Photo: Iván Ernesto Reyes.
No matter what you read in the news, what that WhatsApp voicenote in your family group chat said, or what Donald Trump or Nicolás Maduro said on TV, there’s still no universally approved treatment against coronavirus.
What we have though, are potentially useful options… lots of them.
By Monday, March 24th, there were 71 drugs being studied as possible treatment candidates for COVID-19. Some of these are completely new and specifically designed for the new disease, many others are medications already approved and widely used for different ailments.
To understand why none of those has been approved to treat COVID-19, it’s important to take a look at the process behind drug development: in order for a medication to be used in humans, its chemical and physical characteristics, as well as its potential toxicity, must be determined with animal models, or isolated cells. If the medication proves it can do what it’s supposed to without being too dangerous, human trials can begin. Initially, it’ll be tested in healthy individuals, just to be absolutely sure that the medication is safe, and only then in a small number of sick patients before it can be scaled up and used in larger trials. If the evidence proves the drug is useful and safe in a clinical context, then it’ll be approved for that disease. If you want to try it for a different condition, you skip the first few steps, but you still need to conduct clinical trials.
This process can easily take around five years, but given the current crisis, it’s being sped up.
To understand why none of those has been approved to treat COVID-19, it’s important to take a look at the process behind drug development.
At this point, five treatments (not including the vaccine, which I’ll discuss in a different post) are in the last phase of evaluation: antivirals remdesivir, favipiravir and ritonavir, antimalarial chloroquine and specific antibodies against the virus.
Remdesivir, initially developed to treat Ebola disease, has shown to have some effect against SARS and MERS viruses, closely related to the SARS-cov-2 and was used to treat a patient in the United States. It’s currently being tried in China, Hong Kong, Singapore and South Korea, and although it’s not yet approved, the U.S. Center for Disease Control (CDC) has made it available for some critically ill patients.
Fapinavir, approved for treating influenza, proved to reduce the time the virus could be detected in infected patients and is currently being tried in China and Italy. Ritonavir, on the other hand, is widely used against HIV and was initially tried with another HIV drug, lopinavir. This combination (Kaletra) didn’t demonstrate any efficacy in large studies, but ritonavir is currently being tried combined with other medications.
Chloroquine and the very similar hydroxychloroquine have recently made headlines: the drugs have been used since 1947 to treat malaria and have shown activity against the new coronavirus, both in lab conditions and small clinical trials. Although the drug hasn’t been approved by the FDA for COVID-19 treatment, it’s being used in China and Italy, and a large clinical trial is expected to begin in New York this week.
Following Donald Trump’s touting of it last week, a man in Arizona died after consuming a fish tank cleaner that contained chloroquine phosphate.
This medication, however, is contraindicated in patients with certain heart conditions and diabetes. It can cause loss of vision upon prolonged use. Following Donald Trump’s touting of it last week, a man in Arizona died after consuming a fish tank cleaner that contained chloroquine phosphate. Also, the most commonly cited study to recommend its usefulness in the current pandemic has serious methodological flaws, and overuse of hydroxychloroquine in COVID-19 patients is causing shortages that limit its access to patients with lupus (which is also treated with the medication). The Venezuelan government has announced it will use it to prevent COVID-19, even though no studies evaluating its usefulness preventing the disease in healthy individuals have been carried out.
Antibodies against SARS-Cov-2 recovered from the blood serum of infected patients who survived have also presented very promising results, first in China and now in the U.S., after the FDA approved its use in clinical trials with severely ill patients.
Finally, interferon alfa, the “Cuban drug” Nicolás Maduro and many blogs around the internet have heavily publicized in the last days, is being tested in a clinical trial in China, but it’s still an experimental treatment. Maduro, however, announced Venezuela would import the medication, used for hepatitis C, to deal with the COVID-19 pandemic, and it has already been included in the treatment guidelines of the Venezuelan Health Ministry. The measure prompted a statement from the Venezuelan Academy of Medicine and the National Bioethics Center, saying there’s not enough evidence to recommend its use beyond an experimental context. A similar drug, interferon beta, is being tested in the UK.
And just in case you were wondering, no, lemongrass tea is not a potential treatment for COVID-19, despite being advertised as such on several official Twitter accounts of the Venezuelan regime.