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hydroxychloroquine vs leflunomide

Side-by-side comparison of hydroxychloroquine and leflunomide Data from FDA drug databases (Orange Book, NDC Directory, recalls, shortages) covering 20,000+ approved drugs, plus CMS pricing; see our methodology.

Drug Class
hydroxychloroquine Disease-Modifying Antirheumatic Drug (DMARD)
leflunomide Disease-Modifying Antirheumatic Drug (DMARD)
Type
hydroxychloroquine Prescription
leflunomide Prescription
Summary
hydroxychloroquine

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.

leflunomide

Leflunomide is a drug that can help reduce the symptoms of rheumatoid arthritis. It works by slowing down the body's immune system.

What It Treats
hydroxychloroquine

This medicine can treat uncomplicated malaria caused by certain parasites. It can also prevent malaria in areas where the parasites are not resistant to the drug. Hydroxychloroquine also treats rheumatoid arthritis, systemic lupus erythematosus, and chronic discoid lupus erythematosus.

leflunomide

Leflunomide treats active rheumatoid arthritis in adults. Rheumatoid arthritis is a disease that causes pain, swelling, and stiffness in the joints. This medicine can help reduce these symptoms.

How It Works
hydroxychloroquine

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.

leflunomide

Leflunomide is a pyrimidine synthesis inhibitor. This means it blocks a certain process in your body. By blocking this process, it can reduce inflammation and slow down the damage to your joints.

Common Side Effects
hydroxychloroquine
  • Nausea
  • Vomiting
  • Diarrhea
  • Abdominal pain
  • Fatigue
leflunomide
  • Diarrhea
  • Respiratory infection
  • Nausea
  • Headache
  • Rash
FAERS Reports
hydroxychloroquine
  • The medicine did not work 20,457
  • Using the medicine for a condition it is not approved for 15,128
  • Rheumatoid arthritis 12,921
  • Pain 10,409
  • Joint pain 9,276
leflunomide
  • The medicine is not working 36,982
  • Rheumatoid arthritis 24,921
  • Pain 20,055
  • Joint pain 16,943
  • Cannot tolerate the medicine 15,586
Serious Warnings
hydroxychloroquine

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.

leflunomide

This drug can cause serious harm to an unborn baby. If you are pregnant or could become pregnant, you should not take this medicine. This drug can also cause serious liver problems. If you have liver problems, you should not take this medicine. Your doctor will monitor your liver with blood tests.

Pregnancy
hydroxychloroquine

Tell your doctor if you are pregnant or plan to become pregnant. This drug can cross the placenta, but studies haven't shown a risk of major birth defects. Talk to your doctor about the risks and benefits of taking this medicine while pregnant. Hydroxychloroquine passes into breast milk. Talk to your doctor about breastfeeding while taking this medicine.

leflunomide

Do not take leflunomide if you are pregnant. It can cause birth defects. If you are breastfeeding, you should stop while taking this medicine.

Also Compare — Nearby Drugs

How to Read This hydroxychloroquine vs leflunomide Comparison

hydroxychloroquine is classified in the Disease-Modifying Antirheumatic Drug (DMARD) drug class, while leflunomide sits within the Disease-Modifying Antirheumatic Drug (DMARD) class. Because both drugs share the same classification, they are often considered interchangeable in theory — but clinical outcomes rarely track that cleanly. Both drugs are prescription-only, so a licensed provider must authorize use.

Adverse event totals above are pulled from the FDA's Adverse Event Reporting System (FAERS). For these top-ranked reactions alone, hydroxychloroquine has 68,191 submissions while leflunomide has 114,487. Those figures reflect cumulative reporting volume — not per-patient risk — so older, widely dispensed drugs typically look worse on count alone. No direct interaction between these two drugs is listed in our FDA-derived dataset, though co-prescription still warrants pharmacist review. Serious warnings, pregnancy guidance, and contraindications can differ even when indications overlap.

A table cannot substitute for clinical judgment. Effectiveness, tolerability, drug-drug interactions with your other medications, kidney and liver function, pregnancy status, insurance formulary, and price all feed into a decision that only a licensed prescriber can make responsibly. Data here is sourced from FDA Structured Product Labels (SPL) and FAERS, both of which update as manufacturers and clinicians submit new information. This page is for educational purposes only, is not medical advice, and should not be used to self-switch between hydroxychloroquine and leflunomide — always consult your physician or pharmacist first.

Important: This comparison is for informational purposes only. Drug effects vary between individuals. Always consult your doctor or pharmacist for personalized medical advice.