MOA — Mechanism of action — gets bandied about a lot.
Drug reps love it. Saying your product is a “first-in-class MOA” sounds great as they hand you a glossy brochure. It also features prominently in print ads, usually with pics of smiling people.
It’s a good thing to know, too, both medically and in a cool-science-geeky way. We want to understand what we’re prescribing will do to patients. We want to explain it to them, too.
Dr. Allan M. Block
It certainly helps to know that what we’re doing when treating a disorder using rational polypharmacy.
But at the same time we face the realization that it may not mean as much as we think it should. I don’t have to go back very far in my career to find Food and Drug Administration–approved medications that worked, but we didn’t have a clear reason why. I mean, we had a vague idea on a scientific basis, but we’re still guessing.
This didn’t stop us from using them, which is nothing new. The ancients had learned certain plants reduced pain and fever long before they understood what aspirin (and its MOA) was.
At the same time we’re now using drugs, such as the anti-amyloid treatments for Alzheimer’s disease, that should be more effective than one would think. Pulling the damaged molecules out of the brain should, on paper, make a dramatic difference ... but it doesn’t. I’m not saying they don’t have some benefit, but certainly not as much as you’d think. Of course, that’s based on our understanding of the disease mechanism being correct. We find there’s a lot more going on than we know.
Like so much in science (and this aspect of medicine is a science) the answers often lead to more questions.
Observation takes the lead over understanding in most things. Our ancestors knew what fire was, and how to use it, without any idea of what rapid exothermic oxidation was. (Admittedly, I have a degree in chemistry and can’t explain it myself anymore.)
The glossy ads and scientific data about MOA doesn’t mean much in my world if they don’t work. My patients would say the same.
Clinical medicine, after all, is both an art and a science.
Dr. Block has a solo neurology practice in Scottsdale, Arizona.