Diuretics are most frequently used for hypertension and to remove excess fluid from the body. The use of diuretics can often cause the prescribing cascade. In this post, I’ll share 3 of my most common examples of diuretics and the prescribing cascade I’ve seen in practice.
Hydrochlorothiazide and Gout
Mrs. J is a 68-year-old with newly diagnosed hypertension. Her provider starts hydrochlorothiazide 25 mg daily, and her blood pressure improves nicely. A few months later, she develops pain and swelling in her big toe. Labs show elevated uric acid, and she’s diagnosed with gout. The provider adds allopurinol to lower her uric acid levels and naproxen to acutely manage the pain and inflammation..
What’s missed is that hydrochlorothiazide itself can raise uric acid and trigger gout flares (excellent board exam question). Now Mrs. J is taking another medication to treat a problem caused by the first one. A lower thiazide dose or switching to a different antihypertensive could have prevented the issue entirely.
Diuretics and Hypokalemia
Mr. S is a 74-year-old with heart failure and lower extremity edema. He’s started on furosemide 40 mg daily. The diuretic works well—his swelling improves, but a few weeks later, he’s feeling weak and lightheaded. Labs show low potassium. The provider prescribes potassium chloride tablets to replace what’s lost.
The problem is that the furosemide dose may be higher than necessary, and the potassium supplement just adds another pill and potential GI side effects. Reducing the diuretic dose or adding a potassium-sparing agent like spironolactone might fix the problem at its source. Needing the extra potassium is often a necessary evil while using loop and thiazide diuretics, but checking labs is also a great opportunity to assess if long-term use is necessary.
Diuretics and Urinary Frequency
Mrs. C is a 76-year-old with chronic heart failure and mild fluid retention. Her provider adds bumetanide 1 mg daily to help manage the swelling. A few weeks later, she reports bothersome urinary urgency and frequency, especially at night. Assuming it’s overactive bladder, the provider adds oxybutynin.
Now Mrs. C is taking a potent diuretic that increases urination—and another drug to counteract that effect. Oxybutynin brings its own risks (highly anticholinergic): constipation, dry mouth, and confusion in older adults. In this case, simply timing the diuretic earlier in the day or adjusting the dose might reduce nighttime urination without another prescription.
These cases are good reminders that not every new symptom deserves a new drug. Sometimes the best solution is to look back and see whether a medication already on the list is the real culprit. Changing timing, reducing dosages, and assessing long-term need are good ideas to try to avoid the prescribing cascade when using diuretics.
- 30 medication mistakes PDF
- 18+ Page Drug Interaction PDF
- 10 Commandments of Polypharmacy Webinar based on my experiences in clinical practice
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