Vaccine Info

Plaquenil Antiviral Medication

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Last reviewed
January 5, 2024

Plaquenil (Hydroxychloroquine) 2024

Plaquenil (Hydroxychloroquine) is U.S. FDA-approved to treat certain types of malaria and autoimmune conditions such as chronic discoid lupus erythematosus, systemic lupus erythematosus in adults, and rheumatoid arthritis, says the U.S. Centers for Disease Control and Prevention (CDC). The U.S. HHS Secretary Alex Azar clarified on June 15, 2020, that hydroxychloroquine remains FDA-authorized for various use cases. People with lupus should follow their doctor's guidance and the CDC's safety guidelines for people with compromised immune systems. Plaquenil (Hydroxychloroquine) is in a class of drugs called antimalarials. Hydroxychloroquine sulfate is a colorless crystalline solid, soluble in water to at least 20%; chemically, the drug is 2-[[4-[(7-Chloro-4-quinolyl)amino]pentyl]ethylamino] ethanol sulfate (1:1). Plaquenil (Hydroxychloroquine) is a more soluble and less toxic metabolite of chloroquine, which causes fewer side effects and is, therefore, assumed to be safer.

Plaquenil is a longer-acting medication that can take months to become effective. Conversely, the medicine can take weeks to "leave the body." Although hydroxychloroquine has a longer half-life -- around 40-45 days – than many medications, it is most effective and safe at its prescribed dosage. Therefore, it is essential to continue the prescribed dosage unless your prescribing doctor says otherwise, according to April 7, 2020, the U.S. Food and Drug Administration (FDA) approved an Abbreviated New Drug Application (ANDA) for Hydroxychloroquine (Plaquenil) Sulfate Tablets USP, 200 mg treatment uncomplicated malaria due to P. falciparum, P. malariae, P. ovale, and P. vivax. Chronic discoid lupus erythematosus and systemic lupus erythematosus in adults treat acute and chronic rheumatoid arthritis in adults. 

Hydroxychloroquine is registered in approximately 60 countries under different trade names: Plaquenil®, Quensyl®, and Plaquinol®, says Sanofi. Hydroxychloroquine was granted FDA approval in April 1955. Hydroxychloroquine's Accession Number is DB01611.

Plaquenil (Hydroxychloroquine) Indication

Studies indicate chloroquine prevents and treatment for malaria. Hydroxychloroquine is FDA-approved to prevent and treat certain types of malaria. It has a long elimination half-life of 30–45 days, allowing for weekly dosing when used to avoid malaria and a short 48-hour treatment course when used to treat malaria. Chloroquine is a lysosomotropic antimalarial drug that neutralizes lysosomal acidification, thus blocking autophagosomal degradation. Chloroquine use for influenza prevention has been researched for years and can effectively treat rheumatoid disease manifestations, such as joint pain and rashes, reduce thrombotic events, and prolong survival.

Plaquenil (Hydroxychloroquine) COVID-19

The World Health Organization (WHO) does not recommend hydroxychloroquine to prevent COVID-19. This recommendation is based on findings from six clinical trials with over 6,000 participants who did not have COVID-19 and received hydroxychloroquine.

A February 2024 study found HCQ use was associated with an 11% increase in the mortality rate in a meta-analysis of randomized trials. The number of hydroxychloroquine-related deaths in hospitalized patients is estimated at 16,990 in six countries. This study has some limitations, as some of the results should be taken cautiously, particularly those obtained in France, Turkey, and Belgium.

A study published in August 2023 concluded: The present report unveils the ultrastructural proof to complement the paradox regarding the role of prophylactic HCQ in COVID-19 patients. This study highlighted the level of SARS-CoV-2 infection and ultrastructural alteration in the preventive HCQ+ group in comparison to the HCQ group of the ciliated epithelium, type II pneumocytes, alveolar macrophage, neutrophil, and anucleated granulocytes individually. We found the significant antiviral activity of HCQ to have a protective role rather than a degenerating effect on the ciliated epithelium and type II pneumocytes in which low infection levels and relatively intact cellular ultrastructure were observed. The ultrastructure of alveolar macrophages and neutrophils was degenerated in ARDS patients of both the HCQ+ and HCQ− groups. However, enucleated fragments of granulocytes showed a higher tendency of phagocytosis of the mature SARS-COV-2 virus in the HCQ+ group.

A study published by New Microbes and New Infections on October 7, 2023, concluded that treating COVID-19 using a combination of hydroxychloroquine plus azithromycin was safe and was associated with a statistically significant mortality benefit in hospitalized patients - the OR for mortality in the treatment group was 0.635 vs. controls. These researchers analyzed raw data collected from a cohort of 30,423 patients with COVID-19 cared for at IHU Méditerranée Infection in Marseille, France, and extracted from the DRYAD open data platform and performed univariate and multivariable logistic regressions with all-cause mortality within six weeks. Multivariable logistic regressions were adjusted for sex, age group, variants, and type of patient management.

