FDA is alerting healthcare professionals about serious cardiopulmonary reactions from the ultrasound micro-bubble contrast agents Definity or Optison. These products are used during echocardiography to enhance a cardiac image.

Eleven deaths and about 200 serious reactions have been reported. Four of the 11 deaths were caused by cardiac arrest, either during administration of the contrast agent or within 30 minutes afterwards. Most of the serious but non-fatal reactions also occurred in this time frame. Many of these reports describe symptoms suggestive of anaphylactoid reactions, including dyspnea or urticaria. Other reports describe cardiopulmonary reactions such as cardiac or respiratory arrest, loss of consciousness, convulsions, symptomatic arrhythmias, cardiac ischemia, hypotension, respiratory distress and oxygen desaturation, without signs or symptoms of an allergic reaction.

Because of this, the labeling for Definity and Optison will now warn about the risks of both cardiopulmonary and hypersensitivity reactions. The labeling will recommend monitoring vital signs, cardiac rhythm and oxygen saturation, and having equipment for resuscitation and trained personnel readily available.

In addition, these products will now be contraindicated in patients with unstable cardiopulmonary status, such as those with unstable angina, acute myocardial infarction, respiratory failure, or congestive heart failure that's recently worsened.