Hydroxychloroquine

Generic Name: Hydroxychloroquine

Brand Names: Plaquenil

Hydroxychloroquine is used to treat lupus, rheumatoid arthritis, and malaria. It is available as Plaquenil and is commonly prescribed in the immunology category.

ImmunologyRheumatologyAntimalarials

Drug Class

Antimalarial / Conventional Synthetic Disease-Modifying Antirheumatic Drug (csDMARD)

Pregnancy

Category C — Hydroxychloroquine crosses the placenta. Decades of use in pregnancy for systemic lupus erythematosus have not shown an increased risk of fetal malformations, and current rheumatology guidelines recommend continuing it during pregnancy in patients with lupus to reduce disease flares and adverse pregnancy outcomes.

Available Forms

Oral tablet (200 mg hydroxychloroquine sulfate, equivalent to 155 mg base)

What It's Used For

Hydroxychloroquine is prescribed to treat:

• Lupus, rheumatoid arthritis, and malaria • Various related conditions in the immunology category • Associated symptoms and complications

It is an important medication that helps manage these conditions effectively.

Dosage Quick Reference

These are general dosage guidelines. Your doctor will determine the appropriate dose for your specific situation.

Condition	Starting Dose	Maintenance Dose
Rheumatoid arthritis	400–600 mg/day in 1–2 divided doses with food	200–400 mg/day; do not exceed 5 mg/kg actual body weight per day
Systemic lupus erythematosus	400 mg once or twice daily	200–400 mg/day; do not exceed 5 mg/kg actual body weight per day
Cutaneous lupus	200–400 mg/day	200–400 mg/day with annual ophthalmologic monitoring
Malaria prophylaxis	400 mg once weekly, starting 1–2 weeks before travel	400 mg once weekly during travel and for 4 weeks after return
Acute uncomplicated malaria	800 mg, then 400 mg at 6, 24, and 48 hours	Total 2 g over 3 days

Side Effects

Common side effects may include:

• Nausea or stomach upset • Headache • Dizziness or lightheadedness • Fatigue or tiredness • Mild rash or itching

Serious side effects (seek immediate medical attention):

• Severe allergic reactions (rash, hives, swelling, difficulty breathing) • Unusual bleeding or bruising • Severe stomach pain • Signs of liver problems (yellowing of skin/eyes, dark urine) • Chest pain or irregular heartbeat • Severe dizziness or fainting • Signs of serious adverse effects

Drug Interactions

Hydroxychloroquine has several clinically meaningful interactions, particularly involving cardiac conduction and blood glucose.

QT-prolonging agents (e.g., azithromycin, fluoroquinolones, ondansetron, citalopram, methadone): Hydroxychloroquine prolongs the QT interval, and combinations with other QT-prolonging drugs raise the risk of torsades de pointes. Obtain a baseline ECG when combining and avoid co-use in patients with congenital long QT syndrome.
Insulin and oral hypoglycemics (e.g., metformin, sulfonylureas): Hydroxychloroquine improves insulin sensitivity and may cause hypoglycemia. Monitor glucose closely and consider lowering antidiabetic medication doses, especially when starting therapy.
Digoxin: Hydroxychloroquine increases serum digoxin levels. Recheck digoxin levels within 1–2 weeks of starting therapy and adjust dose to maintain a therapeutic level.
Cyclosporine and tacrolimus: Hydroxychloroquine can raise levels of these immunosuppressants. Monitor trough levels and renal function in transplant or autoimmune patients.
Antacids and kaolin: Reduce hydroxychloroquine absorption. Separate administration by at least 4 hours.
Methotrexate: Combination is common in rheumatoid arthritis and is generally well tolerated. Monitor liver enzymes and complete blood count routinely.

Additional Information

What is Hydroxychloroquine?

Hydroxychloroquine (generic name: Hydroxychloroquine) is a medication primarily used to treat lupus, rheumatoid arthritis, and malaria. It is marketed under the brand name(s) Plaquenil and belongs to the Immunology category of medications.

