The Food and Drug Administration has just issued a surprising new warning about two drugs doctors commonly use to diagnose cardiovascular disease: they may themselves cause heart attacks. The two drugs, called Lexiscan and Adenoscan, are injected before stress tests to diagnose coronary artery disease.
The American Heart Association describes a stress test as one intended to gauge heart health under the increased workload caused by exercise. As its workload increases, the heart has to pump more blood to fuel the body, so a stress test can reveal whether a cardiovascular problem, such as a blocked artery, has reduced the blood flow to the heart, causing damage.
Lexiscan and Adenoscan dilate the heart’s arteries and increase blood flow in the body. During stress test, one of them is intentionally injected to accomplish that, making the simultaneous medical images of the heart easier to read. This allows the doctor to spot any areas in the heart that may be damaged.
Unfortunately, the drugs may have a rare, but potentially dangerous or even fatal, secondary effect. After an Adenoscan or Lexiscan injection, the increased blood flow may cause serious problems if the patient already has a partially-obstructed artery.
As water seeks the path of least resistance, increased blood flow in these patients may primarily head into the healthy arteries, instead of the partially obstructed ones. A corresponding drop in the blood flow to the unhealthy arteries could cause a sudden heart attack.
Earlier this year, the FDA began receiving reports of heart attacks and deaths that potentially associated with Lexiscan and Adenoscan and put them on a list of drugs to monitor. By Nov. 20, the agency had received reports of 32 heart attacks and 56 deaths occurring after one of the drugs had been administered, so it issued this alert.
The FDA warns doctors not to use these potentially dangerous or fatal medications in patients with known symptoms of cardiovascular instability — and to have resuscitation equipment on hand whenever stress tests using either drug are performed.
You have the right to know the potential side effects of any medication you are prescribed, and you should ask if you’re not offered that information. If you are concerned you may have heart or cardiovascular disease, discuss the rare but real risk of heart attack or wrongful death from using Adenoscan or Lexiscan during a stress test.
- TIME, “Chemicals in Heart Stress Tests Can Trigger Heart Attacks,” Alexandra Sifferlin, Nov. 20, 2013
- U.S. Food and Drug Administration press release, “FDA warns of rare but serious risk of heart attack and death with cardiac nuclear stress test drugs Lexiscan (regadenoson) and Adenoscan (adenosine),” Nov. 20, 2013