Spironolactone for FPHL: Are routine potassium blood tests needed?

Spironolactone (Aldactone) for Healthy Women with FPHL: Is Potassium Testing Needed?

Spironolactone is an oral antiandrogen that is sometimes used to treat female pattern hair loss. It is also used to treat acne and hirsutism.

In addition to being an antiandrogen, spironolactone is a a type of blood pressure pill and diuretic. Spironolactone acts on the kidney (in the distal convoluted renal tubule) to promote sodium and water excretion and to promote potassium retention.

Do patients using spironolactone for hair loss needed blood tests for potassium?

Previous recommendations had suggested that routine monitoring of serum potassium levels by having the patient periodically have blood tests performed was important. Recent studies have suggested this is not necessary for healthy women.

Layton and colleagues evaluated 10 randomized controlled trials (RCTs) and 21 case series pertaining to acne. The authors did not find that serum potassium was more likely to be elevated in healthy women using spironolactone for acne.

Plavanich and colleagues performed a retrospective study of healthy young women taking spironolactone for acne. The authors analyzed rates of hyperkalemia (high potassium) in 974 healthy young women taking spironolactone and also analyzed 1165 healthy young women taking and not taking spironolactone to obtain a profile for the baseline rate of hyperkalemia in this population.

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. The conclusion was that the rate of hyperkalemia in healthy young women taking spironolactone for acne is equivalent to the baseline rate of hyperkalemia in this population and that potassium monitoring is unnecessary for healthy women taking spironolactone for acne.

Studies of potassium levels in women using spironolactone for hair loss have not been done but there is no reasons to believe there is any difference. Routine potassium testing in healthy women is not usually necessary. 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 good candidates for spironolactone but if they are candidates they will require periodic potassium measurements.

Reference

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

Plavanich M et al. Low Usefulness of Potassium Monitoring Among Healthy Young Women Taking Spironolactone for Acne. JAMA Dermatol. 2015.