Reported Reactions

Drugs › Antimalarial

Brand name · Atovaquone and proguanil hydrochloride

Malarone: adverse event reports filed with FDA

1,822 reports list it as a suspect or interacting product, 2004–2026. Class: Antimalarial.

1,822
reports as suspect product
0% of all reports · about 81 a year
26
reports, 12 months to June 2026
20 in the 12 months before
74.6%
marked serious by the reporter
92.5% across the class
1.2%
record death among outcomes, as reported
21 reports · not verified by FDA

1,822 adverse event reports received by FDA list the brand name Malarone (atovaquone and proguanil hydrochloride) as a suspect or interacting product, from January 2004 to May 2026. A further 202 reports list it only as a concomitant medication, and those are not counted in the figures on this page.

In the 12 months to June 2026, 26 reports listed it, up 30% from 20 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 81 reports a year and 0% of the 20,646,523 reports in the database, and 2% of the reports for the antimalarial class. How many people take it is not in the data, so a count is not a rate of occurrence.

Reporters most often recorded diarrhoea (8.7%), nausea (8.1%) and pyrexia (7.6%). A report can list several reactions, so shares add to more than 100%; 388 different terms appear across these reports. Diarrhoea is recorded in 8.7% of these reports, about the same share as in the median antimalarial drug (8%).

74.6% of the reports are marked serious by the reporter (92.5% across the class); 1.2% record death among the outcomes and 23.5% record hospitalisation, as reported. 50.5% of the reports came from consumers, and the largest patient age group is 18 to 44 (29.3%). 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

047Jul 2021: 0Aug 2021: 1Sep 2021: 0Oct 2021: 2Nov 2021: 1Dec 2021: 12022Jan 2022: 0Feb 2022: 1Mar 2022: 7Apr 2022: 3May 2022: 5Jun 2022: 1Jul 2022: 0Aug 2022: 4Sep 2022: 2Oct 2022: 0Nov 2022: 2Dec 2022: 02023Jan 2023: 1Feb 2023: 0Mar 2023: 4Apr 2023: 0May 2023: 1Jun 2023: 0Jul 2023: 2Aug 2023: 3Sep 2023: 0Oct 2023: 1Nov 2023: 2Dec 2023: 22024Jan 2024: 2Feb 2024: 0Mar 2024: 0Apr 2024: 2May 2024: 2Jun 2024: 1Jul 2024: 1Aug 2024: 2Sep 2024: 2Oct 2024: 0Nov 2024: 1Dec 2024: 42025Jan 2025: 1Feb 2025: 2Mar 2025: 2Apr 2025: 0May 2025: 5Jun 2025: 0Jul 2025: 0Aug 2025: 0Sep 2025: 4Oct 2025: 6Nov 2025: 2Dec 2025: 32026Jan 2026: 3Feb 2026: 4Mar 2026: 2Apr 2026: 0May 2026: 2Jun 2026: 0

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

0961912004: 9020042005: 1662006: 1542007: 19120072008: 1572009: 1272010: 10120102011: 1242012: 1042013: 9320132014: 792015: 702016: 5420162017: 622018: 652019: 5320192020: 262021: 122022: 2520222023: 162024: 172025: 2520252026: 11

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Malarone reports recording the termmedian drug in antimalarial

