Many readers of the Post must be taking angiotension receptor blockers (ARBs) for high blood pressure. As products these are tagged with names ending in -sartan. My personal poison is candesartan, but theres a losartan, a valsartan and many others. Well call them sartans here to cut down on the acronyms.

In my column for Saturdays paper I gave a whimsical overview of hypothetical treatments for COVID-19, and I forgot to so much as mention the sartans. Strange error for me to make. But it could be because these drugs have undergone a strange swing in reputation in the COVID era.

For a few weeks physicians and researchers studying COVID and the nasty little cuss that causes it, SARS-CoV-2, were nervous about the sartans (and their older cousins, the ACE inhibitors). It had quickly become apparent that SARS-CoV-2, like the classic SARS virus Canadians know too well, uses the natural enzyme ACE2 to penetrate cell walls in the lung and possibly other organs.

ACE2 is angiotensin converting enzyme 2. It is part of the fiendishly complicated renin-angiotensin hormone system that the kidney uses to tell the rest of the body to send it enough blood to do its job. This is the same system that the sartans fool with to lower your blood pressure, so there was an immediate question of interaction between the drug, the enzyme and the virus that exploits the enzyme.

Sartans increase ACE2 expression: they upregulate it, in the language of pharmacologists. This sounds bad if youre frightened of a virus that uses ACE2 opportunistically to turn your lungs into hamburger. It sounded bad to enough family doctors that medical authorities had to put out advisories telling them not to run wild and start switching their high blood pressure patients away from sartans.

This now seems like a good call, because the latest thinking subject to change at any moment, no doubt is that sartans might actually help fend off the virus. Original SARS was shown in mice to actually downregulate or reduce ACE2 while exploiting it; this caused high blood pressure and lung failure, making the virus more or less the opposite of a sartan. Taking sartans actually appears to give you more ACE2 receptors, and that is, paradoxically, what you might want. Rather than increasing the attack surface for the virus, it gives you more receptors to spare so that the system keeps working.

Well, there are about two dozen people on Earth who understand this stuff and Im not one of them. But the concept seems credible to those who studied original SARS closely. They even thought about using sartans as a treatment for SARS when there still seemed some danger it would run amuck, as SARS-2 is doing.

Pictured taken March 26, 2020. REUTERS/Jose Luis Gonzalez

This is all theory (an untested mechanistic hypothesis, grumble the Olympian deities of evidence-based medicine), but it has found some empirical support. As the COVID virus was executing its cavalry charge through the city of Wuhan and Hubei province, a group of Chinese doctors were retrospectively studying the medication histories of persons who had both COVID and chronic high blood pressure. They wanted to check whether sartans and other pills for hypertension were bad. In their data, sartans came out looking very good, with users having significantly lower odds of developing severe COVID. It is an effect strong enough to have shown up in a fairly small universe of 511 patients.

I am not promising that the sartans will save us, but if you are a fellow user, you can feel slightly more comfortable about having to take em

It could still be due to chance, and Im sure none of you are keen on trusting that two and two make four if someone in mainland China says so. But doctors in other countries are now working on replicating the Chinese effort in a similar way, and in countries with state-provided medicare and good electronic records, signs of sartan protection (or harm) could be sought, very quickly, at the level of whole national populations. (I know it sounds as though Ive described Canada in that sentence, but forget that: we are a shambles. Think Denmark.) I am not promising that the sartans will save us, but if you are a fellow user, you can feel slightly more comfortable about having to take em.

National Post

Twitter.com/ColbyCosh

View original post here:
Colby Cosh on COVID-19: Sartans at Thermopylae? Blood pressure meds vs. the coronavirus - News Lagoon

Comments are closed.