have been observed in open-label, uncontrolled clinical studies at a rate several-fold higher than expected in the general population. In controlled studies of TNF-alpha blocking agents, including infliximab, more cases of lymphoma and other malignancies have been observed among patients receiving the agents than among control group patients.

Common side effects

The most common side effects of infliximab include:

• upper respiratory tract infections,
• urinary tract infections,
• cough,
• rash,
• back pain,
• nausea,
• vomiting,
• abdominal pain,
• headache,
• weakness and
• fever.

Other important side effects include:

• low or high blood pressure,
• chest pain,
• difficulty breathing,
• rash,
• itching,
• fever and
• chills

Reactions listed above could indicate an allergy to the infliximab. They are more common among patients who develop antibodies to infliximab and are less likely to occur in patients who are taking drugs that suppress the immune system, such as methotrexate.

Infliximab is administered intravenously. The recommended dose is a 5 mg/kg infusion at 0, 2, and 6 weeks and then 5 mg/kg every 8 weeks for moderate to severe active Crohn's disease or fistulizing Crohn's disease in adult or pediatric patients. Adults who initially responded then lost response may be treated with 10 mg/kg.

The recommended dose for the treatment of moderately to severely active rheumatoid arthritis is 3 mg/kg at 0, 2, and 6 weeks followed by 3 mg/kg every 8 weeks. Infliximab should be combined with methotrexate. If response is incomplete, up to 10 mg/kg or treating every 4 weeks may be tried.

Ulcerative colitis, psoriatic arthritis, and plaque psoriasis are treated with a 5 mg/kg infusion at 0, 2, and 6 weeks and then 5 mg/kg every 8 weeks.

Ankylosing spondylitis is treated with a 5 mg/kg infusion at 0, 2, and 6 weeks then 5 mg/kg every 6 weeks.

Because infliximab may reduce the response of the immune system, it should not be administered with vaccines containing live bacteria or viruses. Combining infliximab with anakinra (Kineret), abatacept (Orencia) or tocilizumab (Actemra), drugs that also reduce the response of the immune system, may increase the risk of serious infections.

Use of infliximab in pregnant women has not been adequately evaluated.

It is not known if infliximab is secreted in breast milk, and, therefore, if there are effects on the nursing infant.

What preparations of infliximab are available?

Powder for intravenous injection, 100 mg

How should I keep infliximab stored?

Infliximab should be refrigerated at 2 C - 8 C (36 F - 46 F)