The Food and Drug Administration (FDA) has revised the label of fingolimod (Gilenya), a drug used to prevent exacerbations of relapsing forms of multiple sclerosis (MS) and delay the progression of physical symptoms of MS. The labeling changes, which are related to the potential for serious and potentially life-threatening bradycardia, were made after the FDA completed an evaluation of a reported patient death after the first dose of fingolimod. The FDA also reviewed clinical trial and postmarketing data that weren't available at the time the product was approved.

Fingolimod has always been known to pose a risk of significant bradycardia after the first dose. Previously, the recommendation was to monitor the patient for six hours after the first dose. The FDA has now determined that the bradycardic effect is biphasic, the first phase being six hours after the first dose and the second phase between 12 and 20 hours after the initial dose.

The current recommendation is hourly heart rate and blood pressure monitoring after drug administration for at least six hours after the first dose, with electrocardiograms at baseline before dosing and at the end of the monitoring period. If the patient develops a pulse of less than 45 beats per minute or a new second-degree or higher atrioventricular block, she or he needs to be monitored until it resolves. If the patient's lowest pulse rate occurs at the end of the six-hour monitoring period, the rate must be monitored until it has increased. Patients developing symptomatic bradycardia require continuous cardiac monitoring; pharmacologic treatment and overnight assessment may be necessary. Other patients who should be observed overnight include those at high risk for symptomatic bradycardia or heart block, those with a prolonged corrected QT interval at baseline or during the observation period, and those taking drugs that can produce torsades de points (a lethal form of ventricular tachycardia).

Fingolimod is contraindicated if the patient has a history within the last six months of myocardial infarction, unstable angina, stroke, transient ischemic attack, or hospitalization for an acute exacerbation of heart failure; has a history of or currently has a Mobitz type II second-degree atrioventricular block, a third-degree atrioventricular block, or sick sinus syndrome (unless the patient has a pacemaker); or is receiving treatment with a class Ia antiarrhythmic drug (such as quinidine) or a class III antiarrhythmic drug (such as amiodarone).

Nurses who administer fingolimod to patients with MS should be aware of these labeling changes and read the label carefully for full information about appropriate monitoring of the patient. To read the FDA Drug Safety Communication regarding fingolimod, go to http://1.usa.gov/KltbpT.