The RECOVERY and SOLIDARITY clinical studies did not demonstrate any benefit of treating COVID-19 with hydroxychloroquine. Both suffer from significant methodological problems, as the HCQ doses during the first 24 ​h (2400 ​mg) were four times higher than the highest recommended dose of 600 ​mg. 

Mayo Clinic's hydroxychloroquine webpage was removed in September 2023. However, that page was republished on September 26, 2023.

Plaquenil (Hydroxychloroquine) Side Effects

Side effects of Plaquenil (hydroxychloroquine) include irreversible retinal damage, cardiac effects (including cardiomyopathy and QT prolongation), worsening of psoriasis and porphyria, proximal myopathy, and neuropathy, neuropsychiatric events, and hypoglycemia. The FDA has published a Frequently Asked Questions document and added clinical trials studying HCQ.

Plaquenil (Hydroxychloroquine) Ingredients

PLAQUENIL (hydroxychloroquine sulfate) tablets contain 200 mg hydroxychloroquine sulfate, equivalent to 155 mg basre for oral administration. Inactive Ingredients: Dibasic calcium phosphate USP, hypromellose USP, magnesium stearate NF, polyethylene glycol 400 NF, polysorbate 80 NF, corn starch, titanium dioxide USP, carnauba wax NF, shellac NF, black iron oxide NF.

Plaquenil (Hydroxychloroquine) News

August 17, 2022 - UCLA Health published: Lupus is an autoimmune disease with several forms.

March 3, 2022 - The WHO reconfirmed its recommendation not to use hydroxychloroquine or chloroquine for COVID-19 treatment.

October 20, 2021 - The European Review published a new study: Safety profile of chloroquine and hydroxychloroquine: a disproportionality analysis of the FDA Adverse Event Reporting System database. Conclusions: Our results confirm previously published evidence and suggest that HCQ has a safer clinical profile than CQ and, thus, could serve as the drug of choice for future therapeutic purposes.

September 24, 2020 - A study found HCQ administration is safe for short-term treatment for patients with COVID-19 infection regardless of the clinical setting of delivery, causing only modest QTc prolongation and no directly attributable arrhythmic deaths.

August 3, 2020 - The Henry Ford Health System issued an open letter about its study, saying, "the political climate that has persisted has made any objective discussion about this drug impossible." The health system said in the letter that it would no longer comment.

July 9, 2020 - A study published in The Lancet stated: Recent randomized clinical trials have confirmed that hydroxychloroquine does not reduce mortality of hospitalized patients with severe cases of COVID-19 disease. And the risk of heart-related events is associated.

June 15, 2020 - The US FDA has concluded that it is no longer reasonable to believe that HCQ and CQ oral formulations may effectively treat COVID-19 disease patients in a hospital setting. Accordingly, the FDA revoked the EUA for emergency use of HCQ and CQ to treat COVID-19.

June 9, 2020 -  Study: Hydroxychloroquine inhibits trained immunity - implications for COVID-19 

June 3, 2020 - The World Health Organization (WHO) leader announced it would resume testing an experimental COVID-19 disease treatment, Plaquenil (Hydroxychloroquine).

May 27, 2020 - European Countries Ban Hydroxychloroquine Treatments for COVID-19 Patients.

May 22, 2020 - The Indian Council of Medical Research, India's apex body in the field, has found that consuming hydroxychloroquine reduces the chances of getting infected with COVID-19.

May 22, 2020 - A study published by The Lancet was retracted because the study authors could not assure the integrity of this observational study's data.

May 20, 2020 - Brazil's Health Ministry issued new guidelines for further use of antimalarial drug hydroxychloroquine in mild coronavirus cases.

On May 14, 2020, the U.S. FDA issued an ANDA for Hydroxychloroquine Sulfate Tablets USP, 200 mg, for the treatment of uncomplicated malaria due to P. falciparum, P. malariae, P. ovale, and P. vivax; chronic discoid lupus erythematosus and systemic lupus erythematosus in adults; and acute and chronic rheumatoid arthritis in adults. The full name of this applicant holder is HAVIX GROUP INC DBA.

May 5, 2020 - Early treatment of COVID-19 patients with hydroxychloroquine and azithromycin: A retrospective analysis of 1061 cases in Marseille, France.

April 17, 2020 - The Indian Council of Medical Research, under the Ministry of Health and Family Welfare, has recommended chemoprophylaxis with hydroxychloroquine (400 mg twice on day 1, then 400 mg once a week thereafter) for asymptomatic healthcare workers treating patients with suspected or confirmed COVID-19 and for asymptomatic household contacts of confirmed cases.

