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Quick facts
- Drug class
- Endothelin Receptor Antagonist [EPC], Endothelin Receptor Antagonists [MoA]
- How it is given
- oral
- Type
- human prescription drug
- RxNorm ID
- 722116
We do not publish dosing. How much of this medicine to take, how often, and for how long depends on your age, weight, kidney and liver function, other conditions and other medicines. That is a decision for the person who prescribes or dispenses it. Follow the directions on your own pack and ask your pharmacist if anything is unclear.
What it is used to treat
Ambrisentan tablets are indicated for the treatment of pulmonary arterial hypertension (PAH) (WHO Group 1) in adult patients: To improve exercise ability and delay clinical worsening. Studies establishing effectiveness included predominantly patients with WHO Functional Class II–III symptoms and etiologies of idiopathic or heritable PAH (60%) or PAH associated with connective tissue diseases (34%). Ambrisentan tablet is an endothelin receptor antagonist indicated for the treatment of pulmonary arterial hypertension (PAH) (WHO Group 1) in adult patients: To improve exercise ability and delay clinical worsening. Studies establishing effectiveness included trials predominantly in patients with WHO Functional Class II–III symptoms and etiologies of idiopathic or heritable PAH (60%) or PAH associated with connective tissue diseases (34%) ( 1 ).
About this medicine
Ambrisentan is an endothelin receptor antagonist. The chemical name of ambrisentan is (+)-(2 S )-2-[(4,6-dimethylpyrimidin-2-yl)oxy]-3-methoxy-3,3-diphenylpropanoic acid. It has a molecular formula of C 22 H 22 N 2 O 4 and a molecular weight of 378.42 and has the following structural formula: Figure 1 Ambrisentan Structural Formula Ambrisentan is a white to off-white, crystalline solid. It is a carboxylic acid with a pKa of 4.0. Ambrisentan is practically insoluble in water and in aqueous solutions at low pH. Solubility increases in aqueous solutions at higher pH. In the solid state ambrisentan is very stable, is not hygroscopic, and is not light sensitive. Ambrisentan is available as 5 mg and 10 mg film-coated tablets for once daily oral administration. The tablets include the following inactive ingredients: croscarmellose sodium, lactose monohydrate, magnesium stearate and microcrystalline cellulose. The tablets are film-coated with a coating material containing FD&C Red #40 aluminum lake, lecithin, polyethylene glycol, polyvinyl alcohol, talc, and titanium dioxide. Each square, pale pink ambrisentan tablet contains 5 mg of ambrisentan. Each oval, deep pink ambrisentan tablet contains 10 mg of ambrisentan. Ambrisentan tablets are unscored. structure
How it works
12.1 Mechanism of Action Endothelin-1 (ET-1) is a potent autocrine and paracrine peptide. Two receptor subtypes, ET A and ET B , mediate the effects of ET-1 in the vascular smooth muscle and endothelium. The primary actions of ET A are vasoconstriction and cell proliferation, while the predominant actions of ET B are vasodilation, antiproliferation, and ET-1 clearance. In patients with PAH, plasma ET-1 concentrations are increased as much as 10-fold and correlate with increased mean right atrial pressure and disease severity. ET-1 and ET-1 mRNA concentrations are increased as much as 9-fold in the lung tissue of patients with PAH, primarily in the endothelium of pulmonary arteries. These findings suggest that ET-1 may play a critical role in the pathogenesis and progression of PAH. Ambrisentan is a high-affinity (K i = 0.011 nM) ET A receptor antagonist with a high selectivity for the ET A versus ET B receptor (>4000-fold). The clinical impact of high selectivity for ETA is not known.
Who should not take it
Pregnancy ( 4.1 ) Idiopathic Pulmonary Fibrosis ( 4.2 ) 4.1 Pregnancy Ambrisentan tablets may cause fetal harm when administered to a pregnant female. Ambrisentan tablets are contraindicated in females who are pregnant. Ambrisentan tablets were consistently shown to have teratogenic effects when administered to animals. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to a fetus [see Dosage and Administration ( 2.2 ), Warnings and Precautions ( 5.1 ), and Use in Specific Populations ( 8.1 )] . 4.2 Idiopathic Pulmonary Fibrosis Ambrisentan tablets are contraindicated in patients with Idiopathic Pulmonary Fibrosis (IPF), including IPF patients with pulmonary hypertension (WHO Group 3) [see Clinical Studies ( 14.4 )] .
