FDA Announces Safety Concern for HIV Drug Combo
The U.S. Food and Drug Administration (FDA) released preliminary data Feb. 25 suggesting that Invirase (saquinavir) in combination with Norvir (ritonavir) may have potentially important adverse effects on the heart.
When used together, the FDA states in a Feb. 23 news release, the drugs may cause prolongation of the QT and PR intervals on an electrocardiogram (EKG). Prolongation of the QT interval may lead to a condition known as torsades de pointes, an abnormal heart rhythm. Prolongation of the PR interval also may lead to an abnormal heart rhythm known as heart block. With torsades de pointes or with heart block, patients may experience lightheadedness, fainting, or abnormal heart beats. In some cases, torsades de pointes may progress to a life-threatening irregular heartbeat known as ventricular fibrillation.
Although review of the data is ongoing, preliminary findings suggest that some patients using Invirase and Norvir may be at an increased risk for heart abnormalities leading to irregular heart rhythms. For example, the risk for torsades de pointes may be increased in patients who also use medications known to cause a heart disturbance called QT interval prolongation. The risk may be increased in patients with a history of QT interval prolongation, as well.
Physicians should discuss with patients using Invirase any questions or concerns they have about the drug. Patients and health care professionals should report any side effects from Invirase use to the FDA’s MedWatch program.
Invirase is an antiretroviral medication that was first approved in 1995. It is used in combination with Norvir and other antiretroviral medicines to treat human immunodeficiency virus (HIV) in adults.
Invirase is marketed by San Francisco-based Genentech, a subsidiary of the Roche Group. Norvir is marketed by Abbott Park, Ill.-based Abbott Laboratories.