Prescription medication · Disease-Modifying Antirheumatic Drug (DMARD)

hydroxychloroquine

Also sold as Plaquenil. This medicine can treat uncomplicated malaria caused by certain parasites.

Data updated 2026-05-15

71,900
FDA reportsOften reported
7
InteractionsFew interactions
In shortage
FDA status

What the data shows

hydroxychloroquine (Plaquenil) is a prescription Disease-Modifying Antirheumatic Drug (DMARD), more reported than most tracked drugs (71,900 FDA reports), with 7 documented drug interactions.

Reporting volume reflects how widely a drug is used and studied, not how dangerous it is, a FAERS report documents a temporal association, never proof of cause.

hydroxychloroquine (Plaquenil) is a prescription Disease-Modifying Antirheumatic Drug (DMARD). This medicine can treat uncomplicated malaria caused by certain parasites.

Hydroxychloroquine is a drug used to treat or prevent malaria, and to treat certain autoimmune diseases. It works by interfering with the immune system and by killing malaria parasites.

Drug Shortage Alert

hydroxychloroquine is currently listed as to be discontinued by the FDA. Affected manufacturer: Teva Pharmaceuticals USA, Inc..

View all drug shortages →

Drug Pricing (NADAC)

Generic Price

$0.17/unit

Generic Available

Yes (11 manufacturers)

Pricing data from NADAC (CMS), effective December 18, 2024. Compare all drug costs →

NADAC price trail: HYDROXYCHLOROQUINE 100 MG TAB

Same CMS presentation as the headline generic unit price above (2 effective dates). Adjacent % compares consecutive NADAC releases for this description only, not a patient out-of-pocket quote. Latest step: -1.3% vs prior release.

Effective NADAC / unit vs prior NDCs
October 23, 2024 $0.1706/EA - 1
December 18, 2024 $0.1684/EA -1.3% 1
View Alternatives → Compare with Another Drug → Full Side Effects Report →

What it does

This medicine can treat uncomplicated malaria caused by certain parasites.

Common side effects

Nausea, Vomiting, Diarrhea

Key warnings

This drug can cause heart problems, including a weakened heart muscle and irregular heartbeats.

The sections below are summarized in plain English from hydroxychloroquine's FDA-approved prescribing information. They describe what the official label says, and are not personal medical advice.

How It Works

Hydroxychloroquine is an antimalarial and antirheumatic drug. It is thought to work by interfering with the immune system's activity. It also stops the growth of malaria parasites in red blood cells.

Side Effects (from patient reports)

Based on 71,900 FDA adverse event reports.

Most-reported reactions

Adverse reactions in FAERS for hydroxychloroquine, by number of reports

reports

What this shows Bars show how often each reaction was reported, not how likely it is to happen, a report records a temporal association, never proof that the drug caused it.

Source FDA Adverse Event Reporting System (FAERS) As of 2025

Reports over time

Adverse-event reports filed for hydroxychloroquine each year to the FDA Adverse Event Reporting System (FAERS).

05,00010,00015,000 20042007201020132016201920222025 5,936

Year-to-year volume tracks usage, prescribing, and scrutiny, not a change in per-patient risk. Source: FDA FAERS.

Where hydroxychloroquine sits

hydroxychloroquine has more FDA adverse-event reports than 80% of the drugs FAERS tracks. A high position reflects how widely a drug is used and watched, not how dangerous it is.

fewest reports most reports

Percentile across all drugs PlainMeds tracks by FAERS report volume. The dot is hydroxychloroquine; the line is the median (50th percentile).

FDA Adverse Event Report Analysis

Detailed analysis of 71,900 reports from the FDA Adverse Event Reporting System (FAERS). Reports span 2004–2025.

Total Reports

71,900

Reports Mentioning Death

7,814

10.9% of reports — not proof of cause

Hospitalization Reports

20,530

Top Indication

Rheumatoid Arthritis

Gender Distribution

Female 48,695 (78%)
Male 13,464 (22%)

Age Distribution

0–17 2,244
18–44 13,170
45–64 19,883
65–74 8,915
75+ 4,426

Most Reported Adverse Reactions (FAERS)

# Reaction Reports
3 RHEUMATOID ARTHRITIS 12,921
4 PAIN 10,409
5 ARTHRALGIA 9,276
7 FATIGUE 8,853
8 JOINT SWELLING 8,528
9 RASH 7,370
10 CONDITION AGGRAVATED 7,013
11 SYNOVITIS 6,692
12 NAUSEA 6,584
13 CONTRAINDICATED PRODUCT ADMINISTERED 6,430
14 TREATMENT FAILURE 6,014
15 ALOPECIA 5,939
16 HEADACHE 5,900
17 ABDOMINAL DISCOMFORT 5,881
18 ARTHROPATHY 5,825

