Letairis: adverse event reports filed with FDA

49,743

reports as suspect product

0.2% of all reports · about 2,630 a year

58

reports, 12 months to June 2026

74 in the 12 months before

46.6%

marked serious by the reporter

72.7% across the class

10.8%

record death among outcomes, as reported

5,397 reports · not verified by FDA

Reports by month, five years

Reports by the month FDA received them. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.

By year received

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Letairis reports recording the termmedian drug in endothelin receptor antagonist

1. Dyspnoeashortness of breath15.7%7,802
2. Headachehead pain6.7%3,344
3. Deaththe patient died; cause not stated by this term6.3%3,136
4. Dizzinesslight-headedness or unsteadiness5.2%2,585
5. Fluid retentionthe body holding extra fluid4.7%2,354
6. Fatiguetiredness4.7%2,351
7. Oedema peripheralswelling of the legs, ankles or hands4.4%2,180
8. Pneumonialung infection4.3%2,141
9. Oedemaswelling from fluid4.1%2,048
10. Malaisegeneral feeling of being unwell4%1,999
11. Nasal congestiona blocked nose3.9%1,961
12. Nauseafeeling sick3.7%1,826
13. Coughcough3.7%1,822
14. Unevaluable eventthe event could not be assessed3.5%1,752
15. Diarrhoealoose or frequent stools3.4%1,672
16. Peripheral swellingswelling of the arms or legs3.2%1,577
17. Chest painchest pain2.5%1,255
18. Swellingswelling2.4%1,200
19. Nasopharyngitisa cold2.4%1,173
20. Hypotensionlow blood pressure2.1%1,068
21. Syncopefainting2.1%1,048
22. Vomitingbeing sick2.1%1,039
23. Astheniaweakness or lack of energy2%983
24. Weight increasedweight gain1.8%904
25. Cardiac failure congestivecongestive heart failure1.7%865
26. Pulmonary arterial hypertension1.7%863
27. Flushingsudden reddening or warmth of the skin1.7%861
28. Anaemialow red blood cells1.7%840
29. Pain in extremitypain in an arm or leg1.7%825
30. Painpain, site not specified1.6%815

Top 30 of 1,597 MedDRA preferred terms recorded across these reports, with a plain-language gloss where one is available. One report can record several terms. The hollow bar is the median share across the 6 drugs in the endothelin receptor antagonist class; it describes the reports, not the patients. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Outcomes recorded

Outcome flags as the reporter set them; a report can carry several, and "other serious" is FDA's own category for serious reports outside the named outcomes. Grey bar: all 192,634 reports in the class. FDA has not verified any outcome and states that the reports "cannot be used to estimate the incidence of these events."

Patients and reporters

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 99.9% of reports give the United States as the country of the event or reporter.

Reason for use recorded

The indication field is filled in by the reporter and is often blank; shares are of all 49,743 reports.

Drugs most often listed in the same reports

Other products listed in reports where Letairis is a suspect product, whatever their own role. Co-listing means the two were recorded together; it says nothing about either product's part in the event. Only the 2,500 most-reported names are counted here.

In context

Shares are of reports, not of patients treated. The number of people taking a product is not in the data, so none of these figures is a rate, and differences between columns reflect who takes a product, who reports and how long it has been sold. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Other drugs in the endothelin receptor antagonist class

Ordered by report count for navigation only. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic." A brand and its generic are separate rows because reporters name them separately.

Where this comes from. Counts are built from the openFDA Drug Adverse Event (FAERS) bulk export released 28 Sep 2026, which holds reports FDA received through 30 Jun 2026. Drug names are as reported, resolved to the brand or generic name on the FDA label where openFDA's harmonisation matched them; classes are the pharmacologic class (EPC) from the label and the National Drug Code Directory of 17 Sep 2026. A report counts here when it lists Letairis as a suspect or interacting product; reports listing it only as a concomitant medication (13,149) are excluded. No report narrative, lot number, patient detail or reporter identity is published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.