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Lately, we’ve been hearing a lot about using a drug called hydroxychloroquine in the fight against COVID-19. Hydroxychloroquine is not new. It’s been around since the mid-20th century. Since then it’s been used to prevent and treat malaria (in areas where mosquitos haven’t yet developed a tolerance) and to treat lupus and rheumatoid arthritis. But how could this decades-old medication work to defend us in the world’s current fight against the novel coronavirus? And, more importantly, is it safe and effective?
What is Hydroxychloroquine?
As stated above, hydroxychloroquine is a medication that has antimalarial properties. Because of this, it has historically been used in the treatment and prevention of malaria. Additionally, hydroxychloroquine belongs to a category of medications called disease-modifying antirheumatic drugs (DMARDs). It has immunomodulating effects. It inhibits inflammation and autoantibodies (antibodies that attack the self instead of an outside invader). In other words, it can be used to suppress an immune response. For this reason, it is used to treat lupus and rheumatoid arthritis.
Why Are We Hearing So Much About Hydroxychloroquine Now?
Recently, we have heard hydroxychloroquine being touted—prematurely—as a miracle cure for COVID-19 by many people in the public eye, including the president of the United States. The world is desperate for a treatment for this horrible virus. It’s easy to grab onto any ray of hope in our current pandemic. This is understandable. However, before we can claim that hydroxychloroquine is safe and effective as a treatment for infection with the novel coronavirus, more studies need to be done.
Why Do People Think Hydroxychloroquine Could be a Treatment for COVID-19?
There have been some studies done in petri dishes in labs (scientists call these studies in vitro studies) that have shown how hydroxychloroquine may be effective in preventing SARS-CoV-2 (the novel coronavirus) from infecting cells. Before going into that, however, it may be helpful to know how the virus enters the cell and causes so much damage.
Coronaviruses are called coronaviruses because they are surrounded by a crown-like ring of spike proteins, some of which serve as a type of ‘key’ that fits directly into a ‘lock’ (a receptor) that allows the virus entry into the cell. The specific receptor in this case is called the angiotensin-converting enzyme 2 (ACE2) receptor. Once inside the cell, the virus hijacks the host cell’s machinery to make more copies of itself.
There are two possible ways that have been seen in a lab environment (not in humans as of this writing) that hydroxychloroquine can disrupt the process by which the virus enters the cell and replicates itself. First, hydroxychloroquine has been shown to prevent the virus from gaining entry to the cell by preventing binding between the spike protein (the ‘key’) and the ACE2 receptor (the ‘lock’) in the first place.
The second way hydroxychloroquine could prevent the virus from infecting the cell is by incorporating zinc into the mix. Zinc prevents the virus from being able to effectively hijack the cell’s RNA-replicating machinery to create more virus. However, it’s very difficult for zinc to get into a cell. Hydroxychloroquine acts as a zinc ionophore. That is to say, hydroxychloroquine provides transportation across the cell membrane for the zinc. After the zinc gets inside, it can then prevent the virus from using the cell’s machinery.
It is important to emphasize here that the effects of hydroxychloroquine that are thought to be most effective against the novel coronavirus have been shown effective in a lab setting only. In order to show that hydroxychloroquine can be both safe and effective in the fight against COVID-19, more rigorous testing needs to be done in vivo (in actual living beings). In science, the gold standard by which medication safety and effectiveness is assessed is the randomized, double-blind placebo-controlled study.
What are the Dangers of Hydroxychloroquine?
More than one study assessing the effectiveness of hydroxychloroquine (and its older cousin chloroquine) in the treatment of COVID-19 has been stopped early because researchers found that the harms of using the drug outweighed the benefits. One of the harms is the potential for sudden cardiac death as a result of the drug disrupting the heart’s electrical system.
Another concern with using hydroxychloroquine to treat COVID-19 before it is proven safe and effective is that other patients who need it to treat their lupus or rheumatoid arthritis won’t be able to get it due to the possibility of drug shortages.
Is it Safe to Take Hydroxychloroquine During Pregnancy?
Hydroxychloroquine is used to treat lupus and rheumatoid arthritis in pregnancy. It is important to note that hydroxychloroquine does cross the placenta. However, several studies of the medication have not shown any increase in the rates of adverse effects for mother or baby. Additionally, other small studies have shown that hydroxychloroquine is excreted through breastmilk. These studies have not shown any increase in the rates of adverse effects for baby. It’s best to talk to your doctor about taking this, or any other, medication during pregnancy.