What is Hydroxychloroquine: Uses, Dosage, Side Effects and More

Hydroxychloroquine is a prescription medication that doctors use to treat malaria, rheumatoid arthritis, and lupus. You might know it better by its brand name, Plaquenil, and it belongs to a group of medicines called antimalarials that work by reducing inflammation in your body.

This medication has been safely used for decades to help people manage chronic autoimmune conditions. While it made headlines during the COVID-19 pandemic, its primary role remains helping people with arthritis and lupus live more comfortable lives.

What is Hydroxychloroquine?

Hydroxychloroquine is a synthetic antimalarial drug that also acts as an immunosuppressant. It's a modified version of chloroquine, designed to be gentler on your body while still providing effective treatment for certain conditions.

The medication works by interfering with the communication between certain cells in your immune system. Think of it as turning down the volume on an overactive immune response that causes inflammation and pain in conditions like rheumatoid arthritis and lupus.

Doctors consider hydroxychloroquine a disease-modifying antirheumatic drug, or DMARD for short. This means it doesn't just treat symptoms but can actually slow down the progression of autoimmune diseases over time.

What is Hydroxychloroquine Used For?

Hydroxychloroquine treats three main conditions: malaria prevention and treatment, rheumatoid arthritis, and systemic lupus erythematosus. Your doctor prescribes it based on your specific condition and medical history.

For malaria, this medication both prevents infection when you're traveling to areas where malaria is common and treats active infections. It works by interfering with the malaria parasite's ability to survive in your red blood cells.

In rheumatoid arthritis, hydroxychloroquine helps reduce joint pain, swelling, and morning stiffness. Many people notice their symptoms improve gradually over several months of treatment, and it can help prevent joint damage from getting worse.

For lupus patients, this medication helps control skin rashes, joint pain, and fatigue. It's particularly effective at preventing lupus flares and can reduce the need for stronger medications like steroids.

Sometimes doctors prescribe hydroxychloroquine for other autoimmune conditions like Sjögren's syndrome or certain skin conditions. These are considered "off-label" uses, meaning the medication wasn't specifically approved for these conditions but has shown benefits in medical studies.

How Does Hydroxychloroquine Work?

Hydroxychloroquine is considered a moderate-strength medication that works gradually over time. Unlike pain relievers that work within hours, this medication builds up in your system and may take several weeks or months to show its full effects.

The drug works by entering certain cells in your immune system and changing how they function. It reduces the production of inflammatory chemicals that cause pain, swelling, and tissue damage in autoimmune diseases.

For malaria, hydroxychloroquine interferes with the parasite's ability to digest hemoglobin in your red blood cells. This essentially starves the parasite and prevents it from multiplying and causing illness.

The medication also has mild effects on your skin's sensitivity to sunlight and can help reduce certain types of skin rashes. This is why it's sometimes prescribed for skin conditions related to lupus or other autoimmune diseases.

How Should I Take Hydroxychloroquine?

Take hydroxychloroquine exactly as your doctor prescribes, typically once or twice daily with food or milk. Taking it with food helps reduce stomach upset, which is one of the most common side effects.

Swallow the tablets whole with a full glass of water. Don't crush, chew, or break the tablets, as this can affect how the medication is absorbed and may increase side effects.

If you're taking it for malaria prevention, start the medication one to two weeks before traveling to a malaria-endemic area. Continue taking it weekly while you're there and for four weeks after you return home.

For rheumatoid arthritis or lupus, you'll likely take it daily. It's helpful to take it at the same time each day to maintain steady levels in your system and help you remember your doses.

Avoid taking hydroxychloroquine with antacids containing aluminum, magnesium, or calcium, as these can interfere with absorption. If you need an antacid, take it at least four hours before or after your hydroxychloroquine dose.

How Long Should I Take Hydroxychloroquine For?

The length of treatment depends entirely on your condition and how well you respond to the medication. For malaria prevention, you'll take it for the duration of your travel plus four weeks after returning home.

For rheumatoid arthritis and lupus, hydroxychloroquine is typically a long-term treatment. Many people take it for years to help control their symptoms and prevent disease progression.

Your doctor will monitor your response to the medication and may adjust your treatment plan over time. Some people notice improvement within a few weeks, while others may need three to six months to experience the full benefits.

Never stop taking hydroxychloroquine suddenly without talking to your doctor first. For autoimmune conditions, stopping abruptly can lead to a flare-up of symptoms that might be worse than before you started treatment.

Your doctor will schedule regular check-ups to monitor your progress and watch for any side effects. These visits are important for ensuring the medication continues to be safe and effective for you.

What Are the Side Effects of Hydroxychloroquine?

Most people tolerate hydroxychloroquine well, but like all medications, it can cause side effects. The good news is that serious side effects are relatively uncommon, especially when the medication is used properly and monitored regularly.

Let's start with the most common side effects you might experience, which are usually mild and often improve as your body adjusts to the medication.

Common side effects include:

• Stomach upset, nausea, or mild abdominal pain
• Diarrhea or loose stools
• Headache
• Dizziness or lightheadedness
• Skin rash or itching
• Loss of appetite

These symptoms often lessen within a few weeks as your body gets used to the medication. Taking hydroxychloroquine with food can help reduce stomach-related side effects significantly.

