The heart drug Amiodarone, sold under the trade name Cordarone, seems to have serious side effects in women but not men. Atrial fibrillation is a heartbeat disturbance in which the walls of the upper chambers of the heart vibrate rapidly. This "arrhythmia" raises the risk that clots may form in the heart and possibly travel to the brain, causing a stroke. For this reason, patients are often treated with blood thinners to prevent these clots from forming. Amiodarone is more effective than other drugs for maintaining a normal heartbeat in patients with atrial fibrillation, but this comes at the cost of more side effects. Researchers from the Beth Israel Deaconess Medical Center, Boston evaluated the outcomes of 973 patients who were newly diagnosed with atrial fibrillation. The average age was 66 years, and 40 per cent were female. During an average follow-up of two years, 46 men and 39 women underwent the placement of a permanent pacemaker because of a slow heartbeat. Amiodarone use was identified as a risk factor for requiring a pacemaker. However, further analysis showed that this only applied to women, and not the men. Women who used Amiodarone were nearly five times more likely to require a pacemaker than those who did not. Thus, additional caution should be taken when Amiodarone is being prescribed to women, particularly elderly women.
Archives of Internal Medicine,
August 2007