It happened again. A patient was on bumetanide for heart failure. It worked well in the beginning but seemed to be losing its punch over time. Plus we were concerned about lowish potassium levels.
So, I thought I went over my logic pretty well: Add spironolactone, which works differently and is potassium sparing.
A few days later my patient reported minimal weight loss and no improvement in his leg swelling or shortness of breath.
I started thinking out loud:
“Okay, so you’re taking one spironolactone and two Bumex now, right?”
“Oh no, I stopped the Bumex, because you said it wasn’t working.”
“Well, I think it was doing something, but it wasn’t working like it did in the beginning, and your potassium was starting to drop. So I thought the combination would probably work better for you.”
“Okay, I can do that.”
“Yeah, why don’t you, and call me after the weekend with your weight and an update on your swelling and your breathing.”
“Roger that”, he said. As I hung up, I thought to myself: “Why do people always assume I stop instead of add?”
The way my brain works, if you have a partial response with one drug, you keep that and add something else. If that works like a charm, you can taper or stop the first drug and maybe titrate the effective new one upward. But it can be a risky gamble to stop a partially effective drug and start sumething unproven – I mean, things could get worse in a hurry with that kind of strategy.
The only time I stop one drug completely and start another is if the patient doesn’t tolerate the first drug or if there is absolutely no benefit from the first one. Of course, I know that hypertension, heart failure and many other conditions usually require several drugs in order to achieve good control.
Hypertension patients in particular are often disappointed when they end up on three or more drugs. I tell them there are three drug combination pills out there just because it is so common to need several drugs to treat a stubborn medical condition.
So, anyway, I need to do a better job describing how my thinking goes: Keep the partially effective drug until the new one proves to be effective, then consider a full switch.
You’d think after 42 years in this business I wouldn’t have patients musinderstand me like that.
I need to do a PDSA on that one – I’ll need to do one for my Board recertification process anyway.
https://acountrydoctorwrites.blog/2019.03.29/pdsa-for-dummies
A Country Doctor Writes: 
Love your columns- I want to add to your point in this case. Heart failure is a lot like hypertension in that treatment is additive. In fact we talk about “GDMT” – guidance-directed medical therapy – an umbrella for an ever-lengthening list of medications that have been shown to incrementally improve heart failure survival. One of those is spironolactone, so a perfect choice in this situation as an add-on. I highly recommend, if you’re going to do one of those CMEs, learn about some of the newer heart failure treatments as they can make a tremendous difference to your patients.
respectfully, Nanette Bishopric