The makers of Definity and Optison, contrasting agents used in ultrasounds of the heart, have agreed to put new black box warnings on the drugs’ package inserts. The Food & Drug Administration (FDA) had asked for the new warnings earlier this month after receiving reports that patients had experienced severe “cardiac reactions” during and following the administration of these agents. According to the FDA, at least 11 deaths have been linked to the use of these contrasting agents.
Definity, made by Bristol Meyers Squibb, and Optison, made by General Electric, are known as micro-bubble contrast agents. They are injected into a patient’s blood stream during an ultrasound of the heart known as an echocardiography. The drugs contain tiny, gas-filled spheres that sharpen the resulting ultrasound picture. This allows doctors to better diagnose heart defects and malfunctions. According to the FDA, micro-bubble contrasting agents are only used in a small number of the echocardiography done each year. Generally, the contrast agents are only used when previous ultrasound pictures are inconclusive.
In announcing the new black box warnings, the FDA said that it knew of at least 200 reports of serious cardiac reactions that involved the use of Definity. The FDA also said that at least 11 deaths had been associated with the administration of these contrasting agents. Four of those fatalities occurred either during infusion or within 30 minutes following the administration of the contrast agent. The FDA said that most of the serious but non-fatal reactions also occurred in the same time frame.
The new black box warning, the FDA’s strictest type, says that Definity and Optison could cause patients to experience cardiac events during, and within 30 minutes of infusion. The new label also warns that Definity and Optison are not suitable in patients who have serious heart problems, including unstable angina, unstable cardiopulmonary disease or a history of acute heart attacks. Finally, the black box recommends that physicians monitor all patients receiving micro-bubble contrast agents for serious cardiopulmonary reactions during the infusion and for 30 minutes following completion of administration. Healthcare providers were also advised to keep resuscitation equipment be on hand for half an hour after injecting the drug.
The new black box warning will apply to Definity immediately. Optison was recalled in 2005 and has been off the market since due to a manufacturing problem. At that time, the FDA had ordered General Electric to stop selling Optison after an inspection of a third-party factory that manufactured the drug turned up problems with its methods for maintaining sterility. General Electric has said that the company plans to reintroduce Optison to the market sometime this year.