Pharmacologic class (EPC) · 7 drug pages

Antimalarial: adverse event reports filed with FDA

92,320 reports list a drug in this class as a suspect or interacting product, 2004–2026.

Read first · FDA's statement on these data

Adverse event reports submitted to FDA do not undergo extensive validation or verification. Therefore, a causal relationship cannot be established between product and reactions listed in a report. While a suspected relationship may exist, it is not medically validated and should not be the sole source of information for clinical decision making or other assumptions about the safety or efficacy of a product. Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product. openFDA, FDA

FDA adds: "There is no certainty that the reported event (adverse event or medication error) was actually due to the product. FDA does not require that a causal relationship between a product and event be proven, and reports do not always contain enough detail to properly evaluate an event." The information in these reports "cannot be used to estimate the incidence of these events."

Do not rely on openFDA to make decisions regarding medical care. While we make every effort to ensure that data is accurate, you should assume all results are unvalidated.

Not medical advice. This site counts what was reported to FDA. Questions about a medicine or device belong with a pharmacist or clinician.

92,320
reports across the class: 0.5% of all reports; 4,887
reports, 12 months to June 2026: 6,470 in the 12 months before; 92.5%
marked serious by the reporter: 57.4% across all reports; 7
drugs with a page: brand and generic names counted separately

Antimalarial is a pharmacologic class (an FDA Established Pharmacologic Class) with 7 drug pages on this site. Together those drugs are listed as a suspect or interacting product in 92,320 adverse event reports received by FDA, 0.5% of the database, from January 2004 to June 2026.

4,887 reports arrived in the 12 months to June 2026, down 24% from 6,470 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. 92.5% of the class's reports are marked serious, 13.5% record death among the outcomes and 28.8% record hospitalisation, as reported.

Across the class the reactions recorded most often are drug ineffective (46.8%), rheumatoid arthritis (32.7%) and off label use (24%). The class median share shown beside each term is the middle value across the member drugs; it is the comparison used on every drug page in this class.

The members table is 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."

Drugs in the class

Drug	Name type	Reports	Latest 12 months	Marked serious	Top term recorded
Hydroxychloroquine	generic	40,514	2,661	93.1%	Drug ineffective
Hydroxychloroquine sulfate	generic	24,018	1,324	97.9%	Drug ineffective
PlaquenilHydroxychloroquine sulfate	brand	21,540	554	86.7%	Drug ineffective
Quinine	generic	1,858	81	94.5%	Drug abuse
Atovaquone	generic	1,825	224	94.2%	Drug ineffective
MalaroneAtovaquone and proguanil hydrochloride	brand	1,822	26	74.6%	Diarrhoea
Quinine sulfate	generic	743	17	91.3%	Toxicity to various agents

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."

Reports by month, five years

FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.

Reactions recorded across the class

share of class reports recording the termmedian drug in the class

Drug ineffectivethe medicine did not work as expected46.8%43,249
Rheumatoid arthritisrheumatoid arthritis, an inflammatory joint disease32.7%30,165
Off label useused for a purpose or in a way not on the label24%22,185
Drug intolerancethe medicine was not tolerated23.4%21,634
Painpain, site not specified23.3%21,494
Joint swellinga swollen joint19.9%18,351
Fatiguetiredness19.8%18,240
Contraindicated product administered19.5%17,966
Arthralgiajoint pain17.9%16,545
Abdominal discomfortstomach discomfort17.5%16,182
Rashskin rash17.2%15,863
Alopeciahair loss17.1%15,831
Arthropathy16.2%14,972
Synovitis16.2%14,967
Systemic lupus erythematosuslupus, an autoimmune disease16%14,745
Condition aggravatedthe condition being treated got worse15.3%14,086
Treatment failurethe treatment did not work15.2%14,069
Pemphigus14.9%13,759
Swellingswelling14.6%13,511
Glossodynia13.7%12,614
Hand deformity13.2%12,148
Hypersensitivityan allergic-type reaction13%11,985
Drug hypersensitivityan allergic-type reaction to a medicine12.7%11,708
Hepatic enzyme increasedraised liver enzymes12.4%11,462
Nauseafeeling sick12.4%11,426

Solid bar: share of all class reports. Hollow bar: the median share across the 7 member drugs, the reference used on each member's page. One report can record several terms.

Outcomes, patients and reporters

Outcomes recorded

Death13.5%12,454

Life-threatening12.5%11,548

Hospitalisation (initial or prolonged)28.8%26,616

Disability16.2%14,952

Congenital anomaly5%4,635

Other serious79.9%73,779

Not serious7.5%6,898

Patient age

Under 20.3%281

2 to 110.8%778

12 to 170.9%870

18 to 4420.4%18,800

45 to 6425.4%23,475

65 to 749.2%8,450

75 and over5%4,649

Age not given37.9%35,017

Who reported

Physician23.6%21,826

Pharmacist2.2%2,024

Other health professional54.9%50,662

Lawyer0.1%81

Consumer or non-health professional17.9%16,500

Not given1.3%1,227

Grey bar: all 20,646,523 reports in the database. Outcome flags are as the reporter set them and are not verified by FDA.

Questions about Antimalarial reports

Which drugs are in the Antimalarial class on this site?

Hydroxychloroquine, Hydroxychloroquine sulfate, Plaquenil, Quinine, Atovaquone and Malarone and 1 more. Class membership comes from the pharmacologic class (EPC) on the drug's FDA label.

How many reports does the class have?

92,320 reports through June 2026, 4,887 of them in the latest 12 months. A report listing two drugs of the class counts once for each.

What reactions are recorded most often?

drug ineffective (46.8%), rheumatoid arthritis (32.7%), off label use (24%), drug intolerance (23.4%) and pain (23.3%).

Can the members table be used to rank the drugs?

No. 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." Drugs differ in how many people take them, in the conditions they treat, in time on the market and in how diligently reports are collected.

How do I report an adverse event?

Through FDA MedWatch (Form FDA 3500, or 1-800-FDA-1088) or to the manufacturer. 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 class is the Established Pharmacologic Class most often attached to a drug's reports by openFDA's label harmonisation, or from the NDC Directory where reports carry none. 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.