From the Guidelines
Hydroxychloroquine should not be used to treat COVID-19 due to the lack of evidence supporting its effectiveness and the increased risk of adverse events, including cardiac toxicity and retinopathy, as demonstrated in large randomized controlled studies such as the UK RECOVERY group and World Health Organization (WHO) SOLIDARITY trial 1.
Introduction to Hydroxychloroquine
Hydroxychloroquine is an FDA-approved medication primarily used to treat malaria, lupus, and rheumatoid arthritis.
Typical Dosage and Usage
The typical dosage for adults with rheumatoid arthritis is 400-600 mg daily for 4-12 weeks, then reduced to a maintenance dose of 200-400 mg daily. For lupus, the usual dose is 200-400 mg daily. When used 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.
Side Effects and Precautions
Common side effects include nausea, headache, dizziness, and diarrhea. Long-term use requires regular eye exams due to the risk of retinal damage, with studies suggesting that a daily dose of ≤5.0 mg/kg real weight minimizes this risk 2.
COVID-19 Treatment
Despite controversy during the COVID-19 pandemic, clinical trials did not support its effectiveness for COVID-19 treatment, and it is not recommended for this purpose, as evidenced by the lack of survival benefit and increased risk of adverse events in studies such as the RECOVERY trial and WHO SOLIDARITY trial 1.
Patient Guidance
Patients should take hydroxychloroquine with food to reduce stomach upset and follow their healthcare provider's instructions carefully, ensuring they are aware of the potential risks and benefits associated with its use, particularly in the context of COVID-19 treatment where alternative, evidence-supported therapies should be prioritized.
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 malaria, as well as the treatment of rheumatoid arthritis, systemic lupus erythematosus, and chronic discoid lupus erythematosus in adults 3.
- Malaria: treatment of uncomplicated malaria and prophylaxis in areas where chloroquine resistance is not reported
- Rheumatoid arthritis: treatment in adults
- Systemic lupus erythematosus: treatment in adults
- Chronic discoid lupus erythematosus: treatment in adults
From the Research
Uses of Hydroxychloroquine (HCQ)
- HCQ is used as an antimalarial agent [(4, 5, 6, 7, 8)]
- It is also used as an immunomodulatory and anti-inflammatory agent for the management of autoimmune and rheumatic diseases such as: + Systemic lupus erythematosus [(4, 5, 6)] + Rheumatoid arthritis [(4, 5, 6)] + Antiphospholipid syndrome 6 + Primary Sjögren's syndrome 6
- HCQ has been investigated as a potential treatment for COVID-19, although its efficacy and safety for this use are still uncertain [(4, 5, 7, 8)]
Mechanisms of Action
- HCQ inhibits lysosomal antigen processing, MHC-II antigen presentation, and TLR functions 4
- It also has anti-inflammatory, antioxidant, and antiviral mechanisms 5
Adverse Effects
- Common adverse effects include gastrointestinal symptoms such as nausea, vomiting, and diarrhea 8
- Less common adverse effects include: + Glucose abnormalities 8 + Cardiotoxicity, including conduction abnormalities and QT/QTc prolongation 8 + Dermatologic reactions, such as drug eruptions or rashes 8 + Neuropsychiatric symptoms, such as confusion, disorientation, and hallucination 8
- Long-term use of HCQ can lead to retinopathy, cardiotoxicity, and neuromyotoxicity 8