What is the use of Hydroxychloroquine (HCQ)?

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Last updated: March 27, 2025View editorial policy

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From the Guidelines

Hydroxychloroquine should not be used to treat COVID-19 due to the lack of evidence showing its effectiveness and the potential for increased adverse events, including cardiac toxicity and retinopathy, as demonstrated in recent studies 1.

Overview of Hydroxychloroquine

Hydroxychloroquine is an antimalarial medication that is also used to treat autoimmune conditions like rheumatoid arthritis and systemic lupus erythematosus. The typical dosage for adults with rheumatoid arthritis is 400-600 mg daily for 4-12 weeks, then 200-400 mg daily for maintenance. For lupus, the usual dose is 200-400 mg daily. For malaria prevention, adults typically take 400 mg once weekly, starting 1-2 weeks before travel to endemic areas and continuing for 4 weeks after leaving.

Mechanism of Action and Side Effects

Hydroxychloroquine works by interfering with lysosomal activity and autophagy, reducing inflammation in autoimmune conditions, and disrupting parasite metabolism in malaria. Common side effects include nausea, headache, and dizziness. Long-term use requires regular eye exams as it can rarely cause retinopathy. The medication should be taken with food to reduce stomach upset, and patients should report any visual changes immediately.

Use in COVID-19

Despite controversy during the COVID-19 pandemic, hydroxychloroquine has not been proven effective for treating this virus. Large randomized controlled studies, such as the UK RECOVERY group and World Health Organization (WHO) SOLIDARITY trial, have shown no apparent effect of hydroxychloroquine on mortality, irrespective of disease severity at study entry 1. Furthermore, the use of hydroxychloroquine has been associated with an increased risk of adverse events, including cardiac toxicity and retinopathy 1.

Recommendations

  • Hydroxychloroquine should only be used for its approved indications under medical supervision.
  • Patients with rheumatoid arthritis or systemic lupus erythematosus should be monitored regularly for signs of retinopathy and other adverse events.
  • The dosage of hydroxychloroquine should be adjusted based on actual body weight to minimize the risk of toxicity, with a recommended dose of ≤5.0 mg/kg/day 1.
  • Patients should be advised to report any visual changes immediately and to take the medication with food to reduce stomach upset.

From the FDA Drug Label

Hydroxychloroquine sulfate tablets are an antimalarial and antirheumatic indicated for the: Treatment of uncomplicated malaria due to Plasmodium falciparum, Plasmodium malariae, Plasmodium ovale, and Plasmodium vivax in adult and pediatric patients. Prophylaxis of malaria in geographic areas where chloroquine resistance is not reported in adult and pediatric patients. Treatment of rheumatoid arthritis in adults. Treatment of systemic lupus erythematosus in adults. Treatment of chronic discoid lupus erythematosus in adults.

The use of Hydroxychloroquine (HCQ) is for the treatment and prophylaxis of certain conditions, including:

  • Malaria: treatment of uncomplicated malaria and prophylaxis in areas without chloroquine resistance
  • Rheumatoid arthritis: treatment in adults
  • Systemic lupus erythematosus: treatment in adults
  • Chronic discoid lupus erythematosus: treatment in adults 2 2

From the Research

Uses of Hydroxychloroquine (HCQ)

  • HCQ is commonly prescribed for the treatment of systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and other rheumatic diseases 3.
  • It has been used to treat conditions such as rheumatoid arthritis and systemic lupus erythematosus, and has also received attention as a possible treatment for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) 4.
  • HCQ has been used during the coronavirus disease 2019 (COVID-19) pandemic because of its reported anti-viral activity, although its effectiveness in treating COVID-19 is still being studied 5.
  • HCQ has proved to be effective in a number of autoimmune diseases including systemic lupus erythematosus (SLE), and may reduce the risk of flares, allow the reduction of the dosage of steroids, reduce organ damage, and prevent the thrombotic effects of anti-phospholipid antibodies 6.

Therapeutic Uses

  • HCQ is used to treat rheumatoid arthritis and systemic lupus erythematosus, and may be prescribed to pregnant women 6.
  • It has been used to prevent and treat malaria, and has also been used to treat other conditions such as dermatological disorders 4.
  • HCQ may offer several advantages not only in patients with mild SLE but can also exert important beneficial effects in lupus patients with organ involvement and in pregnant women 6.

Off-Label Uses

  • HCQ has been used off-label to treat COVID-19, although its effectiveness in treating this condition is still being studied 7, 5.
  • It has been used in clinical trials to study its potential as a prophylactic treatment for COVID-19 7.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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