Reported Reactions

Drugs › Androgen receptor inhibitor

Brand name · Enzalutamide

Xtandi: adverse event reports filed with FDA

43,710 reports list it as a suspect or interacting product, 2012–2026. Class: Androgen receptor inhibitor. Also reported as Xtandi 40mg.

43,710
reports as suspect product
0.2% of all reports · about 3,161 a year
1,114
reports, 12 months to June 2026
1,194 in the 12 months before
54.2%
marked serious by the reporter
63.3% across the class
19.2%
record death among outcomes, as reported
8,397 reports · not verified by FDA

Between September 2012 and June 2026, 43,710 adverse event reports received by FDA list the brand name Xtandi (enzalutamide) as a suspect or interacting product. Reports that mention it only as a concomitant medication (3,028) are left out of every figure here.

In the 12 months to June 2026, 1,114 reports listed it, close to the 1,194 of 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 3,161 reports a year and 0.2% of the 20,646,523 reports in the database, and 70.7% of the reports for the androgen receptor inhibitor class. How many people take it is not in the data, so a count is not a rate of occurrence.

The MedDRA terms listed most often are fatigue (18.5%), death (13.1%) and malignant neoplasm progression (10.1%). A report can list several reactions, so shares add to more than 100%; 1,621 different terms appear across these reports. Fatigue is recorded in 18.5% of these reports, a larger share than in the median androgen receptor inhibitor drug (6.4%).

54.2% of the reports are marked serious by the reporter (63.3% across the class); 19.2% record death among the outcomes and 13.9% record hospitalisation, as reported. 70.6% of the reports came from consumers, and the largest patient age group is 75 and over (32.5%). 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

0195390Jul 2021: 98Aug 2021: 87Sep 2021: 330Oct 2021: 83Nov 2021: 100Dec 2021: 1012022Jan 2022: 73Feb 2022: 109Mar 2022: 90Apr 2022: 64May 2022: 77Jun 2022: 94Jul 2022: 92Aug 2022: 83Sep 2022: 390Oct 2022: 82Nov 2022: 91Dec 2022: 782023Jan 2023: 54Feb 2023: 68Mar 2023: 97Apr 2023: 65May 2023: 83Jun 2023: 70Jul 2023: 84Aug 2023: 50Sep 2023: 291Oct 2023: 64Nov 2023: 66Dec 2023: 532024Jan 2024: 64Feb 2024: 96Mar 2024: 61Apr 2024: 73May 2024: 65Jun 2024: 58Jul 2024: 72Aug 2024: 74Sep 2024: 345Oct 2024: 74Nov 2024: 98Dec 2024: 732025Jan 2025: 68Feb 2025: 72Mar 2025: 78Apr 2025: 80May 2025: 77Jun 2025: 83Jul 2025: 119Aug 2025: 204Sep 2025: 85Oct 2025: 82Nov 2025: 89Dec 2025: 852026Jan 2026: 60Feb 2026: 80Mar 2026: 74Apr 2026: 99May 2026: 72Jun 2026: 65

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

04,3488,6952012: 22320122013: 2,4472014: 4,22520142015: 5,4882016: 7,15720162017: 8,6952018: 5,63320182019: 2,0272020: 1,37620202021: 1,3462022: 1,32320222023: 1,0452024: 1,15320242025: 1,1222026: 4502026

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Xtandi reports recording the termmedian drug in androgen receptor inhibitor