April 11, 2020 - A new study was performed by researchers at IHU Méditerranée Infection, Marseille, France, of the 1,061 coronavirus-infected patients treated entirely with hydroxychloroquine and azithromycin, mortality is around 0.5%, and that the cure rate is extremely high. It avoids worsening and clears virus persistence and contagiously in most cases.

April 9, 2020 - The Outcomes Related to COVID-19 treated with hydroxychloroquine among In-patients with symptomatic Disease study, or ORCHID Study, is being conducted by the Prevention and Early Treatment of Acute Lung Injury (PETAL) Clinical Trials Network of the National Heart, Lung, and Blood Institute (NHLBI), part of the National Institutes of Health.

April 8, 2020 - The ORCHID trial (Outcomes Related to COVID-19 treated with Hydroxychloroquine among In-patients with symptomatic Disease), funded by the National Heart, Lung and Blood Institute of the National Institutes of Health, enrolled its first patient on April 2 and will include hundreds of patients to determine if hydroxychloroquine is an effective treatment against the virus projected to hospitalize thousands of U.S. residents in the coming weeks.

April 7, 2020 - The FDA approved an Abbreviated New Drug Application for Hydroxychloroquine Sulfate Tablets USP, 200 mg.

April 2, 2020 - Henry Ford Health System led a national study to determine the drug's effectiveness in preventing COVID-19 disease.

March 29, 2020: Novartis Chief Executive Vas Narasimhan said his Sandoz generics unit's malaria, lupus, and arthritis drug hydroxychloroquine plans to donate up to 130 million 200 mg doses by the end of May, including its current stock of 50 million 200 mg doses. Narasimhan also said Novartis supports the clinical trials needed before the medicine against the coronavirus can be approved.

March 28, 2020:  The FDA issued an Emergency Use Authorization for the use of oral formulations of chloroquine phosphate and hydroxychloroquine sulfate for the treatment of COVID-19 when administered by a healthcare provider according to a valid prescription of a licensed practitioner as described in the Scope of Authorization (section II) of this letter.

March 25, 2020:  The FDA added hydroxychloroquine sulfate to category one under the Interim Policy on Compounding Using Bulk Drug Substances, Section 503B of the Federal Food, Drug, and Cosmetic Act.

March 25, 2020: The WHO urges countries to ensure the continuity of malaria service during the COVID-19 pandemic.

March 22, 2020: India's Secretary of Health stated that the National Task Force for COVID-19 disease officially recommends prophylactic hydroxychloroquine for healthcare workers and families of laboratory-confirmed positive COVID-19 patients.

January 7, 2019 - Study: Calcium pyrophosphate disease (CPPD) is caused by the deposition of calcium pyrophosphate (CPP) crystals in the joint tissues, particularly fibrocartilage and hyaline cartilage. Several mechanisms of action have been suggested for Hydroxychloroquine (HCQ) in the context of CPPD treatment, all of which signify its capability to immunomodulate and reduce inflammation. HCQ blocks T-cells' activity and reduces the release of various cytokines (interleukin-1, interleukin-6, and tumor necrosis factor-alfa). It has also been demonstrated to inhibit matrix metalloprotease activity in experimental animals. In a double-blinded, prospective six-month trial, HCQ was beneficial specifically for chronic CPPD-related arthropathies.

August 22, 2005: Chloroquine is a potent inhibitor of SARS coronavirus infection and spread.

March 1, 2015 - HCQ triggers the host defense machinery by inducing ROS- and MAVS-mediated innate immune activation against DENV infection and may be a candidate drug for DENV infection.

Plaquenil Antiviral Medication Clinical Trials

Clinical Trial NCT04341441: Will Hydroxychloroquine Impede or Prevent COVID-19 (WHIP COVID-19).

Clinical Trial NCT04332991: Outcomes Related to COVID-19 Treated With Hydroxychloroquine Among In-patients With Symptomatic Disease (ORCHID) (Phase 3).

Clinical Trial NCT04308668: Post-exposure Prophylaxis / Preemptive Therapy for SARS-Coronavirus-2 (COVID-19 PEP) (Phase 3)

Clinical Trial NCT04333654Hydroxychloroquine in Outpatient Adults With COVID-19 (Phase 1).Primary Objective: To assess hydroxychloroquine versus placebo effect on nasopharyngeal SARS-CoV-2 viral load in outpatient adults with COVID-19.

Clinical Trial NCT04321278: Safety and Efficacy of Hydroxychloroquine Associated With Azithromycin in SARS-CoV2 Virus (Phase 3).

Clinical Trials NCT04358068: Evaluating Hydroxychloroquine and Azithromycin's Efficacy to Prevent Hospitalization or Death in Persons With COVID-19.

Note: This content is aggregated from the CDC, WHO, clinical studies, and the Precision Vax news network. This information is fact-checked by healthcare professionals, such as Dr. Robert Carlson.