What are the guidelines for using Hydroxychloroquine (Plaquenil) for treating malaria, autoimmune diseases, and COVID-19?

From the Guidelines

Hydroxychloroquine is not recommended for the treatment of COVID-19 due to the lack of demonstrated benefit and potential cardiac side effects. For malaria prevention, adults typically take 400 mg once weekly, starting 1-2 weeks before travel and continuing for 4 weeks after leaving the endemic area 1. For malaria treatment, 800 mg initially, followed by 400 mg at 6,24, and 48 hours is standard. For autoimmune conditions like rheumatoid arthritis and lupus, the usual dose is 200-400 mg daily, with maintenance doses often reduced to the lowest effective amount (typically 200 mg daily) 1. Regular eye examinations are essential as hydroxychloroquine can cause retinal damage with long-term use, particularly at higher doses or with kidney dysfunction.

Key Considerations

• Hydroxychloroquine requires careful monitoring, especially for cardiac complications (QT prolongation), and should be used with caution in patients with heart conditions, G6PD deficiency, or liver/kidney disease 1.
• Common side effects include nausea, headache, and skin rashes.
• The medication works by reducing inflammation and modulating immune responses in autoimmune conditions, while for malaria it interferes with the parasite's ability to detoxify heme, a byproduct of hemoglobin digestion.
• Large randomized controlled studies have shown no benefit of hydroxychloroquine in the treatment of COVID-19, with a pooled estimate for mortality of 1.08 (95% CI 0.97–1.19) 1.

Important Warnings

• Hydroxychloroquine can cause cardiac toxicity, including QT prolongation, and should be used with caution in patients with heart conditions 1.
• The medication can also cause liver toxicity and should be used with caution in patients with liver disease 1.
• Regular monitoring of liver function and cardiac function is essential when using hydroxychloroquine.

Summary of Recommendations

• Do not use hydroxychloroquine for the treatment of COVID-19 due to the lack of demonstrated benefit and potential cardiac side effects 1.
• Use hydroxychloroquine with caution in patients with heart conditions, G6PD deficiency, or liver/kidney disease.
• Monitor patients regularly for cardiac and liver toxicity when using hydroxychloroquine.

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 guidelines for using Hydroxychloroquine (Plaquenil) are as follows:

• Malaria treatment: Hydroxychloroquine is indicated for the treatment of uncomplicated malaria due to Plasmodium falciparum, Plasmodium malariae, Plasmodium ovale, and Plasmodium vivax in adult and pediatric patients.
• Malaria prophylaxis: Hydroxychloroquine is indicated for prophylaxis of malaria in geographic areas where chloroquine resistance is not reported in adult and pediatric patients.
• Autoimmune diseases: Hydroxychloroquine is indicated for the treatment of rheumatoid arthritis, systemic lupus erythematosus, and chronic discoid lupus erythematosus in adults.
• COVID-19: There is no information in the provided drug labels that supports the use of Hydroxychloroquine for treating COVID-19 2, 2.

From the Research

Guidelines for Using Hydroxychloroquine

• Hydroxychloroquine is an antimalarial drug that has been used to treat malaria, autoimmune diseases, and has been tested as a potential treatment for COVID-19 3, 4, 5.
• For malaria chemoprophylaxis, the recommended dose is not specified in the provided studies, but it is mentioned that the doses required for COVID-19 prophylaxis are higher than those recommended for malaria chemoprophylaxis 3.
• For autoimmune diseases such as systemic lupus erythematosus, rheumatoid arthritis, and Sjögren's syndrome, hydroxychloroquine is used as an immunomodulatory agent, and its efficacy is linked to inhibiting lysosomal antigen processing, MHC-II antigen presentation, and TLR functions 4, 6.
• For COVID-19, the efficacy of hydroxychloroquine remains uncertain, and its use should be discouraged outside clinical trials under strict medical supervision 4, 7.
• The recommended dose for COVID-19 prophylaxis is an 800 mg loading dose followed by 400 mg twice or 3 times weekly, or an 800 mg loading dose followed in 6 hours by 600 mg, then 600 mg daily for 4 more days 3.

Safety and Efficacy

• Hydroxychloroquine is generally well-tolerated, but severe life-threatening adverse effects, including cardiomyopathy and conduction defects, have been reported 4, 7.
• The use of hydroxychloroquine for COVID-19 has been associated with cardiac and other adverse events, and its use should be carefully considered and monitored 7.
• Clinical trials are needed to establish the safety and efficacy of hydroxychloroquine for COVID-19 prophylaxis and treatment 3, 7.

Prescribing Patterns

• Before 2020, primary care providers and specialists who routinely prescribed hydroxychloroquine, such as rheumatologists and dermatologists, accounted for approximately 97% of new prescriptions 7.
• New prescriptions by specialists who did not typically prescribe these medications increased significantly in March 2020, but dispensing trends are returning to pre-pandemic levels 7.
• Continued adherence to current clinical guidelines for the indicated use of hydroxychloroquine will ensure its availability and benefit to patients for whom its use is indicated 7.