Reactions in Death Reports

SYSTEMIC LUPUS ERYTHEMATOSUS 1,618
RHEUMATOID ARTHRITIS 1,595
GLOSSODYNIA 1,577
GENERAL PHYSICAL HEALTH DETERIORATION 1,575
JOINT SWELLING 1,571
TYPE 2 DIABETES MELLITUS 1,555
HAND DEFORMITY 1,537
INFUSION RELATED REACTION 1,535
FATIGUE 1,520
FIBROMYALGIA 1,518

Reactions in Hospitalization Reports

RHEUMATOID ARTHRITIS 3,601
PAIN 3,570
FATIGUE 3,397
ARTHRALGIA 3,387
CONDITION AGGRAVATED 3,134
RASH 3,054
JOINT SWELLING 3,006
SYNOVITIS 3,005
ARTHROPATHY 2,919
NAUSEA 2,876

Source: FDA FAERS (Adverse Event Reporting System) Reports are voluntary and do not establish causation

Serious Warnings

This drug can cause heart problems, including a weakened heart muscle and irregular heartbeats. It can also cause irreversible damage to your retina, so regular eye exams are needed. This medicine can also cause serious skin reactions. If you have psoriasis or porphyria, talk to your doctor before taking this medicine. It can also cause liver and kidney problems.

Known Drug Interactions

moderate chloroquine

( 7 ) 7.1 Drugs Prolonging QT Interval and Other Arrhythmogenic Drugs Hydroxychloroquine sulfate tablets prolongs the QT interval. There may be an increased risk of inducing ventricular arrhythmias if hydroxychloroquine sulfate tablets are used concomitantly with other arrhythmogenic drugs. Therefore, hydroxychloroquine sulfate tablets are not recommended in patients taking other drugs that have the potential to prolong the QT interval or are arrhythmogenic [see Warnings and Precautions (5.1) ].

Mechanism: Both of these drugs can change the electrical rhythm of your heart. Taking them together increases the risk of a dangerous irregular heartbeat.

moderate cimetidine

7.8 Cimetidine Concomitant use of cimetidine resulted in a 2-fold increase of exposure of chloroquine, which is structurally related to hydroxychloroquine. Interaction of cimetidine with hydroxychloroquine cannot be ruled out. Avoid concomitant use of cimetidine.

Mechanism: Cimetidine can slow down how your body breaks down hydroxychloroquine, which can double the amount of the drug in your system. This makes side effects much more likely.

moderate heparin

7.2 Platelet Inhibitors Drugs such as NSAIDS (including salicylic acid, ibuprofen, indomethacin, and celecoxib), dextran, phenylbutazone, thienopyridines, dipyridamole, hydroxychloroquine, glycoprotein IIb/IIIa antagonists (including abciximab, eptifibatide, and tirofiban), and others that interfere with platelet-aggregation reactions (the main hemostatic defense of heparinized patients) may induce bleeding and should be used with caution in patients receiving heparin sodium.

Mechanism: Hydroxychloroquine can interfere with how blood cells stick together to stop bleeding. When taken with a blood thinner like heparin, it increases the chance of serious bleeding.

moderate remdesivir

7 DRUG INTERACTIONS 7.1 Effects of Other Drugs on VEKLURY Due to potential antagonism based on data from cell culture experiments, concomitant use of VEKLURY with chloroquine phosphate or hydroxychloroquine sulfate is not recommended [see Warnings and Precautions (5.3) and Microbiology (12.4) ].

Mechanism: Hydroxychloroquine can interfere with how remdesivir works against the virus. This means the antiviral treatment might not be able to fight the infection effectively.

7.5 Methotrexate Concomitant use of hydroxychloroquine sulfate tablets and methotrexate may increase the incidence of adverse reactions.

Mechanism: Using these two medications at the same time can make it more likely that you will experience side effects.

Check all your medications →

This is a plain-language summary of FDA-label interaction records and does not provide individual medication-combination directions.

