A multiple sclerosis drug is under investigation by the FDA after a patient dies quickly after taking it.

FOX's Colleen Cappon reports in today's "Housecall for Health":

U.S. health regulators are investigating the multiple sclerosis drug Gilenya after a patient died within 24 hours of taking a first dose.  The 59-year-old man had been living with MS for 10 years.

The Food & Drug Administration said it cannot yet confirm if it was the drug that caused his death, but said healthcare professionals should monitor patients for signs of a slow heart rate within six hours of the first dose of Gilenya.

Housecall for Health, I'm Colleen Cappon, FOX News Radio.