According to a recent press release from the U.S. Food and Drug Administration (FDA), using Invirase (saquinavir) and Norvir (ritonavir) in combination may lead to heart problems in some HIV and AIDS patients.

Invirase is an antiretroviral drug from the class known as protease inhibitors. It is used to treat HIV infection, and is used in combination with Norvir to enhance its effects.

Recently acquired data suggests that using these two drugs together can cause a condition known as torsades de pointes, otherwise known as abnormal heart rhythm. This can also lead to a type of abnormal heart rhythm known as heart block. Symptoms of torsades de pointes include lightheadedness, abnormal heart beats, and fainting. Torsades de pointes may even lead to ventricular fibrillation, a potentially life-threatening and severely abnormal heart rhythm.

Preliminary reviews of the data suggest that patients who use medications that can cause heart disturbances may be at risk for torsades de pointes if they also use Invirase and Norvir.

So far, the FDA has recommended that patients using Invirase talk to their doctors before making any changes to their treatment regimens. Also, patients should report any unusual side effects to the FDA’s MedWatch program.

For more information please see the FDA Web site.