FDA reviews cardiac risk of Invirase in combination with Norvir

The FDA has notified healthcare professionals and patients that it is reviewing clinical trial data about a potentially serious effect on the heart associated with the use of Invirase (saquinavir, from Roche) in combination with Norvir (ritonavir, from Abbott). Data suggest that the combination of these two drugs may affect the electrical activity of the heart (ie, prolonged QT or PR intervals). A prolonged QT interval can increase the risk for torsades de pointes. A prolonged PR interval can cause heart block.

The FDA's analysis is ongoing. The agency will provide an update as soon as the review is complete. However, healthcare professionals should be aware of this potential risk for QT or PR interval prolongation. Invirase and Norvir should not be used in patients already taking medications known to cause QT interval prolongation such as Class IA or III antiarrhythmics, or in patients with a history of QT interval prolongation. Patients should not stop taking their prescribed antiviral medications. Patients who are concerned about possible risks associated with using Invirase and Norvir should talk to their healthcare professional.

Invirase and Norvir are indicated for the treatment of HIV infection.

For more information visit www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm201563.htm.