I had an excellent chance to use my Pharmacology this week while visiting my octogenarian grandparents.
I stumble into the kitchen where Grampi has already made coffee since he’s been up since dawn. I mumble good morning and he pounces.
Grampi: What do you know about Prilosec and Coumadin?
kati: Wow. Um. Can I get my coffee first? Let’s see. Prilosec is cimetidine, yes? Over the counter medication for heartburn? an H2 receptor blocker? Okay, I’m waking up now.
Coumadin is warfarin, a blood thinner. You’re taking it to keep clots from forming because of your atrial fibrillation (when the atria quiver instead of pumping efficiently). Clots are bad, they could mean strokes or pulmonary emboli, so we’d like to prevent them.
But according to my textbook, cimetidine and warfarin are bad business together, because they both are metabolized by the same enzymes in the liver. And I can’t remember at 7am if cimetidine ramps up the enzymes (lowering the active levels of drugs) or slow the metabolism of those enzymes (raising the levels of active warfarin). I do remember that there’s a pretty strong caution not to use them together if it’s avoidable, because one of them affects the level of the other.
And I remember that last night you said that your docs were having a tough time getting your INR stabilized between 2 and 3 (INR measures how the warfarin is working, how it is affecting the clotting factors of the blood). So, no, Grampi, in my two semesters under my belt student nurse opinion, you should not take Prilosec and Coumadin unless your doc specifically says it’s okay. And even then, I’d like to know why she thinks it’s okay.
Grampi: Hmmph. You are learning something at nursing school, aren’t you! Here - look at the rest of this. Now, why am I taking…
It was a little scary to realize that I’ve already taken a certain role in the family, only two semesters into nursing school. It’s the same role that Grampi was in while he was a practicing veterinarian (”What do we do about this weird red spot on Muffin’s belly?”), but it’s not one that I was prepared to assume until I graduated.
Last January, when my friend who is in the midst of a chemo regimen for metastatic breast cancer started throwing out names of drugs and interactions and cautions, and said “Well, I’m sure you know about this already”, I had to admit that no, no I didn’t know any of that. But now I can talk with her about the recent switch from one drug to another, and the whys and hows of that change.
I also know that I could have stammered that I had no idea about Prilosec and Coumadin and we would have had a lovely conversation about the front page of the paper, but I knew that stuff! And that’s a great feeling - that I didn’t just learn it for the test - that the knowledge is in there, retrievable upon command. Perhaps because it is so new to me, I can pretty easily translate it out of medical jargon and into plain English. And that is a skill that I hope I never lose, because patient education and the ability to communicate clearly with patients is absolutely essential to how I want to practice as a nurse.
It’s nice to know that I felt pretty comfortable doing patient education on P450 enzymes in my grandfather’s kitchen, and I’m not the least bit ashamed that I ran upstairs after my first cup of coffee and pulled up my powerpoint notes on warfarin on my laptop to make sure I had told him the right thing*.
* According to my notes, cimetidine strongly inhibits hepatic metabolizing enzymes, therefore drug levels of these substrates (one of which is warfarin) will rise (and in the case of warfarin, increase the risk of bleeding and blows one’s INR out the target range).