As the coronavirus pandemic worsens, medical scientists and researchers are looking for anything that might prevent, or at least treat the disease. At least three major pharmaceutical companies are working overtime to develop vaccines. Meanwhile, findings reported in the journal Clinical Infectious Diseases indicate that a drug first developed almost seven decades ago may be able to stop the virus.
Hydroxychloroquine, sold under the brand name Plaquenil, is part of a class of medications known as quinolines. By itself, quinoline has few uses; however, various derivatives of the chemical, including quinine, are useful in the prevention and treatment of malaria. Additionally, hydroxychloroquine is used to treat auto-immune disease such as lupus and rheumatoid arthritis. It is also cheap: a month’s supply costs approximately $25 in the U.S.
In vitro testing carried out in China was performed, using “vero cells” (a lineage originally isolated and developed from cells obtained from the kidney of the African green monkey) infected with the coronavirus. In a letter published in Cell Discovery, the authors – most of whom work at the Chinese Academy of Sciences in Wuhan, where the outbreak was first reported – predicted that hydroxychloroquine “…has a good potential to combat the disease.”
A French research team obtained similar results when they tested the medication on volunteer hospital patients. In those clinical trials, patients received a daily intravenous dose of 600 milligrams, combined with azithromycin (Zithromax), an antibiotic used for the treatment of bacterial infections and venereal diseases. By the end of the sixth day of treatment, all 20 patients who received the combination therapy tested negative for the virus.
The Chinese research team recommends that coronavirus be treated with an initial dosage of 400 milligrams twice a day, followed by a maintenance dose of 200 milligrams twice daily for four days.
If further research produces similar results, hydroxychloroquine could prove to be a fast, reasonably safe, and inexpensive way to beat back the coronavirus epidemic. It would not be the first time that an old medication has been adapted to combat new and emerging illnesses. Patients suffering from Lyme disease, which infects approximately 38,000 Americans each year, have been found to respond well to treatment with dapsone (Aczone), a medication used for leprosy since the 1940s.
The use of established medications that already have regulatory approval can be of great advantage since the side effects and risks are known, and inexpensive generic versions are usually available. Nonetheless, although results so far are promising, it will require clinical testing on a much larger scale before the effectiveness of hydroxychloroquine against the coronavirus can be fully evaluated.