Letairis is a medication used to treat pulmonary arterial hypertension (PAH). This prescription drug comes as a tablet that is taken once daily. Dosing guidelines will vary, based on how you tolerate the drug, other medications you are taking, and various other factors. Side effects are possible and include swelling, inflamed sinuses, and nasal congestion.
Letairis® (ambrisentan) is a prescription medication approved to treat people with pulmonary arterial hypertension (PAH), which is high blood pressure in the blood vessels of the lungs. Letairis can help improve exercise ability and can slow down the worsening of the condition.
Letairis is made by Gilead Sciences, Inc.
Letairis is an endothelin receptor antagonist. Endothelins are proteins that have a variety of actions in the body, including effects on the heart, blood vessels, lungs, and kidneys. One of the things endothelins do is to cause blood vessels to constrict (narrow). People with PAH have higher-than-normal levels of endothelins in the body.
Endothelin can bind to two receptors. Letairis works by blocking one of those receptors (endothelin A, or ETA receptor), preventing endothelin from binding to the receptor. This helps block the actions of the extra endothelin in people with PAH.
Clinical studies have shown that Letairis can improve exercise ability in people with PAH. In one study, people who took Letairis were able to walk 44 meters farther in 6 minutes, on average, after 12 weeks of treatment. In comparison, those who took a placebo (a "sugar pill" with no active ingredient) walked 8 meters less in 6 minutes after 12 weeks.
Letairis was also shown to slow clinical worsening of PAH in clinical trials. In these studies, people given Letairis had less worsening of their condition over 12 weeks, which meant they were less likely to:
- Need to go the hospital for their PAH symptoms
- Need additional PAH treatment
- Stop Letairis because their PAH got worse
- Have a lung transplant or other surgeries for PAH