Liver Function Testing for Patients Taking Letairism (Ambrisentan)
Issued by the Scientific Leadership Council
This information is for general information only. These guidelines may not apply to your individual situation. You should rely on the information and instructions given specifically to you by your PH specialist and/or the nurses at your PH Center. This information is general in nature and may not apply to your specific situation. It is not intended as legal, medical or other professional advice, and should not be relied upon as a substitute for consultations with qualified professionals who are familiar with your individual needs.
The U.S. Food and Drug Administration (FDA) recently removed the black box warning related to liver injury for Letairis (ambrisentan) because of a low observed incidence of liver toxicity. Although LFT monitoring is no longer mandatory, physicians in the Scientific Leadership Council of the Pulmonary Hypertension Association believe it is prudent to test liver function at the outset of all treatments for pulmonary hypertension and, at the prescriber's discretion, at periodic intervals thereafter.
The package insert for Letairis includes the following:
* Letairis is not recommended in patients with moderate or severe hepatic impairment.
* Letairis should be discontinued if hepatic transaminases rise to > 5XULN or if elevations in hepatic transaminases are accompanied by bilirubin> 2XULN.
* Continued monitoring LFTs when it is considered clinically necessary.
* As with any drug, side effects should be reported to the FDA MedWatch Program.
The Letairis (ambrisentan) fact sheet on our website will be updated soon.