There have only been a few, very small anecdotal studies that show a possible benefit of the drugs, hydroxychloroquine, and chloroquine, to relieve the acute respiratory symptoms of Covid-19 and clear the virus from infected patients.
Chloroquine phosphate, when used without a prescription and supervision of a healthcare provider, can cause serious health consequences, including death.
Clinicians and public health officials should discourage the public from misusing non-pharmaceutical chloroquine phosphate (a chemical used in home aquariums).
Clinicians should advise patients and the public that chloroquine, and the related compound hydroxychloroquine, should be used only under the supervision of a healthcare provider as prescribed medications.
The Centers for Disease Control and Prevention (CDC) has become aware of two individuals who ingested non-pharmaceutical chloroquine phosphate, a chemical for aquarium use that is commercially available for purchase at stores and through internet websites.
One of the individuals died shortly after arrival to the hospital. The second individual was critically ill with severe gastrointestinal symptoms and cardiac conduction abnormalities.
Upon recovery, the surviving individual reported to the media that they ingested the product to prevent infection with SARS-CoV-2, which causes coronavirus disease 2019 (COVID-19), after seeing information on the medical use of chloroquine on television.
The product in their possession was in powder form inside a 2.2-lb. container and labeled “for Ornamental Fish Use Only”.
CDC is also aware of unconfirmed media reports that these commercially available aquarium-use chemicals may be out of stock due to potential increased demand by the public.
And health experts warn the drugs’ well-known side effects could become more commonplace with much wider use.
In particular, they say, patients with existing heart problems or taking certain drugs such as anti-depressants that affect heart rhythm are at risk of a fatal episode.
Experts recommend screening before the drugs are prescribed to prevent drug-related deaths.
“The concern really is if we’re talking millions of patients, then this issue of drug-induced sudden cardiac death is absolutely going to rear its ugly head,’’ said Dr. Michael Ackerman, a pediatric cardiologist, and professor at the Mayo Clinic College of Medicine and Science.
Long-term use of the drugs also is associated with a form of vision loss called retinopathy, but the use of the drugs to fight the virus in an infected patient is only for a few days.
The FDA’s emergency authorization does not cover longer-term use of the drugs to prevent the coronavirus infection, a practice that has become more commonplace as doctors have prescribed the drugs “off label” in response to the pandemic.
“It is reasonable to believe that chloroquine phosphate and hydroxychloroquine sulfate may be effective in treating covid-19,” the FDA’s chief scientist, Denise Hinton, wrote in the letter granting emergency approval.
Novartis and Bayer are contributing millions of doses of the drugs to the federal government, which will distribute them via the Strategic National Stockpile. The extraordinary action came at the request of the Biomedical Advanced Research and Development Authority, a division of the Department of Health and Human Services.
Many hospitals and doctors have already been prescribing the anti-malarial drugs for weeks.
The surge in demand has sapped supplies of hydroxychloroquine, which has been used to treat lupus and rheumatoid arthritis. Patients suffering from those diseases have been unable to get their prescriptions filled in some parts of the country because of the run on the drugs as well as hoarding, according to health experts.