FDA Drug Safety Communication

FDA is removing the warning related to liver injury from the boxed warning of the Letairis (ambrisentan) tablet label. Further evaluation of the clinical trial data and post-marketing safety information has led the FDA to conclude that the risk of liver injury in patients treated with this drug is low.

FDA has also concluded that routine monthly serum liver enzyme testing for patients taking Letairis is not necessary. Healthcare professionals should still continue to order liver enzyme tests when they consider it clinically necessary.

Letairis will continue to be prescribed and dispensed only through the special restricted distribution program called the Letairis Education and Access Program (LEAP).

Healthcare professionals should:

- Be aware that monthly testing of serum liver enzymes is no longer required and drug shipment is no longer contingent upon completion of this testing.

- Be aware that a boxed warning on the risk of serious birth defects and the contraindication for use during pregnancy remains in the label.

- Monthly pregnancy tests will still be required in females of childbearing potential before each shipment of Letairis through the LEAP program.

View the full FDA Drug Safety Communication on FDA.gov