Ask the Pharmacist

Q) I understand there has been a breakthrough in the treatment of COVID-19. Is this true and what can you tell me about it?

A) In what has been a year and a half of massive and relatively rapid breakthroughs when it comes to the COVID-19 virus, it appears we have hopefully reached a new milestone in our fight against this disease. Although rapid is not a word we think of and seems like an odd word for a pandemic that goes on and on, but in terms of scientific discoveries, they have been shockingly quick in their development.

The breakdown of the genetic sequencing of the virus and the development of multiple vaccines against it are two developments that come to mind. In recent news, two drugs developed in the United States appear to be extremely effective treatments against the virus in those who have contracted it.

There have been numerous drugs touted over the last 18 months as being possible treatments such as hydroxychloroquine, bleach with a special thanks to ex-President Trump for that gem of a recommendation, and the new rage with the anti-parasitic drug Ivermectin to name a few but none have withstood rigorous scientific scrutiny when it came time to prove both their effectiveness and their safety for use in humans. While it is still early, it appears that this is about to change.

Paxlovid developed by Pfizer and Lagevrio (molnupiravir) discovered by another giant of the pharmaceutical, Merck, in conjunction with Ridgeback Biotherapeutics have had such promising results from their respective clinical trials that the trials were ended early in order to get these drugs to market quicker. While this may sound dicey to some of us who do not like to see drugs rushed to market, it is a practice that has been used for decades based on ethics.

The theory is that if, in the midst of a trial, the data is so overwhelmingly positive, it becomes no longer ethical to continue to give half of the trial patients a placebo type of treatment when researchers are now sure that they will fare less well than those taking the active drug. This has been done in numerous cancer and cardiovascular treatments throughout the years.

Data from these trials has yet to be published but such is the burden of this disease in terms of mortality, morbidity and continued negative economic consequences that regulators such as Health Canada are already assessing the drugs to see if they should be approved and eventually purchased for use in Canadians. This is not surprising given the recent surge in cases in Canada, Russia and throughout Europe. As mentioned earlier, these two drugs are treatments and hence are given only after you have become infected with the virus, regardless of whether you have been vaccinated or not.

*Please note, these are not a substitute for vaccines which continues to be the front-line when it comes to battling this virus. Vaccines are preventative medicine, rather than reactionary. Vaccines prevent you from spreading it to others or from allowing the virus to have another chance to mutate into an even more contagious or lethal form.

In regards to these new treatments, they both come in the form of a pill which means they can be used in a home setting as opposed to infusion type treatments (which we are currently using now) which require either expensive equipment or administration in a hospital type setting. It also means they can be easily and cheaply transported and stored which will be of particular benefit in a country as vast and sparsely populated as Canada is.

Molnupiravir looks like it will be the first to market so we’ll focus on this drug today and discuss Pfizer’s entry next week. At this point in time, molnupiravir has already been approved in the UK and it is expected that it will be actively used in the next month or so. The US is still going over the data as are many European countries and one expects Health Canada is already actively looking into the situation as well.

Molnupiravir is not actually a new drug. It was first approved in the early 2000’s as a treatment for the influenza virus. It works by interfering with the virus’ ability to replicate itself (i.e. to reproduce) which helps to prevent the virus from achieving the numbers it needs to overpower your immune system and make you really sick. It does this by essentially tricking the virus. When a virus enters a human cell, it makes a copy of its RNA in order to begin its replication process. The drug mimics parts of this RNA so that the virus mistakenly uses the drug instead for this replication purpose resulting in errors being inserted into the genetic code of the virus’ offspring and preventing them from surviving.

Merck says that this process should allow the drug to be effective against new variants of the virus that may crop up in the future since it is not targeting specific parts of the virus that are subject to mutate. The drug is at a dose of 4 pills, twice a day for a total of 5 days. It is recommended that it be started as soon as possible as viruses replicate most rapidly at the time when people first start experiencing symptoms. The official recommendation is that the drug should be administered as soon as a positive COVID test has been confirmed, ideally within five days of symptom onset.

The drug has been shown in clinical trials to reduce the risk of hospitalization or death by about 50%. These are very good numbers, but do pale in comparison to the intravenous administration of monoclonal antibodies which are believed to be about 85% effective. The patient base that molnupiravir has been tested on are those who are exhibiting mild to moderate symptoms upon diagnosis but who are at high risk of becoming severely ill as the disease progresses such as the elderly, the obese or those with underlying medical conditions such as diabetes or heart disease.

In terms of raw numbers, out of 775 patients there were no deaths in the molnupiravir group and 7.3% required hospitalization whereas the group given a placebo type treatment saw a hospitalization rate of 14.1% and had 8 deaths. The drug worked consistently well across all the major variants of the virus such as Gamma, Delta and Mu. Against patients who were already severely ill, the drug produced disappointing results. This reemphasizes the importance of it being prescribed as early as is possible.

Merck did not report any serious side effects among the volunteers in its clinical trials and the most common complaints were mild headaches and fatigue which can be hard to distinguish between the symptoms of the virus itself.

As with any new drug, there is always a concern about side effects which may only appear years after the drug has been released. There are two that most researchers believe bear monitoring. One is its potential to cause the virus to mutate more frequently than it naturally tends to which may cause a more lethal strain to be released. The second deals with concerns with whether the drug might also target our own DNA as well which might increase the risk of cancer or have implications for those who are pregnant when they take it.

Next week we’ll discuss the other new drug, Pfizer’s Paxlovid, in detail along with just how much these drugs are expected to cost. For more information about these or any other health related questions, contact your pharmacist.