Warnings about drugs used with ultrasounds

The Food and Drug Administration (FDA) is reportedly about to issue "blackbox" warnings for drugs used to enhance the images of ultrasound machines in the diagnosing of heart problems.

A black box warning is the strongest type of warning for medical products.

These particular drugs are injected into some patients' veins before doctors view the heart by using an ultrasound procedure called echocardiography.

FDA will issue information to doctors regarding the serious risks associated with the drugs.

The drugs Definity and Optison are made from microscopic gas-filled spheres enclosed in tiny capsules of protein or fatty material and are injected into the veins of patients before their hearts are examined with ultrasound.

They enable doctors to visualize the borders of the heart more clearly and identify abnormalities.

The warning follows an FDA investigation into reports of deaths and serious cardiopulmonary reactions after people were injected with either of the products; it will advise doctors not to prescribe the drugs to patients with unstable angina, acute heart attacks and unstable cardiopulmonary disease.

The FDA says millions of people have echocardiograms each year, but only a small group of them receive Definity or Optison.

Definity is manufactured by Bristol-Myers Squibb and Optison is made by GE Healthcare; it was recalled in November 2005 because of manufacturing problems and it was about to be relaunched this year in September or October.

GE Healthcare says more than 1 million doses of Optison have been given and very few adverse reactions have been reported.