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Hydroxychloroquine

Brand names: Plaquenil, Sovuna

Hydroxychloroquine treats lupus and rheumatoid arthritis, and prevents and treats malaria.

Brand namesPlaquenil, Sovuna
Type of medicineAntimalarial and DMARD
Prescription?Prescription
ImportantThis page is general information, not a prescription. Don't start, stop, or change a medicine without talking to your provider or pharmacist.

Overview

It calms the immune system gently. Benefits for lupus and arthritis can take a few months.

What it's used for

  • Lupus
  • Rheumatoid arthritis
  • Malaria (prevention and treatment)

How to take it

  • Take it with food or milk to reduce stomach upset.
  • Get a baseline eye exam and yearly eye checks after 5 years (sooner if at higher risk).

Your dose depends on your health and other medicines. Always follow your prescription label, and ask your pharmacist if anything is unclear.

Side effects

Common side effects

  • Nausea or upset stomach
  • Diarrhea
  • Headache
  • Rash
Call 911Fainting or a fast, irregular heartbeat
Call your provider todayVision changes, trouble reading, or blind spots
Call your provider todayLow blood sugar: shakiness, sweating, or confusion
Call your provider todayMuscle weakness
Call 911A blistering, peeling, or widespread red rash, especially with fever
Call 911Thoughts of suicide or harming yourself. Call or text 988 any time.

Warnings

  • Long-term use can damage the retina; regular eye exams catch it early.
  • Keep it away from children; a small amount can be deadly to a child.

Other medicines, foods, and alcohol

  • Other medicines that affect heart rhythm add to that risk.
  • Antacids lower absorption; separate by 4 hours.
  • Diabetes medicines may need adjusting.

Tell your provider and pharmacist about every medicine, vitamin, and supplement you take.

Pregnancy and breastfeeding

Often continued in pregnancy for lupus. Talk with your provider.

Missed doses, overdose, and storage

If you miss a dose

Take it as soon as you remember, unless it's almost time for your next dose. Then skip the missed dose. Don't take two doses at once.

If someone takes too much

Call Poison Control at 1-800-222-1222 or get help online at poison.org. Call 911 if the person collapses, has a seizure, has trouble breathing, or can't be woken.

Storing it

Store at room temperature, away from heat and moisture (not in the bathroom), and out of reach of children and pets.

Conditions it's used for

Sources

Last updated 2026-11-13.