Common Questions

What should I do if I experience vision changes while taking this medication?
Contact your doctor immediately. Vision changes can be a sign of retinal damage.
Can I take this medication with other medications?
Talk to your doctor about all the medications you take, including over-the-counter drugs and supplements. Some drugs can interact with hydroxychloroquine.
How long does it take for this medication to start working for rheumatoid arthritis?
It may take several weeks to months to see the full effect of this medication for rheumatoid arthritis.
Can this medication cure lupus?
No, this medication cannot cure lupus, but it can help manage the symptoms.
What should I do if I develop a rash while taking this medication?
Contact your doctor. A rash could be a sign of a serious skin reaction.
Is it safe to drink alcohol while taking this medication?
Talk to your doctor about alcohol consumption while taking this medication.
Can this medication affect my blood sugar?
Yes, this medication can lower blood sugar levels. If you have diabetes, monitor your blood sugar closely.
Will this medication protect me from all types of malaria?
No, this medication is not recommended in areas where malaria parasites are resistant to chloroquine or hydroxychloroquine.
Can I stop taking this medication if I feel better?
Do not stop taking this medication without talking to your doctor. Your symptoms may return if you stop too soon.
Are there any long-term side effects I should be aware of?
Long-term use of this medication can increase the risk of retinal damage. Regular eye exams are important.
What are the common side effects of hydroxychloroquine?
The registry lists Nausea, Vomiting, Diarrhea, Abdominal pain, Fatigue among the most-reported FAERS reaction terms for hydroxychloroquine. The compiled record contains 71,900 FDA adverse-event reports. These counts are not an individual symptom assessment.
Does hydroxychloroquine interact with other medications?
The registry has 7 documented interaction rows for hydroxychloroquine. Notable source-record pairings include chloroquine, cimetidine, heparin. These rows are not a complete medication review.
What drug class is hydroxychloroquine?
hydroxychloroquine belongs to the Disease-Modifying Antirheumatic Drug (DMARD) drug class. It requires a prescription (Rx). This medicine can treat uncomplicated malaria caused by certain parasites.
What pregnancy or breastfeeding source fields are listed for hydroxychloroquine?
The FDA label for hydroxychloroquine contains product-specific pregnancy or breastfeeding language. PlainMeds does not apply that source text to an individual.
Is hydroxychloroquine currently in shortage?
Yes, hydroxychloroquine is currently listed as to be discontinued by the FDA. Affected manufacturer: Teva Pharmaceuticals USA, Inc.. Visit the FDA Drug Shortages database for the latest updates.

Other drugs grouped near hydroxychloroquine - same-class peers and common alternatives.

Compare hydroxychloroquine vs abatacept side-by-side →

Compare beyond drug class

Nationwide peers by FAERS volume & death-report share

Two PlainMeds-derived comparison paths for hydroxychloroquine: nearest FDA FAERS report volume and nearest death-report share among drugs with at least 1,000 logged reports, excluding same-class neighbors listed above. Counts reflect reporting volume, not proven individual harm.

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What the FDA Data Shows for hydroxychloroquine

The FDA label for hydroxychloroquine (sold under brand names such as Plaquenil) classifies it as a prescription-only medication in the Disease-Modifying Antirheumatic Drug (DMARD) class. This medicine can treat uncomplicated malaria caused by certain parasites. Official labeling lists 6 commonly reported side effects, including Nausea, Vomiting, Diarrhea.

Post-market surveillance from the FDA Adverse Event Reporting System (FAERS) captures real-world experience. For this drug, FAERS contains 71,900 voluntary reports. The database also lists 7 documented drug interactions derived from FDA labeling, with the top-flagged interaction rated moderate severity. NADAC pricing from CMS shows a generic unit cost of $0.17.

Report counts do not establish causation, a FAERS entry documents a temporal association, not proof that the drug produced the outcome. Widely prescribed medications naturally accumulate more reports than niche therapies, so raw totals must be interpreted alongside total exposure. Shortage status, recall history, and patent information are separate source-record fields. This page is a public FDA/CMS registry and does not provide medical, treatment, substitution, or medication-change directions.

Data Sources

Drug labeling: FDA Drug Labels (SPL/DailyMed). Adverse events: FDA Adverse Event Reporting System (FAERS). Pricing: CMS National Average Drug Acquisition Cost (NADAC). Shortage status: FDA Drug Shortages Database.

FAERS reports are voluntary and do not establish causation. Drug interactions are derived from FDA labeling and clinical references. This registry does not provide medication decisions.

Last updated: October 9, 2025

PlainMeds is rendered directly from FDA openFDA/FAERS extracts, DailyMed labels, and CMS drug-pricing files, no number is typed in by an editor. FAERS counts, recalls, shortages, and price figures on this page are queried live from those federal extracts. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-05-15. Primary sources: openFDA / FAERS, DailyMed and CMS Part B ASP.

Data currency: FDA FAERS adverse-event reports through 2025, CMS NADAC acquisition-cost pricing effective December 2024, compiled from the source snapshot dated . See our methodology for per-source dates and refresh cadence. Spot a figure that looks wrong? Report a data issue.

All federal data sources used on this page