  1. Diarrhoealoose or frequent stools8.7%158
  2. Nauseafeeling sick8.1%147
  3. Pyrexiafever7.6%138
  4. Vomitingbeing sick6.8%124
  5. Malaria6.3%114
  6. Headachehead pain6.1%111
  7. Drug ineffectivethe medicine did not work as expected5.4%99
  8. Dizzinesslight-headedness or unsteadiness5.2%94
  9. Malaisegeneral feeling of being unwell4.8%87
  10. Fatiguetiredness4.6%84
  11. Hallucinationseeing or hearing things that are not there4%72
  12. Rashskin rash3.8%70
  13. Abdominal painstomach or belly pain3.3%60
  14. Astheniaweakness or lack of energy3.3%60
  15. Anxietyanxiety3.2%59
  16. Insomniadifficulty sleeping3.1%56
  17. Drug interactionan interaction between medicines3%55
  18. Urticariahives2.9%53
  19. Pruritusitching2.9%52
  20. Dyspnoeashortness of breath2.7%49
  21. Abnormal dreamsunusual dreams2.3%41
  22. Abdominal pain upperupper stomach pain2.1%39
  23. Drug exposure during pregnancythe medicine was taken during pregnancy2.1%39
  24. Mouth ulcerationmouth ulcers2.1%39
  25. Depressionlow mood2.1%38
  26. Chillschills or shivering2%36
  27. Alopeciahair loss1.8%32
  28. Coughcough1.5%28
  29. Oedema peripheralswelling of the legs, ankles or hands1.5%27
  30. Weight decreasedweight loss1.5%27

Top 30 of 388 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 7 drugs in the antimalarial 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

Death1.2%21
Life-threatening4%72
Hospitalisation (initial or prolonged)23.5%428
Disability5.4%98
Congenital anomaly2.4%44
Other serious50.3%917
Not serious25.4%462

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 92,320 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 20.9%16
2 to 112.2%40
12 to 172.7%50
18 to 4429.3%533
45 to 6420.3%370
65 to 745.8%105
75 and over2.4%44
Age not given36.4%664

Patient sex

Female53.1%968
Male36.8%671
Not given10%183

Who reported

Physician29.6%539
Pharmacist7.8%142
Other health professional10.4%189
Lawyer0.1%2
Consumer or non-health professional50.5%920
Not given1.6%30

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 31.4% of reports give the United States as the country of the event or reporter.

Reason for use recorded

Indication as recorded (MedDRA)ReportsShare
Malaria prophylaxis99054.3%
Malaria18610.2%
Prophylaxis1749.5%
Babesiosis170.9%
Foreign travel80.4%
Lyme disease80.4%

The indication field is filled in by the reporter and is often blank; shares are of all 1,822 reports.

In context

MeasureMalaroneAntimalarialAll reports
Reports as suspect product1,82292,32020,646,523
Share of that pool—2%0%
Reports, latest 12 months26—1,332,454
Marked serious74.6%92.5%57.4%
Death recorded among outcomes, per 1,000 reports1213591
Hospitalisation recorded, per 1,000 reports235288213
Consumer-filed share50.5%17.9%45.8%
Top term, share of reportsDiarrhoea 8.7%median 8%3.1%

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 antimalarial class

DrugName typeReportsLatest 12 monthsMarked serious
Hydroxychloroquinegeneric40,5142,66193.1%
Hydroxychloroquine sulfategeneric24,0181,32497.9%
Plaquenilbrand21,54055486.7%
Quininegeneric1,8588194.5%
Atovaquonegeneric1,82522494.2%
Quinine sulfategeneric7431791.3%

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 Malarone reports

How many adverse event reports has FDA received for Malarone?

1,822 reports list Malarone as a suspect or interacting product in the openFDA FAERS release of 28 Sep 2026, covering reports received through June 2026. 26 of them arrived in the latest 12 months. Another 202 list it only as a concomitant medication.

What reactions are recorded in Malarone reports?

diarrhoea (8.7%), nausea (8.1%), pyrexia (7.6%), vomiting (6.8%) and malaria (6.3%). 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 Malarone was responsible.

How serious are the reports?

74.6% are marked serious by the reporter. Among the outcomes recorded, 1.2% of reports include death and 23.5% 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 (50.5%), physician (29.6%) and other health professional (10.4%). Most reports reach FDA through the manufacturer, which must forward reports it receives.

Are reports for Malarone rising?

26 reports in the 12 months to June 2026, up 30% from 20 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 Malarone 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 Malarone?

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 Malarone as a suspect or interacting product; reports listing it only as a concomitant medication (202) 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.