Hyperkalemia rare in transgender adolescents prescribed spironolactone
An analysis of transgender teens prescribed spironolactone showed that only 2.2% developed hyperkalemia after initiating therapy, with all cases resolving upon repeat measurement irrespective of spironolactone dose, according to findings published in the Journal of the Endocrine Society.
“All cases of hyperkalemia we identified occurred within the first 6 months of starting treatment,” Yee-Ming Chan, MD, PhD, director of the disorders of sexual development program and attending physician in the division of endocrinology at Boston Children’s Hospital, and colleagues wrote. “Despite monitoring for up to 7 years in patients taking spironolactone, we did not identify any additional cases of hyperkalemia. This observation suggests that if there is no evidence of hyperkalemia in the early treatment period, there is no increased risk with duration of spironolactone exposure.”
In a retrospective chart review, Chan and colleagues analyzed data from 85 gender-diverse adolescents seen in the gender management service program at Boston Children’s Hospital from 2007 to 2017 who were prescribed spironolactone. Researchers defined hyperkalemia as a serum potassium concentration of at least 5 mmol/L. Patients underwent 269 potassium measurements, including 80 measurements before the initiation of therapy and 189 measurements performed during spironolactone treatment (mean number of measurements per patient, 3.2). Doses ranged from 25 mg per day to 400 mg per day, with a mean daily dose of 105 mg per day. Most patients (86%) were using spironolactone as an adjunct to estrogen.
Within the cohort, eight potassium measurements in six patients exceeded 5 mmol/L, with two such measurements in the same patients determined to be hemolyzed by the laboratory, for a rate of hyperkalemia of 2.2%. The researchers observed that all cases of hyperkalemia occurred early in the treatment course (less than 6 months after initiating spironolactone). No measurements exceeded 6 mmol/L.
Among patients with hyperkalemia, none had symptoms, according to researchers, and those with elevated potassium levels had normal levels after repeat measurements. The researchers also found that larger doses of spironolactone were not associated with a higher risk for hyperkalemia and observed a trend toward lower serum potassium concentrations with increasing time taking spironolactone.
“Although this association between potassium measurements and treatment duration may have been caused by the resolution of hyperkalemia in affected subjects, it also raises the possibility that there is renal accommodation to mineralocorticoid antagonism that leads to a slightly lower potassium set point and thus a lower risk for hyperkalemia over time,” the researchers wrote. “Renal accommodation may also explain why we did not see an effect of higher spironolactone doses on serum potassium concentrations and why all cases of hyperkalemia were early, transient and self-resolved.”
The researchers noted that close potassium monitoring beyond the first 6 months of spironolactone therapy should be reserved for patients with medical comorbidities or those who are taking medications that may impair renal potassium handling. – by Regina Schaffer
Disclosures: The authors report no relevant financial disclosures.