Reported Reactions

Drugs

Brand name · Mavacamten

Camzyos: adverse event reports filed with FDA

4,686 reports list it as a suspect or interacting product, 2022–2026.

4,686
reports as suspect product
0% of all reports · about 1,149 a year
1,868
reports, 12 months to June 2026
1,212 in the 12 months before
39.4%
marked serious by the reporter
57.4% across all reports
2.5%
record death among outcomes, as reported
117 reports · not verified by FDA

Between June 2022 and June 2026, 4,686 adverse event reports received by FDA list the brand name Camzyos (mavacamten) as a suspect or interacting product. Reports that mention it only as a concomitant medication (96) are left out of every figure here.

In the 12 months to June 2026, 1,868 reports listed it, up 54% from 1,212 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Over its reporting history that is about 1,149 reports a year and 0% of the 20,646,523 reports in the database. How many people take it is not in the data, so a count is not a rate of occurrence.

Reporters most often recorded fatigue (7.1%), product dose omission issue (6.8%) and dyspnoea (6.6%). A report can list several reactions, so shares add to more than 100%; 523 different terms appear across these reports. Fatigue is recorded in 7.1% of these reports, against 3.7% of all reports in the database.

39.4% of the reports are marked serious by the reporter; 2.5% record death among the outcomes and 16.3% record hospitalisation, as reported. 56.9% of the reports came from consumers, and the largest patient age group is 75 and over (25.4%). FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event."

Reports by month, five years

0136272Jul 2021: 0Aug 2021: 0Sep 2021: 0Oct 2021: 0Nov 2021: 0Dec 2021: 02022Jan 2022: 0Feb 2022: 0Mar 2022: 0Apr 2022: 0May 2022: 0Jun 2022: 3Jul 2022: 14Aug 2022: 49Sep 2022: 57Oct 2022: 66Nov 2022: 88Dec 2022: 992023Jan 2023: 75Feb 2023: 81Mar 2023: 78Apr 2023: 59May 2023: 74Jun 2023: 52Jul 2023: 69Aug 2023: 73Sep 2023: 56Oct 2023: 70Nov 2023: 60Dec 2023: 462024Jan 2024: 47Feb 2024: 78Mar 2024: 81Apr 2024: 73May 2024: 86Jun 2024: 72Jul 2024: 62Aug 2024: 78Sep 2024: 80Oct 2024: 98Nov 2024: 76Dec 2024: 1242025Jan 2025: 128Feb 2025: 140Mar 2025: 113Apr 2025: 112May 2025: 104Jun 2025: 97Jul 2025: 73Aug 2025: 81Sep 2025: 93Oct 2025: 115Nov 2025: 113Dec 2025: 1252026Jan 2026: 146Feb 2026: 150Mar 2026: 246Apr 2026: 198May 2026: 256Jun 2026: 272

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

06471,2942022: 37620222023: 79320232024: 95520242025: 1,29420252026: 1,2682026

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Camzyos reports recording the termall reports in the database

  1. Fatiguetiredness7.1%335
  2. Product dose omission issuea dose was missed6.8%317
  3. Dyspnoeashortness of breath6.6%309
  4. Dizzinesslight-headedness or unsteadiness5.9%277
  5. Atrial fibrillationan irregular heart rhythm5.6%263
  6. Product use issuea problem in how the product was used4.9%231
  7. Off label useused for a purpose or in a way not on the label3.5%166
  8. Chest painchest pain3.2%148
  9. Palpitationsawareness of the heartbeat3.1%147
  10. Headachehead pain3%140
  11. Nasopharyngitisa cold3%140
  12. Adverse eventan unwanted medical event, type not specified2.8%129
  13. Peripheral swellingswelling of the arms or legs2.5%118
  14. Weight increasedweight gain2.4%113
  15. Coughcough2.1%99
  16. Urinary tract infectionbladder or urinary infection2.1%98
  17. Adverse drug reactiona harmful or unpleasant reaction reported to a medicine2%92
  18. Falla fall2%92
  19. Hypertensionhigh blood pressure1.9%91
  20. Cardiac failureheart failure1.9%89
  21. Malaisegeneral feeling of being unwell1.9%87
  22. Nauseafeeling sick1.8%85
  23. Hospitalisationadmission to hospital1.8%84
  24. Blood pressure increaseda raised blood pressure reading1.5%69
  25. Diarrhoealoose or frequent stools1.4%65
  26. Chest discomfortchest discomfort1.4%64
  27. Pneumonialung infection1.3%61
  28. Covid-19COVID-19 infection1.3%60

