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

Potassium Levels and Spironolactone: Measuring May be More Relevant for Women over 45.

Spironolactone is an oral medication often used off label for treatment of androgenetic alopecia in women. Previous recommendations in patients using spironolactone for acne (not hair loss) suggested that routine monitoring of serum potassium levels was important. However, more recent studies have suggested this is not necessary for healthy women. This includes a 2017 study by Layton and colleagues that evaluated 10 randomized controlled trials (RCTs) and 21 case series pertaining to acne.

See Previous Article: Spironolactone and FPHL: Are routine measurements necessary?

Similar conclusions were found by Plavanich and colleagues in a retrospective study of healthy young women taking spironolactone for acne. The findings of the study were that young women receiving spironolactone had a hyperkalemia rate of 0.72%, equivalent to the 0.76% baseline rate of hyperkalemia in the general population.

Although there is increasing evidence that measuring potassium levels in young healthy women who do not use any other medications is probably not necessary, a key question is whether we should or should not be measuring potassium levels in women in the late 40s, 50s (and beyond) who are prescribed the drug.

Thiede and colleagues recently reported data on potassium levels in 124 women both before and after spironolactone initiation. 112 women were in an 18 to 45 years age group, and 12 were in a 46 to 65 years age group. All women had potassium levels within normal limits before starting the drug. Interestingly, 17 % of women in the 46 to 65 years age group had high potassium levels (hyperkalemia) after starting spironolactone compared with less than 1 % of women 18 to 45 years of age.

Routine monitoring of potassium levels is probably not necessary in young healthy women who don’t take other medications.

Conclusion

Overall, this was a very small study and there were only 12 patients in the older age group which limits how we interpret this data. Nevertheless, the study has important lessons which are likely relevant not only for women using spironolactone for acne but hair loss as well. First, routine potassium testing in young healthy women is probably not necessary. Second, women with cardiovascular disease, kidney disease, diabetes and women taking certain medications that affect potassium levels (ie potassium sparing diuretics) may or may not be deemed good candidates for spironolactone in the first place but if they are they will certainly require periodic potassium measurements. Third, even healthy women over 45 could potentially be at increased risk of hyperkalemia from spironolactone and one should at least consider whether or not monitoring is warranted.


References
Thiede RM et al. Hyperkalemia in women with acne exposed to oral spironolactone: A retrospective study from the RADAR (Research on Adverse Drug Events and Reports) program. Int J Womens Dermatol. 2019 Apr 25;5(3):155-157.

Layton AM et al. Oral Spironolactone for Acne Vulgaris in Adult Females: A Hybrid Systematic Review. Am J Clin Dermatol. 2017.