Hydroxychloroquine is an antimalarial and immunomodulatory agent widely prescribed for its efficacy in managing chronic autoimmune diseases. It functions by modulating immune system activity, thereby reducing inflammation and disease progression. Clinically, it is a cornerstone therapy for conditions like systemic lupus erythematosus and rheumatoid arthritis, offering patients sustained symptom control and improved quality of life. Its well-established safety profile and oral administration make it a practical long-term treatment option under medical supervision.

Features

• Active ingredient: Hydroxychloroquine sulfate
• Available in 200 mg and 400 mg oral tablets
• FDA-approved for malaria prophylaxis and treatment of autoimmune disorders
• Mechanism: Interferes with antigen processing and reduces cytokine production
• Prescription-only medication requiring diagnostic confirmation
• Generic and brand-name formulations (e.g., Plaquenil®)

Benefits

• Reduces disease activity and flare frequency in autoimmune conditions
• Helps preserve joint function and prevent structural damage in rheumatoid arthritis
• Decreases skin manifestations and systemic involvement in lupus erythematosus
• May lower cardiovascular risk in chronic inflammatory diseases
• Generally well-tolerated with a predictable side effect profile when monitored
• Allows for reduced corticosteroid dependence over time

Common use

Hydroxychloroquine is primarily indicated for the treatment of uncomplicated malaria, malaria prophylaxis, and autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus. It is also used off-label for other inflammatory conditions including Sjögren’s syndrome, cutaneous lupus, and porphyria cutanea tarda. Treatment is typically long-term, requiring regular monitoring to assess therapeutic response and screen for adverse effects.

Dosage and direction

Dosage must be individualized based on indication, patient weight, renal function, and clinical response. For autoimmune diseases, the typical adult dose is 200–400 mg daily, often starting at a lower dose to assess tolerance. Doses exceeding 5 mg/kg actual body weight per day are generally avoided to minimize retinal toxicity risk. Tablets should be taken with food or milk to reduce gastrointestinal upset. Regular ophthalmologic screening is recommended due to potential retinopathy risk.

Precautions

Patients should undergo a baseline ophthalmologic examination and periodic evaluations (e.g., annually after 5 years of use). Renal and hepatic function should be assessed before and during treatment. Use with caution in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency due to hemolysis risk. May exacerbate psoriasis or precipitate porphyria. Not recommended during pregnancy unless potential benefit justifies potential risk; use during lactation should be carefully considered.

Contraindications

Hypersensitivity to hydroxychloroquine, 4-aminoquinoline compounds, or any component of the formulation. Contraindicated in patients with pre-existing retinal field changes attributable to 4-aminoquinolines. Avoid use in patients with known porphyria. Not recommended in those with severe hepatic or renal impairment without close monitoring.

Possible side effect

Common side effects include nausea, abdominal cramps, diarrhea, headache, and dizziness. Skin reactions such as rash or pruritus may occur. Rare but serious adverse effects include irreversible retinopathy, cardiomyopathy, QT prolongation, and hematologic abnormalities like agranulocytosis or aplastic anemia. Neuropsychiatric events such as anxiety, mood changes, or nightmares have been reported.

Drug interaction

Hydroxychloroquine may interact with drugs that prolong QT interval (e.g., antiarrhythmics, macrolides). Concomitant use with other hepatotoxic agents may increase liver injury risk. May enhance the effects of insulin and oral hypoglycemics. Antacids and kaolin may reduce absorption. May decrease levels of anticonvulsants such as phenytoin. Use with digoxin may increase digoxin serum concentrations.

Missed dose

If a dose is missed, it should be taken as soon as remembered unless it is nearly time for the next dose. Do not double the dose to make up for a missed one. Consistent daily administration is important to maintain therapeutic levels, particularly in chronic autoimmune disease management.

Overdose

Overdose can be fatal and may present with headache, drowsiness, visual disturbances, cardiovascular collapse, seizures, and hypokalemia. Immediate medical attention is required. Treatment is supportive and may include gastric lavage, activated charcoal, and respiratory and cardiac monitoring. There is no specific antidote.

Storage

Store at room temperature (20–25°C/68–77°F) in a tightly closed container, protected from light and moisture. Keep out of reach of children and pets. Do not use beyond the expiration date printed on the packaging.

Disclaimer

This information is for educational purposes and does not replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before starting or changing any medication regimen. Individual patient needs and responses may vary.

Reviews

Hydroxychloroquine is generally regarded by rheumatologists and dermatologists as a foundational therapy in autoimmune disease management. Clinical studies and long-term use support its efficacy in reducing disease activity and steroid use. However, retinal toxicity remains a significant concern requiring vigilant monitoring. Patient-reported outcomes often highlight improved daily functioning and reduced symptom burden, though gastrointestinal side effects can affect adherence in some cases.