Ambrisentan Shortage Update: What Patients Need to Know in 2026

For patients living with pulmonary arterial hypertension (PAH), consistent access to ambrisentan (Letairis) is not just important — it is essential. Even a brief gap in treatment can lead to clinical worsening. That is why the ambrisentan shortage that emerged in 2024 caused real anxiety for patients and their care teams. Here is a clear-eyed look at what happened, where things stand in 2026, and how you can protect your supply.

What Happened: The 2024 Ambrisentan Shortage

In May 2024, the American Society of Health-System Pharmacists (ASHP) published a drug shortage bulletin specifically for ambrisentan tablets manufactured by Zydus Pharmaceuticals. The exact reason for Zydus's supply disruption was not publicly disclosed, but shortages of this type typically involve manufacturing capacity issues, quality holds, or supply chain disruptions in active pharmaceutical ingredients.

Importantly, the shortage was manufacturer-specific — not a market-wide supply collapse. Other generic manufacturers including Apotex, Cipla, Mylan, Sun Pharma, and Teva maintained their ambrisentan supply throughout this period, as did Gilead Sciences for brand Letairis. The ASHP updated the bulletin in December 2024 as Zydus reported returning availability.

Current Status in 2026: Is Ambrisentan Still in Shortage?

As of early 2026, ambrisentan is not under an active national FDA shortage. Multiple manufacturers have product available in both 5 mg and 10 mg strengths:

Generic manufacturers with available supply: Apotex, Cipla USA, Mylan, Sun Pharma, Teva, and Zydus

Brand Letairis: Available through certified specialty pharmacies via Gilead Sciences' LEAP program

However, patients may still encounter localized stocking gaps at individual pharmacies. Because ambrisentan treats a rare disease (PAH affects relatively few people), not every pharmacy orders it as a routine stock item. A pharmacy that does not regularly dispense ambrisentan may not have it on the shelf, even when the broader market is well-supplied.

Why PAH Patients Are Especially Vulnerable to Drug Shortages

Most drug shortages are an inconvenience. For PAH patients, they can be dangerous. Pulmonary arterial hypertension is a progressive, life-threatening condition. The right-sided heart must continually pump against elevated pulmonary pressure, and medications like ambrisentan help reduce that pressure. Abruptly stopping an endothelin receptor antagonist without medical guidance can cause rapid hemodynamic deterioration.

This is why PAH specialists consistently recommend that patients:

Never stop ambrisentan without speaking to their doctor first

Keep a small buffer supply when possible (refill early)

Identify backup pharmacies in advance — know where else you could fill your prescription if your primary pharmacy is out

How to Protect Your Ambrisentan Supply

Here are the most effective strategies for protecting your access to ambrisentan:

Refill early. Request your refill 10 to 14 days before running out. This gives you time to address any stocking or prior authorization issues.

Identify backup pharmacies. Know at least two or three pharmacies in your area that stock your medication. Try retail chains for generic or other specialty pharmacies for brand Letairis.

Use medfinder. If you are struggling to locate your supply, medfinder contacts pharmacies near you to identify which ones can fill your prescription. Results are texted to you.

Contact LEAP. Gilead's LEAP program (1-866-664-5327) can help brand Letairis patients navigate access challenges and connect with alternative supply sources.

Tell your PAH specialist immediately. If you cannot fill your medication, alert your doctor right away. They may have bridge samples or emergency supply options and can provide guidance on managing your condition during any gap.

Understanding the Generic Landscape

One of the most important developments for long-term ambrisentan access was the FDA's approval of generic versions in 2019. Multiple manufacturers now produce the medication, which significantly reduces the risk of a market-wide shortage. When any single manufacturer has supply issues (as Zydus did in 2024), patients and pharmacies can turn to other generic producers.

The trade-off is that different pharmacies carry different manufacturers' products. If your usual pharmacy's wholesaler sources primarily from one manufacturer, a shortage at that manufacturer can affect your pharmacy's supply even when others have product. Calling around to find which pharmacies stock a different manufacturer's version can resolve this issue quickly.

The Bottom Line

The 2024 ambrisentan shortage resolved, and multiple manufacturers now maintain supply in 2026. However, localized gaps remain possible and PAH patients must stay proactive. Refill early, identify backup pharmacies, use medfinder to locate supply, and stay in close contact with your specialist. For more practical guidance, see our guide on how to find ambrisentan in stock near you.