How Does Hydroxychloroquine Work?

Hydroxychloroquine works through several mechanisms to provide therapeutic benefits:

Acts on specific receptors or pathways in the body
Modulates biological processes related to the treated condition
Provides symptom relief and improves quality of life
Helps manage the underlying condition effectively
Works best when combined with appropriate lifestyle modifications

The medication is designed to target the specific pathways involved in lupus, rheumatoid arthritis, and malaria, making it an effective treatment option.

Common Uses

Primary Indications

Hydroxychloroquine is commonly prescribed for:

Lupus, rheumatoid arthritis, and malaria: The main indication for this medication
Related Conditions: Associated symptoms and complications
Prevention: May help prevent progression of certain conditions
Symptom Management: Reduces discomfort and improves daily function

Additional Uses

In some cases, Hydroxychloroquine may also be prescribed for:

Off-label uses as determined by your healthcare provider
Combination therapy with other medications
Long-term management of chronic conditions
Short-term treatment of acute symptoms

Dosage and Administration

Hydroxychloroquine dosing varies based on the specific condition being treated and individual patient factors.

Typical Dosing:

Starting dose is typically determined by your healthcare provider
May be adjusted based on response and tolerability
Can be taken with or without food (follow specific instructions)
Usually taken once or twice daily

Administration Tips:

Take at the same time(s) each day for best results
Swallow tablets/capsules whole unless instructed otherwise
Don't skip doses
Complete full course of treatment as prescribed
Follow your doctor's specific instructions carefully

Important Safety Information

Who Should Not Take Hydroxychloroquine?

Do not take Hydroxychloroquine if you:

Are allergic to Hydroxychloroquine or any ingredients
Have certain medical conditions (discuss with your doctor)
Are taking medications that interact with Hydroxychloroquine
Have severe liver or kidney disease (without dose adjustment)

Drug Interactions

Inform your doctor about all medications you take, including:

Prescription medications
Over-the-counter drugs
Vitamins and supplements
Herbal products

Some medications may interact with Hydroxychloroquine, affecting its efficacy or increasing side effect risk.

Pregnancy and Breastfeeding

Pregnancy:

Discuss risks and benefits with your doctor if pregnant or planning pregnancy
May require special monitoring or dose adjustments
Some medications should be avoided during pregnancy

Breastfeeding:

Consult your doctor about safety while breastfeeding
May pass into breast milk
Benefits and risks should be carefully considered

Monitoring and Follow-Up

While taking Hydroxychloroquine, your doctor may monitor:

Effectiveness of treatment (symptom improvement)
Side effects or adverse reactions
Laboratory values if applicable
Blood pressure, heart rate, or other vital signs as appropriate
Overall response to therapy

Regular follow-up appointments are important to ensure the medication is working properly and to make any necessary adjustments.

Managing Side Effects

Most side effects are mild and improve with time. Here are strategies for common side effects:

Gastrointestinal Upset

Take with food if allowed
Stay well hydrated
Eat smaller, more frequent meals
Report persistent nausea or vomiting

Dizziness

Rise slowly from sitting or lying positions
Avoid sudden movements
Stay hydrated
Avoid alcohol
Report severe or persistent dizziness

Fatigue

Get adequate rest
Maintain regular sleep schedule
Exercise as tolerated
Report excessive tiredness that interferes with daily activities

Lifestyle Considerations

To maximize the benefits of Hydroxychloroquine:

Follow a healthy, balanced diet
Exercise regularly as recommended by your doctor
Maintain a healthy weight
Avoid alcohol or limit consumption
Don't smoke
Manage stress through relaxation techniques
Get adequate sleep
Stay well hydrated
Keep all follow-up appointments
Take medication consistently as prescribed

When to Contact Your Doctor

Seek immediate medical attention if you experience:

Signs of severe allergic reaction (difficulty breathing, severe rash, swelling)
Chest pain or rapid heartbeat
Severe dizziness or fainting
Unusual bleeding or bruising
Signs of liver problems (yellowing of skin/eyes, dark urine, severe fatigue)
Severe stomach pain
Any symptoms that concern you

Contact your doctor for non-emergency issues:

Mild to moderate side effects that persist
Questions about your medication
Concerns about effectiveness
New medications prescribed by another doctor
Scheduled surgery or dental procedures
Planning pregnancy

Storage

Store Hydroxychloroquine at room temperature (68-77°F or 20-25°C) away from light, heat, and moisture. Keep in original container. Keep out of reach of children and pets. Do not use past expiration date.