Top 30 of 523 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 share of all reports in the database; 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

Death2.5%117
Life-threatening1.4%66
Hospitalisation (initial or prolonged)16.3%766
Disability0.7%33
Congenital anomaly0%0
Other serious30.6%1,435
Not serious60.6%2,838

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 20,646,523 reports. FDA has not verified any outcome and states that the reports "cannot be used to estimate the incidence of these events."

Patients and reporters

Patient age

Under 20%0
2 to 110.1%3
12 to 170.1%4
18 to 444.7%221
45 to 6421.7%1,018
65 to 7424.7%1,158
75 and over25.4%1,191
Age not given23.3%1,091

Patient sex

Female59.8%2,800
Male26%1,218
Not given14.3%668

Who reported

Physician14.3%672
Pharmacist10%469
Other health professional17.5%822
Lawyer0%0
Consumer or non-health professional56.9%2,667
Not given1.2%56

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 91% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Hypertrophic cardiomyopathy3,98084.9%
Cardiomyopathy260.6%
Cardiac failure30.1%
Atrial fibrillation20%
Cardiac disorder20%
Cardiac failure congestive20%

The indication field is filled in by the reporter and is often blank; shares are of all 4,686 reports.

In context

MeasureCamzyosAll reports
Reports as suspect product4,68620,646,523
Share of that pool—0%
Reports, latest 12 months1,8681,332,454
Marked serious39.4%57.4%
Death recorded among outcomes, per 1,000 reports2591
Hospitalisation recorded, per 1,000 reports163213
Consumer-filed share56.9%45.8%
Top term, share of reportsFatigue 7.1%3.7%

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."

Questions about Camzyos reports

How many adverse event reports has FDA received for Camzyos?

4,686 reports list Camzyos as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 1,868 of them arrived in the latest 12 months. Another 96 list it only as a concomitant medication.

What reactions are recorded in Camzyos reports?

fatigue (7.1%), product dose omission issue (6.8%), dyspnoea (6.6%), dizziness (5.9%) and atrial fibrillation (5.6%). These are MedDRA preferred terms coded from what the reporter described; a report can list several, and a term's presence is not a finding that Camzyos was responsible.

How serious are the reports?

39.4% are marked serious by the reporter. Among the outcomes recorded, 2.5% of reports include death and 16.3% include hospitalisation. FDA has not verified these outcomes and states that the reports "cannot be used to estimate the incidence" of the events.

Who files these reports?

consumer or non-health professional (56.9%), other health professional (17.5%) and physician (14.3%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Camzyos rising?

1,868 reports in the 12 months to June 2026, up 54% from 1,212 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Counts also move with how many people take a product, its time on the market and publicity.

Do these reports show that Camzyos was responsible for these reactions?

No. FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event." The reaction may relate to the condition being treated, to other medicines, or to something else.

Is this a list of the side effects of Camzyos?

No. It is a count of what was reported to FDA. The adverse reactions observed in clinical studies are printed on the FDA-approved label, which a pharmacist or clinician can go through with you.

How do I report an adverse event?

Consumers and health professionals can report to FDA through MedWatch (Form FDA 3500 online, or 1-800-FDA-1088), or to the manufacturer, which must pass reports on. See the guide on how to report.

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 Camzyos as a suspect or interacting product; reports listing it only as a concomitant medication (96) 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.

Drug data (FAERS) through 30 Jun 2026; device data (MAUDE) through 31 Aug 2026. Not medical advice.