Sunday Morning Backgrounder: The SECOND Reason I Think Pfizer's AND Merck's Covid Pills Will See "About Even" Deployments...

While the Pfizer pill is (in smaller-scale studies) showing better risk-of-hospitalization data [or, greater efficacy, of one prefers] than Merck's, it should be noted that most people, in ordinary clinical settings, who contract the more/most dangerous forms of the COVID symptoms often have multiple other health issues -- which is (in part) why it can become so dangerous.

This in turn, leads to a quandry -- with the Pfizer pill: it will likely require a "co-dosing" with an older HIV drug, one that more generally slows ALL drugs' break-downs, inside the human body. But that co-dosed drug also interacts negatively with many common medications.

So, if the patient is on high blood pressure medications, or on a renal drug, the Pfizer pill may not be suitable for a COVID viral outbreak, as it might cause wild swings in the dosing profile of these other meds, in that patient's body. Merck's Lagevrio^® does not face this issue (due to a relatively-slight difference in chemical structure) -- so in these sicker, more "highly (other) medicated" Covid patients, it will more often be the drug of choice to avoid added risk of Covid hospitalizations. Here is some of the later learning, on it all:

. . .["A] requirement for Pfizer’s antiviral pill to be taken with ritonavir, a drug used to treat HIV, would make the treatment unsuitable for many people with pre-existing medical conditions, he added.

“Ritonavir, which has been used in HIV therapy for many years, is a drug that specifically inhibits the ability of the body to break down medicines,” said [Merck's] Barr. “The problem is that it’s incredibly non-specific. So there’s a whole host of medicines that people take, especially those medicines, unfortunately, that are associated with conditions that confer risk.”

A study published in the scientific journal Nature last week identified a “high overall frequency” of drug-to-drug interactions in high-risk Covid-19 patients in Spain treated with the antiviral drug lopinavir and ritonavir while in hospital. Such interactions were “alarmingly overlooked in the setting of the Covid-19 healthcare crisis,” concluded the authors of the study. . . .

So we should be confident that in younger, otherwise healthy people who get severe forms of Covid symptoms, the Pfizer pill will clearly be the go-to choice (i.e., a fairly unusual population of patients), but in cases where the sickest patients are on multiple other meds -- Merck's pill will likely be prescribed. Smiling -- into a quiet Sunday's fog, here. . . be excellent to one another.

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