All drugs are poisons, and that’s OK
http://scienceblogs.com/insolence/2016/04/07/all-drugs-are-poisons-and-thats-ok/
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Another aphorism that I distinctly remember from later in my medical school experience was delivered on the very first day of my pharmacology class. Within the first five minutes the professor told us that all medications were poisons. They all interfere with normal cellular processes in some way. The ones we use as physicians just interfere with cellular processes in a way that can be beneficial in disease, and, quoting Paracelsus, he noted that the dose makes the poison.
So, yes, all medications are poisons in that they poison an enzyme or other biomolecule. (Look for a quack near you to quote mine that statement by saying, for instance, Orac says all medications are poisons and leaving out the rest of the sentence.) Ill give you an example: Aspirin. Aspirin, as many of you know, is acetylsalicylic acid. This particular molecule irreversibly inhibits an enzyme called cyclooxygenase (COX), which is involved in the production of mediators of inflammation, among other things. The exact details arent important, such as how aspirin inhibits the COX1 version more than COX 2 or how it does so by attaching an acetyl chemical group to the active site of the enzyme. The point is that aspirin permanently inactivates an enzyme. It poisons the cell. Thats how it works. In fact, when used as a blood thinner, aspirin permanently poisons a certain kind of cell, namely the platelet. Because a platelet doesnt have a nucleus, it cant make more COX. What it has when its made is all that it will ever have, and if that COX is irreversibly blocked, that platelets function is impaired for the rest of its lifespan. Again, without getting too technical, thats how aspirin works as a blood thinner. Its an antiplatelet drug.
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As noted above, whenever a physician treats a disease or condition with a drugor any other treatment, for that matterits a question of balancing risks with benefits. All real physicians know that. Its what they are trained to do. Its only in the fantasy world of deluded idiots like Mike Adams, Joe Mercola, antivaccinationists, and the usual assortment of quacks and cranks that there are medications or treatments for illness that have real therapeutic effects that dont also have risks and side effects. In some cases, these side effects and risks can be serious. Even when true, that doesnt invalidate or otherwise render useless the treatment and its therapeutic effects.
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All drugs are poisons, and thats OK. They couldnt work if they werent poisons. Its the nature of the poisonand the dosethat determines their usefulness, and all drugs have risks to go along with their benefits. Damn that nuance."
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A very good read, indeed.