Warnings and cautions
Fluid retention may require intervention ( 5.2 ). If patients develop acute pulmonary edema during initiation of therapy with ambrisentan tablets, consider underlying pulmonary venoocclusive disease and discontinue treatment if necessary ( 5.3 ). Decreases in sperm count have been observed in patients taking endothelin receptor antagonists ( 5.4 ). Decreases in hemoglobin have been observed within the first few weeks; measure hemoglobin at initiation, at 1 month, and periodically thereafter ( 5.5 ). 5.1 Embryo-fetal Toxicity Based on data from animal reproduction studies, ambrisentan tablets may cause fetal harm when administered during pregnancy and is contraindicated during pregnancy. The available human data for endothelin receptor antagonists do not establish the presence or absence of major birth defects related to the use of ambrisentan tablets. Advise patients who can become pregnant of the potential risk to a fetus. Obtain a pregnancy test prior to initiation of treatment with ambrisentan tablets. Advise patients who can become pregnant to use effective contraception prior to initiation of treatment, during treatment, and for one month after discontinuation of treatment with ambrisentan tablets. When pregnancy is detected, discontinue use as soon as possible [see Dosage and Administration ( 2.2 ), and Use in Specific Populations ( 8.1 , 8.3 )] . 5.2 Fluid Retention Peripheral edema is a known class effect of endothelin receptor antagonists, and is also a clinical consequence of PAH and worsening PAH. In the placebo-controlled studies, there was an increased incidence of peripheral edema in patients treated with doses of 5 or 10 mg ambrisentan tablets compared to placebo [see Adverse Reactions ( 6.1 )] . Most edema was mild to moderate in severity. In addition, there have been postmarketing reports of fluid retention in patients with pulmonary hypertension, occurring within weeks after starting ambrisentan tablets. Patients required intervention with a diuretic, fluid management, or, in some cases, hospitalization for decompensating heart failure. […]
Reported side effects
Clinically significant adverse reactions that appear in other sections of the labeling include: Embryo-fetal Toxicity [see Warnings and Precautions ( 5.1 ), Use in Specific Populations ( 8.1 )] Fluid Retention [see Warnings and Precautions ( 5.2 )] Pulmonary Edema with PVOD [see Warnings and Precautions ( 5.3 )] Decreased Sperm Count [see Warnings and Precautions ( 5.4 )] Hematologic Changes [see Warnings and Precautions ( 5.5 )] Most common adverse reactions (>3% compared to placebo) are peripheral edema, nasal congestion, sinusitis, and flushing ( 6.1 ). To report SUSPECTED ADVERSE REACTIONS, contact Cipla Ltd. at 1-866-604-3268 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Safety data for ambrisentan are presented from two 12-week, placebo-controlled studies (ARIES-1 and ARIES-2) in patients with pulmonary arterial hypertension (PAH). The exposure to ambrisentan in these studies ranged from 6 days to 100 days. In ARIES-1 and ARIES-2, a total of 261 patients received ambrisentan at doses of 2.5, 5, or 10 mg once daily and 132 patients received placebo. The adverse reactions that occurred in >3% more patients receiving ambrisentan than receiving placebo are shown in Table 1. Table 1 Adverse Reactions with Placebo-Adjusted Rates >3% in ARIES-1 and ARIES-2 Placebo (N=132) Ambrisentan (N=261) Adverse Reaction n (%) n (%) Placebo-adjusted (%) Peripheral edema 14 (11) 45 (17) 6 Nasal congestion 2 (2) 15 (6) 4 Sinusitis 0 (0) 8 (3) 3 Flushing 1 (1) 10 (4) 3 Most adverse drug reactions were mild to moderate and only nasal congestion was dose-dependent. Few notable differences in the incidence of adverse reactions were observed for patients by age or sex. […]
Interactions with other medicines
Multiple dose coadministration of ambrisentan and cyclosporine resulted in an approximately 2-fold increase in ambrisentan exposure in healthy volunteers; therefore, limit the dose of ambrisentan to 5 mg once daily when coadministered with cyclosporine [see Clinical Pharmacology ( 12.3 )] . Cyclosporine increases ambrisentan exposure; limit ambrisentan dose to 5 mg once daily ( 7 ).
Use in specific groups
Breastfeeding: Choose ambrisentan tablets or breastfeeding ( 8.2 ). Not recommended in patients with moderate or severe hepatic impairment ( 8.7 ). 8.1 Pregnancy Risk Summary Based on data from animal reproduction studies, ambrisentan tablets may cause fetal harm, including birth defects and fetal death, when administered to a pregnant woman and is contraindicated during pregnancy. There are limited data on ambrisentan tablets use in pregnant women. Available data from postmarketing reports and published literature over decades of use with endothelin receptor antagonists in the same class as ambrisentan tablets have not identified an increased risk of major birth defects; however, these data are limited. Methodological limitations of these postmarketing reports and published literature include lack of a control group; limited information regarding dose, duration, and timing of drug exposure; and missing data. These limitations preclude establishing a reliable estimate of the risk of adverse fetal and neonatal outcomes with maternal endothelin receptor antagonist use. In animal reproduction studies, ambrisentan was teratogenic in rats and rabbits at doses which resulted in exposures of 3.5 and 1.7 times, respectively, the human dose of 10 mg per day [see Animal Data] . If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, advise the patient of the potential hazard to a fetus [see Contraindications ( 4.1 ), Warnings and Precautions ( 5.1 )] . The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2-4% and 15-20%, respectively. Data Animal Data Ambrisentan was teratogenic at oral dosages of ≥15 mg/kg/day (AUC 51.7 h•μg/mL) in rats and ≥7 mg/kg/day (24.7 h•μg/mL) in rabbits; it was not studied at lower dosages. These dosages are of 3.5 and 1.7 times, respectively, the human dose of 10 mg per day (14.8 h•μg/mL) based on AUC. […]
If too much is taken
There is no experience with overdosage of ambrisentan tablets. The highest single dose of ambrisentan tablets administered to healthy volunteers was 100 mg, and the highest daily dose administered to patients with PAH was 10 mg once daily. In healthy volunteers, single doses of 50 mg and 100 mg (5 to 10 times the maximum recommended dose) were associated with headache, flushing, dizziness, nausea, and nasal congestion. Massive overdosage could potentially result in hypotension that may require intervention.
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This page is built from the openFDA record of the U.S. Food and Drug Administration's approved labelling for this product, effective 22 April 2025. Label text has been shortened and reformatted for readability; safety wording has not been altered in meaning. FDA labelling describes products approved in the United States — brand names, strengths, formulations and approved uses may differ in your country. Always read the leaflet that comes with your own pack. PocketsInfo is not affiliated with, and is not endorsed by, the FDA. Retrieved 2026-07-30.