In the fast-paced world of urgent care, each patient brings a unique challenge—one recently took me back to my early days of medical practice. I had an appointment with a patient taking warfarin, an old blood thinner.
Warfarin is a tricky medicine to manage for both patients and doctors. It can be lifesaving but also be poisonous. It is also used as rat poison after all. Small changes in patients’ diet can throw off the balance between its medicinal and toxic nature. We track this equilibrium with a test known as the International Normalized Ratio (INR), which measures the time it takes for blood to clot. This patient’s INR was elevated, and it was clear his warfarin dosage needed tweaking—a task I hadn’t undertaken in years, thanks to the march of medical progress and a team-based approach to care at The Permanent Medical Group.
I was getting nervous. Even when I was managing warfarin regularly, it is relatively complicated and very easy to make mistakes. Then it hit me: eight years back, I had developed an app specifically for this challenge. Simply input the patient’s warfarin dose and INR, and the app calculates the next steps.
Problem solved!
These days, when solving a problem, I often wonder, how would ChatGPT in this context. I had to try it.
provide expert level answer. Calculate new warfarin dosing using the AAFP algorithm. Use 2.5 mg tabs.
current INR 4.1. INR goal 2-3
current warfarin weekly schedule
Monday: 2.5 mg
Tuesday: 5 mg
Wednesday: 5 mg
Thursday: 5 mg
Friday: 2.5 mg
Saturday: 5 mg
Sunday: 5 mgTo get answers, get answers in medicine without too many disclaimers, ask for expert level answer.
The current weekly warfarin schedule is as follows (in mg):
Monday: 2.5
Tuesday: 5
Wednesday: 5
Thursday: 5
Friday: 2.5
Saturday: 5
Sunday: 5
This totals to 30 mg of warfarin per week.
For an INR of 4.1, the AAFP algorithm would typically recommend holding a dose and reducing the weekly dose by 10-20%. However, given the complexity of warfarin dosing and the potential for serious bleeding risks, it's important to individualize the dosing plan based on the patient's history, risk factors, and the clinician's judgment.
If we were to reduce the weekly dose by 15% as a midpoint adjustment, we would calculate the new weekly dose as follows:
New weekly dose = Current weekly dose - (Current weekly dose × 0.15)
New weekly dose = 30 mg - (30 mg × 0.15)
New weekly dose = 30 mg - 4.5 mg
New weekly dose = 25.5 mg
Now, we need to distribute this new weekly dose across the week using 2.5 mg tablets. The goal is to keep the dosing as consistent as possible on a day-to-day basis while considering the tablet size.
Here's one way to distribute the new weekly dose:
Monday: 2.5 mg
Tuesday: 2.5 mg
Wednesday: 5 mg
Thursday: 2.5 mg
Friday: 2.5 mg
Saturday: 5 mg
Sunday: 5 mg
This schedule gives us a total of 25 mg, which is as close as we can get to the 25.5 mg target using 2.5 mg tablets without splitting them.You notice the recommendations are slightly different. This is not a ChatGPT hallucination. Simply there are different versions of the algorithm.
It took me 1 month to write WarfarinApp. It took me couple of minutes to engineer the PROMPT. Let’s do a back of the envelope calculation here of the jump in productivity. Let’s say it took me 40 hours to develop this calculator and 2 minutes to engineer the PROMT. That’s a 1,200 X jump in productivity. It’s clear where the economic growth in the coming years will come from.