Infliximab (Remicade) And Etanercept (Enbrel): Serious Infections And Tuberculosis

Main Category: Tuberculosis
Article Date: 11 Oct 2004 - 0:00 PDT


Tumour necrosis factor-alpha (TNF-α) is a proinflammatory cytokine synthesized in response to infectious or inflammatory stimuli. TNF-α antagonists have been shown to be effective in the treatment of signs and symptoms of rheumatoid arthritis and other autoimmune diseases. Infliximab (Remicade) is indicated in adults for rheumatoid arthritis (in combination with methotrexate), Crohn's disease and fistulizing Crohn's disease. Etanercept (Enbrel) is indicated for rheumatoid arthritis in adults and polyarticular juvenile rheumatoid arthritis in patients aged 4 to 17 years.

Serious infections, particularly tuberculosis (TB), are recognized risks for patients receiving TNF-α antagonists, and warnings to that effect are prominent in the product monographs.2,3 Many serious infections have occurred in patients taking immunosupressive therapy concomitantly, which, in addition to the underlying disease, could predispose them to infections.

Health Canada received a total of 697 reports of suspected adverse reactions (ARs) to infliximab and 536 to etanercept from Jan. 1, 2000, to May 31, 2004 (See Table). Reports of infection were considered serious when the infection was life threatening or resulted in death, disability, hospital admission or prolonged hospital stay (as defined in the Food and Drug Regulations). The types of serious infections are listed in See Table. Reports of TB comprised those of new cases (infliximab 3, etanercept 0), reactivation of latent TB (infliximab 3, etanercept 0) and cases in which the patient was prescribed antituberculous medication (infliximab 4, etanercept 2). There were 4 reports of pulmonary or pleural TB (infliximab 4, etanercept 0), 4 reports of extrapulmonary TB (infliximab 4, etanercept 0) and 4 reports in which the type of TB was not specified (infliximab 2, etanercept 2).

A number of registries have been established to assist in assessing the long-term safety and efficacy of TNF-α antagonists. In France the program is particularly interested in infections and lymphomas. In Alberta a systematic approach has been developed to collect data on effectiveness and ARs for all Alberta patients receiving these agents for the treatment of rheumatoid arthritis.

Health care professionals are reminded of the following important safety information included in the Enbrel and Remicade product monographs:

-- Caution should be exercised when considering the use of TNF-α antagonists in patients with chronic infection, a history of recurrent or latent infection, including TB, or an underlying condition that may predispose them to infection.

-- TNF-α therapy should not be initiated in patients with a clinically important, active infection.

-- New infections should be closely monitored and therapy discontinued if the infection becomes serious.

Patients should be instructed in how to recognize early signs and symptoms of infection and be advised to seek medical attention when they occur.

CLICK HERE TO SEE TABLES - Canadian Adverse Reaction Newsletter Volume 14, Issue 4, October 2004

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