Important Reminders

Take exactly as prescribed by your doctor
Don't stop suddenly without medical advice
Keep all follow-up appointments
Report any unusual symptoms
Don't share medication with others
Store safely away from children
Check expiration dates
Ask your pharmacist if you have questions

Clinical Benefits

When used appropriately, Hydroxychloroquine provides several benefits:

Effective management of lupus, rheumatoid arthritis, and malaria
Improvement in quality of life
Reduction in symptoms
Prevention of complications
Generally well-tolerated when used as directed
Backed by clinical research and extensive use

Disclaimer: This information is for educational purposes only and is not intended to replace professional medical advice, diagnosis, or treatment. Always consult your physician or other qualified healthcare provider with any questions about a medical condition or medication.

Frequently Asked Questions

Symptomatic improvement is typically gradual and may take 8 to 12 weeks to become noticeable, with maximum benefit at 4 to 6 months. Hydroxychloroquine is not a quick-acting medication — it works by modulating the immune system over time. Continuing therapy consistently, even during apparent remission, helps prevent flares.

Long-term hydroxychloroquine can cause irreversible retinal toxicity (bull's-eye maculopathy), particularly after five or more years of use. The American Academy of Ophthalmology recommends a baseline retinal exam within the first year of starting therapy, then annual screening with optical coherence tomography (OCT) and visual field testing beginning at 5 years of use, or earlier in higher-risk patients.

Yes. Taking hydroxychloroquine with a meal or a glass of milk significantly reduces nausea, abdominal cramping, and diarrhea — the most common side effects. Splitting the daily dose into morning and evening administrations also improves tolerability.

Yes. For women with lupus or other autoimmune conditions, current rheumatology and obstetric guidelines recommend continuing hydroxychloroquine throughout pregnancy and breastfeeding. Stopping the medication often precipitates disease flares, which carry greater risks to both mother and baby than the medication itself.

No. Despite early speculation, well-designed randomized trials demonstrated no clinical benefit of hydroxychloroquine in preventing or treating COVID-19, and major guidelines recommend against its use for this indication. Its proven roles remain in autoimmune disease and select malaria regimens.

Questions to Ask Your Doctor

Consider discussing these topics at your next appointment:

✓When should I have my baseline and follow-up retinal eye exams?
✓How will we know if hydroxychloroquine is working for my condition?
✓Is my dose appropriate for my weight to minimize the risk of eye toxicity?
✓Which of my other medications could interact with hydroxychloroquine, and do any need monitoring?
✓What side effects should make me call you between visits?

Schedule an Appointment

Related Health Conditions

This medication is commonly used to treat or manage the following conditions:

Attention Deficit Hyperactivity Disorder (ADHD)

ADHD is a neurodevelopmental disorder marked by inattention, hyperactivity, and/or impulsivity, stemming from complex interactions between genetics, brain differences, and environmental factors, not poor parenting.

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Lupus Anticoagulant

Lupus anticoagulant is an antibody causing paradoxical prolonged clotting tests yet increasing thrombosis risk, linked to antiphospholipid syndrome and autoimmune diseases, despite not always requiring lupus diagnosis.

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Vertigo

Vertigo, a spinning sensation distinct from dizziness, often stems from inner ear or brain issues like BPPV or Meniere's, sometimes triggered by head trauma or medication.

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Medical Disclaimer: This information is for educational purposes only and should not be considered medical advice. Always consult with your healthcare provider before starting, stopping, or changing any medication. Your doctor can provide personalized recommendations based on your specific health condition and medical history.