Serum Potassium Testing Among Users of Oral Spironolactone: Too Many Unnecessary Tests

Overtesting of Potassium is Common among Spironolactone Users.

Spironolactone is a common treatment for androgenetic alopecia in women.

Increased potassium levels among spironolactone users has been a concern among users in years gone by. Recent data suggests that in healthy women under 45 years of age, testing potassium levels makes little sense as rates of elevated potassium are no different than people who don’t use spironolactone. There may, of course, be benefits of potassium testing for women over 45 and some other groups - just not in younger healthy women. It seems that this new advice is not taking off very fast and many practitioners are still routinely sending patients off to the lab to have blood tests done while on spironolactone.

See Prior Articles:

Spironolactone for Hair Loss: Should we be measuring potassium levels or not?

Spironolactone for FPHL: Are routine potassium tests needed?


Barbier and colleagues recently examined whether or not health care practitioners are tuning in to these new practice recommendations by studying potassium measurements in over 108 000 women age 12-45 using spironolactone. There is some slight good news - but only some. In this cohort study, the overall proportion of women with potassium level monitoring decreased from 41% in 2008 to 38% in 2018. It seemed that some dermatologists were stopping their routine ordering of potassium but only a few. In 2008, 49 % of patients in dermatologist practices were routinely having their potassium monitored and this dropped to 41 % in 2018. Internists really hadn’t adopted the new practice recommendations and a similar proportion of their patients were having potassium checked in 2018 as 2008. Patients receiving care from advanced practice providers like nurse practitioners and physician assistants were more likely to have potassium monitoring in 2018 compared to 2008.

In this study, tens of thousands of women got tested for potassium levels when they didn’t need to. Around the world, the numbers are likely very high. Routine testing for potassium should not be the standard of care in young healthy women.

This particular study is important as it reminds us that the message has still not been efficiently delivered into the offices of health practitioners about the limited usefulness of routine potassium monitoring for patients on spironolactone.

A Simple Algorithm for Potassium Testing in Women Using Spironolactone

Reference

Barbieri et al. JAMA Dermatol. 2021