Now, let's discuss some less common but more serious side effects that require medical attention. While these occur in a small percentage of people, it's important to be aware of them.

Less common but serious side effects include:

• Vision changes, including blurred vision or difficulty seeing
• Hearing problems or ringing in the ears
• Muscle weakness or coordination problems
• Mood changes, including depression or anxiety
• Unusual bruising or bleeding
• Severe skin reactions

Vision problems deserve special attention because they can be permanent if not caught early. Your doctor will recommend regular eye exams to monitor for retinal changes, which can occur with long-term use.

There are also some rare but serious side effects that require immediate medical attention. These are uncommon, but knowing about them can help you seek help quickly if needed.

Rare but serious side effects include:

• Severe heart rhythm problems
• Severe allergic reactions with difficulty breathing
• Seizures or convulsions
• Severe muscle damage (rhabdomyolysis)
• Blood disorders affecting white blood cells or platelets
• Severe liver problems

If you experience any of these serious side effects, contact your doctor immediately or seek emergency medical care. Remember, these complications are rare, but early recognition and treatment are important for your safety.

Who Should Not Take Hydroxychloroquine?

Certain people should avoid hydroxychloroquine or use it only under very careful medical supervision. Your doctor will review your medical history thoroughly before prescribing this medication.

You should not take hydroxychloroquine if you're allergic to it, chloroquine, or any of its ingredients. Previous allergic reactions to antimalarial medications are a clear reason to avoid this drug.

People with certain eye conditions, particularly retinal or visual field changes, should generally avoid hydroxychloroquine. The medication can worsen existing eye problems and make vision changes permanent.

If you have severe heart rhythm problems, especially a condition called QT prolongation, hydroxychloroquine may not be safe for you. The medication can affect your heart's electrical system and worsen existing rhythm disorders.

Certain other conditions require extra caution and close monitoring. Your doctor will weigh the benefits against the risks if you have any of these conditions.

Conditions requiring special caution include:

• Kidney disease or reduced kidney function
• Liver disease or liver function problems
• Blood disorders like anemia or low white blood cell count
• Glucose-6-phosphate dehydrogenase (G6PD) deficiency
• Psoriasis or porphyria
• Hearing problems or ear disorders

Pregnancy and breastfeeding also require special consideration. While hydroxychloroquine is generally considered safer than many other medications for autoimmune diseases during pregnancy, your doctor will carefully evaluate whether the benefits outweigh any potential risks.

Hydroxychloroquine Brand Names

Plaquenil is the most well-known brand name for hydroxychloroquine in the United States. This brand has been available for decades and is the version most doctors and patients are familiar with.

Generic versions of hydroxychloroquine are also widely available and contain the same active ingredient as Plaquenil. These generic versions are typically less expensive and work just as effectively as the brand-name medication.

Your pharmacy may substitute a generic version unless your doctor specifically writes "brand name only" on your prescription. Both generic and brand-name versions must meet the same safety and effectiveness standards set by the FDA.

If you're switching between different manufacturers of hydroxychloroquine, let your doctor know. While the medications should work the same way, some people are sensitive to differences in inactive ingredients or manufacturing processes.

Hydroxychloroquine Alternatives

Several alternative medications can treat the same conditions as hydroxychloroquine, though the best choice depends on your specific condition and medical history. Your doctor will help you find the most appropriate option if hydroxychloroquine isn't right for you.

For rheumatoid arthritis, other DMARDs like methotrexate, sulfasalazine, or leflunomide might be suitable alternatives. Biologic medications like adalimumab or etanercept are also options for people with more severe disease.

Lupus patients might benefit from other antimalarials like chloroquine, though this medication has more side effects than hydroxychloroquine. Immunosuppressive drugs like methotrexate or mycophenolate mofetil are also used for lupus treatment.

For malaria prevention, alternatives include doxycycline, mefloquine, or atovaquone-proguanil. The best choice depends on where you're traveling and your individual risk factors.

Your doctor will consider factors like your other medical conditions, medications you're taking, and how well you've responded to previous treatments when recommending alternatives.

Is Hydroxychloroquine Better Than Methotrexate?

Neither hydroxychloroquine nor methotrexate is universally "better" – they're different medications with distinct advantages and disadvantages. The best choice for you depends on your specific condition, severity of symptoms, and individual response to treatment.

Hydroxychloroquine is generally considered gentler with fewer serious side effects, making it a good first-line treatment for mild to moderate rheumatoid arthritis and lupus. It's particularly appealing because it doesn't suppress your immune system as much as methotrexate.

Methotrexate is typically more effective for severe rheumatoid arthritis and is often considered the gold standard DMARD. However, it requires more frequent monitoring and has more potential side effects, including liver problems and increased infection risk.

Many doctors start with hydroxychloroquine for newly diagnosed patients, especially those with milder symptoms. If hydroxychloroquine doesn't provide enough relief after several months, they might switch to or add methotrexate.

Some people take both medications together, as they can work synergistically to provide better symptom control than either medication alone. Your doctor will help determine the best approach based on your individual situation.