In "TNF Inhibitors: A New Age in Rheumatoid Arthritis Treatment" (February) Diana L. Anderson failed to mention a serious complication for which nurses can provide potentially life - saving patient education. Approximately one-third of the world's population and 9 million to 14 million people in the United States are infected with latent tuberculosis. 1 Many are unaware that they are infected. Asking patients about risk factors for tuberculosis before starting a tumor necrosis factor (TNF) inhibitor could save a life and prevent spread of the disease.
Immunosuppression resulting from TNF inhibitors has led to reactivation of latent tuberculosis in many patients. Authors of one study found 70 reported cases of tuberculosis after infliximab (Remicade) therapy reported to the U.S. Food and Drug Administration's MedWatch system as of May 29, 2001. 2 Of these patients, 48 developed active tuberculosis after three infusions or fewer, and 64 were from countries with a low incidence of tuberculosis. The rate of tuberculosis infection was much higher than those of other opportunistic infections associated with this drug.
Stephen Paget of Columbia University recommends the following 3:
* Perform a purified protein derivative (PPD) of tuberculin skin test in all patients before starting infliximab and etanercept (Enbrel). In patients who have already started therapy, a PPD skin test should be done, but a negative result could be due to immunosuppression and not infection. Chest X-ray and clinical follow-up should be performed.
* In patients with a negative PPD test, a TNF inhibitor can be started and the patient monitored for active tuberculosis.
* A chest X-ray should be performed in patients with a positive PPD result. If the X-ray is normal, nine months of isoniazid (Laniazid, Nydrazid) 300 mg and vitamin B6 50 mg should be given daily. Concomitant use of TNF inhibitors is appropriate.
* If the chest X-ray shows signs typically seen in inactive tuberculosis and the PPD result is positive, at least three months of isoniazid and vitamin B6 is indicated before treatment with infliximab or etanercept is started. Or if active tuberculosis is a possibility, consultation with a pulmonary or infectious disease specialist is appropriate.
* If the PPD result is positive but the patient has already had a course of isoniazid, TNF inhibitors can be started along with clinical observation for tuberculosis.
Carolyn Bargman, MA, RN
Denver, CO
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