Two medicines, side by side
Ambrisentan vs macitentan
Ambrisentan and macitentan are both labeled for pulmonary arterial hypertension. Drugs@FDA records approvals of ambrisentan since 2007 and of macitentan since 2013. How each works, in its label's words: Ambrisentan, “Two receptor subtypes, ET A and ET B , mediate the effects of ET-1 in the vascular smooth muscle and endothelium.”; Macitentan, “Endothelin (ET)-1 and its receptors (ET A and ET B ) mediate a variety of deleterious effects, such as vasoconstriction, fibrosis, proliferation, hypertrophy, and inflammation.”
Check it at the source: the ambrisentan FDA label on DailyMed (effective September 3, 2026); the macitentan FDA label on DailyMed (effective April 11, 2025).
Highlights of the ambrisentan record
Ambrisentan (Letairis) · label of September 3, 2026
EMBRYO-FETAL TOXICITY Ambrisentan tablets are contraindicat ed for use during pregnancy because it may cause major birth defects if used by pregnant patients, based on studies in animals [see Contraindications (4.1), Warnings and Precautions (5.1), and Use in Specific Populations (8.1)]. Therefore, for females of reproductive potential, exclude pregnancy before the initiation of treatment must use acceptable methods of contraception during treatment with ambrisentan tablets.
Used for
From the label: indicationsAmbrisentan 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%). […]
On the market
- Earliest approval on file
- June 15, 2007
- Generic labelers
- 12 labelers
- Pharmacy cost
- $8.02 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 0
Highlights of the macitentan record
Macitentan (Opsumit) · label of April 11, 2025
EMBRYO-FETAL TOXICITY OPSUMIT is contraindicated for use during pregnancy because it may cause fetal harm based on animal data [see Contraindications (4.1), Warnings and Precautions (5.1), Use in Specific Populations (8.1) ]. Therefore, for females of reproductive potential, exclude pregnancy before the start of treatment with OPSUMIT.
Used for
From the label: indicationsOPSUMIT is an endothelin receptor antagonist (ERA) indicated for the treatment of pulmonary arterial hypertension (PAH, WHO Group I) in adults to reduce the risks of disease progression and hospitalization for PAH ( 1.1 ). 1.1 Pulmonary Arterial Hypertension OPSUMIT is an endothelin receptor antagonist (ERA) indicated for the treatment of pulmonary arterial hypertension (PAH, WHO Group I) in adults to reduce the risks of disease progression and hospitalization for PAH. […]
On the market
- Earliest approval on file
- October 18, 2013
- Generic labelers
- 13 labelers
- Pharmacy cost
- Not in the survey
Supply and safety
- Shortage
- No current entry
- Recalls
- 0
Source: FDA drug labels via openFDA (Ambrisentan label of September 3, 2026, Macitentan label of April 11, 2025); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do ambrisentan and macitentan differ on the record?
How each works, in its label's words: Ambrisentan, “Two receptor subtypes, ET A and ET B , mediate the effects of ET-1 in the vascular smooth muscle and endothelium.”; Macitentan, “Endothelin (ET)-1 and its receptors (ET A and ET B ) mediate a variety of deleterious effects, such as vasoconstriction, fibrosis, proliferation, hypertrophy, and inflammation.”
Both are in FDA's class endothelin receptor antagonists.
Both labels carry a boxed warning; the records quote them.
Generics: ambrisentan since 2019; macitentan since 2021 (Drugs@FDA).
| Ambrisentan | Macitentan | |
|---|---|---|
| Labeled for | Pulmonary arterial hypertension | Pulmonary arterial hypertension |
| Pharmacologic class | Endothelin Receptor Antagonist | Endothelin Receptor Antagonist |
| How it works (label) | 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. | Endothelin (ET)-1 and its receptors (ET A and ET B ) mediate a variety of deleterious effects, such as vasoconstriction, fibrosis, proliferation, hypertrophy, and inflammation. |
| Half-life (label) | an trough concentration of ambrisentan at steady-state is about 15% of the mean peak concentration and the accumulation factor is about 1.2 after long-term daily dosing, indicating that the effective half-life of … | n/a |
| Earliest approval on file (Drugs@FDA) | June 15, 2007 | October 18, 2013 |
| First generic approved | March 28, 2019 | April 6, 2021 |
| Generic labelers (NDC) | 12 labelers | 13 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $8.02 per tablet (Ambrisentan 10 mg tablet) | n/a |
| 12-month price change | -18% | n/a |
| Boxed warning | Yes | Yes |
| Shortage now | No current entry | No current entry |
| Recalls recorded | 0 | 0 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 124,133 | 68,840 |
| DEA schedule | none | none |
Source: Drugs@FDA, FDA NDC Directory, CMS NADAC of October 7, 2026, FDA shortages and recalls, FAERS via openFDA (FDA files October 8, 2026)
What next?
- Alternatives to ambrisentan
- every medicine labeled for the same conditions