FDA is updating healthcare professionals about recent changes made to the Boxed Warning, Warnings, and Contraindications sections of the prescribing information for micro-bubble contrast agents, a sterile suspension of perflutren gas microspheres, indicated for use in certain patients with suboptimal echocardiograms, to opacify the left ventricular chamber and to improve the delineation of the left ventricular endocardial border.

These changes reflect conclusions of FDA reviews of information received following the addition of new contraindications and warnings in October 2007. The revised Boxed Warning and Warnings highlight the risk of serious cardiopulmonary reactions during or within 30 minutes following the administration of these products and recommend that high risk patients with pulmonary hypertension or unstable cardiopulmonary conditions be closely monitored during and for at least 30 minutes post administration of these contrast agents. In addition, several of the Contraindications that were added to the labeling in October, 2007 were removed because FDA determined that, in some patients, the benefits from the diagnostic information obtained through the use of Definity or Optison may outweigh the risk for serious cardiopulmonary reactions, even among some patients at particularly high risk for these reactions.

Read the complete MedWatch 2008 safety summary, including links to the Information for Healthcare Professionals and previous MedWatch alerts, at: http://www.fda.gov/medwatch/safety/2008/safety08.htm#Microbubble