Plaquenil (hydroxychloroquine sulfate) is a disease-modifying antirheumatic drug (DMARD) widely prescribed for the management of chronic autoimmune disorders. As an immunomodulatory agent, it works by altering immune system activity to reduce inflammation and prevent disease progression. It is indicated for conditions such as rheumatoid arthritis, systemic lupus erythematosus, and malaria prophylaxis. With a well-established safety profile and oral administration, Plaquenil remains a cornerstone therapy in rheumatology and dermatology.

Features

• Contains hydroxychloroquine sulfate as the active ingredient
• Available in 200 mg film-coated tablets
• Oral administration with once or twice daily dosing
• Long half-life allowing for steady-state plasma concentrations
• FDA-approved for autoimmune and parasitic indications

Benefits

• Reduces joint pain, swelling, and stiffness in rheumatoid arthritis
• Decreases frequency and severity of lupus flares
• Helps prevent long-term joint damage and disability
• May improve skin manifestations in cutaneous lupus
• Provides chemoprophylaxis against malaria in endemic areas
• Offers convenient oral dosing compared to biologic therapies

Common use

Plaquenil is primarily prescribed for the management of autoimmune conditions including rheumatoid arthritis, systemic lupus erythematosus, and discoid lupus erythematosus. It is also used for malaria prophylaxis in travelers to endemic regions and occasionally employed off-label for other autoimmune conditions such as Sjögren’s syndrome and porphyria cutanea tarda. The medication is typically used as part of a comprehensive treatment plan that may include other DMARDs, NSAIDs, or corticosteroids.

Dosage and direction

The recommended dosage for rheumatoid arthritis is 400-600 mg daily initially, followed by a maintenance dose of 200-400 mg daily. For lupus erythematosus, doses typically range from 200-400 mg daily. Malaria prophylaxis requires 400 mg once weekly starting two weeks before exposure and continuing for four weeks after leaving the endemic area. Tablets should be taken with food or milk to minimize gastrointestinal upset. Regular ophthalmologic examinations are recommended due to potential retinal toxicity.

Precautions

Patients should undergo baseline and annual ophthalmologic examinations including visual field testing and spectral domain OCT. Renal and hepatic function should be monitored periodically. Blood glucose levels may be affected in diabetic patients. Caution is advised in patients with psoriasis, as hydroxychloroquine may exacerbate the condition. Patients should be advised that therapeutic effects may not be apparent for several weeks to months.

Contraindications

Plaquenil is contraindicated in patients with known hypersensitivity to hydroxychloroquine or 4-aminoquinoline compounds. It should not be used in patients with pre-existing retinal field changes attributable to 4-aminoquinoline compounds. Contraindications also include concurrent use with other drugs known to cause retinal toxicity or hearing impairment.

Possible side effects

Common side effects include gastrointestinal disturbances (nausea, vomiting, diarrhea), headache, dizziness, and skin eruptions. More serious adverse effects may include retinal toxicity, cardiomyopathy, skeletal muscle myopathy, and blood dyscrasias. Psychiatric reactions such as anxiety, depression, and hallucinations have been reported rarely. Any visual changes should be reported immediately to a healthcare provider.

Drug interaction

Plaquenil may enhance the effects of digoxin and insulin. Concomitant use with hepatotoxic drugs may increase the risk of liver damage. Antacids and kaolin may reduce absorption. It may potentiate the effects of other QT-prolonging agents. Combination with other myelosuppressive drugs may increase the risk of blood dyscrasias.

Missed dose

If a dose is missed, it should be taken as soon as remembered unless it is almost time for the next dose. Patients should not double the dose to make up for a missed one. For weekly malaria prophylaxis, if a dose is missed, instruct the patient to take it as soon as possible and then resume the regular weekly schedule.

Overdose

Overdose may cause cardiovascular collapse, seizures, and respiratory arrest. Symptoms may include headache, visual disturbances, drowsiness, and hypokalemia. Management involves immediate gastric lavage and symptomatic treatment. Cardiorespiratory support and ECG monitoring are essential. Dialysis is not effective due to extensive tissue binding.

Storage

Store at room temperature (15-30°C or 59-86°F) in a tight, light-resistant container. Keep out of reach of children. Do not use after the expiration date printed on the packaging. Protect from moisture and excessive heat.

Disclaimer

This information is for educational purposes only and does not constitute medical advice. Always consult with a qualified healthcare professional before starting or changing any treatment regimen. Individual response to medication may vary, and proper medical supervision is essential throughout treatment.

Reviews

Clinical studies demonstrate Plaquenil’s efficacy in reducing disease activity scores in rheumatoid arthritis by 50-70% and decreasing lupus flare frequency by approximately 50%. Long-term observational studies show sustained benefits over years of treatment with appropriate monitoring. Patient-reported outcomes indicate improvements in quality of life measures and functional capacity. Ophthalmologic monitoring has reduced the incidence of serious retinal toxicity to less than 1% with proper dosing and surveillance.