  1. Fatiguetiredness18.5%8,100
  2. Deaththe patient died; cause not stated by this term13.1%5,728
  3. Drug ineffectivethe medicine did not work as expected8.1%3,540
  4. Astheniaweakness or lack of energy6.9%3,024
  5. Hot flusha hot flush6.1%2,684
  6. Decreased appetitereduced appetite6.1%2,654
  7. Nauseafeeling sick6.1%2,652
  8. Dizzinesslight-headedness or unsteadiness5.4%2,363
  9. Diarrhoealoose or frequent stools5%2,196
  10. Underdoseless than the intended dose4.1%1,774
  11. Back painback pain4%1,737
  12. Arthralgiajoint pain3.6%1,593
  13. Constipationconstipation3.2%1,396
  14. Weight decreasedweight loss3.1%1,360
  15. Headachehead pain2.9%1,272
  16. Painpain, site not specified2.8%1,206
  17. Falla fall2.7%1,196
  18. Malaisegeneral feeling of being unwell2.7%1,178
  19. Dysphagiadifficulty swallowing2.7%1,172
  20. Peripheral swellingswelling of the arms or legs2.5%1,102
  21. Insomniadifficulty sleeping2.5%1,090
  22. Dyspnoeashortness of breath2.4%1,067
  23. Vomitingbeing sick2.1%928
  24. Drug dose omissiona dose was missed2.1%906
  25. Pain in extremitypain in an arm or leg2%880
  26. Abdominal discomfortstomach discomfort1.8%790
  27. Myalgiamuscle pain1.8%773
  28. Off label useused for a purpose or in a way not on the label1.7%745

Top 30 of 1,621 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 5 drugs in the androgen receptor inhibitor 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

Death19.2%8,397
Life-threatening0.8%349
Hospitalisation (initial or prolonged)13.9%6,097
Disability0.4%194
Congenital anomaly0%5
Other serious34.6%15,104
Not serious45.8%20,008

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 61,805 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

Patient age

Under 20%1
2 to 110%1
12 to 170%0
18 to 440.1%42
45 to 647.3%3,196
65 to 7416.6%7,246
75 and over32.5%14,213
Age not given43.5%19,011

Patient sex

Female0.6%242
Male97.2%42,497
Not given2.2%971

Who reported

Physician12.5%5,471
Pharmacist5%2,166
Other health professional11.2%4,891
Lawyer0%19
Consumer or non-health professional70.6%30,875
Not given0.7%288

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 83.1% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Prostate cancer22,43751.3%
Hormone-refractory prostate cancer5,12311.7%
Prostate cancer metastatic2,3045.3%
Neoplasm prostate3690.8%
Neoplasm malignant2770.6%
Hormone-dependent prostate cancer2090.5%

The indication field is filled in by the reporter and is often blank; shares are of all 43,710 reports.

Drugs most often listed in the same reports

Drug (any role in the report)ReportsShare of Xtandi reports
Lupron2,4895.7%
Prednisone2,0544.7%
Aspirin2,0494.7%
Lisinopril1,4283.3%
Xgeva1,3093%
Tamsulosin1,1902.7%
Atorvastatin1,1802.7%
Calcium1,1132.5%
Amlodipine1,0232.3%
Metformin1,0142.3%

Other products listed in reports where Xtandi 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

MeasureXtandiAndrogen receptor inhibitorAll reports
Reports as suspect product43,71061,80520,646,523
Share of that pool—70.7%0.2%
Reports, latest 12 months1,114—1,332,454
Marked serious54.2%63.3%57.4%
Death recorded among outcomes, per 1,000 reports19218891
Hospitalisation recorded, per 1,000 reports139201213
Consumer-filed share70.6%63.1%45.8%
Top term, share of reportsFatigue 18.5%median 6.4%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."

Other drugs in the androgen receptor inhibitor class

DrugName typeReportsLatest 12 monthsMarked serious
Enzalutamidegeneric10,81142092.7%
Bicalutamidegeneric2,97818493.5%
Casodexbrand2,9672486%
Winlevibrand1,3392452.7%

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.

Questions about Xtandi reports

How many adverse event reports has FDA received for Xtandi?

43,710 reports list Xtandi as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 1,114 of them arrived in the latest 12 months. Another 3,028 list it only as a concomitant medication.

What reactions are recorded in Xtandi reports?

fatigue (18.5%), death (13.1%), malignant neoplasm progression (10.1%), drug ineffective (8.1%) and prostatic specific antigen increased (7.7%). 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 Xtandi was responsible.

How serious are the reports?

54.2% are marked serious by the reporter. Among the outcomes recorded, 19.2% of reports include death and 13.9% 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 (70.6%), physician (12.5%) and other health professional (11.2%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Xtandi rising?

1,114 reports in the 12 months to June 2026, close to the 1,194 of 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 Xtandi 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 Xtandi?

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 Xtandi as a suspect or interacting product; reports listing it only as a concomitant medication (3,028) 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.