Spironolactone Side Effects and Management
Common Side Effects
- Hyperkalemia is one of the most common and potentially serious side effects, especially in elderly patients and those with renal impairment, according to the European Society of Cardiology 1, 2
- Worsening renal function can occur, particularly in patients with pre-existing kidney disease, as reported by the European Heart Journal 1, 3
- Menstrual irregularities occur in 15-30% of women, with higher risk at doses of 200mg/day, according to the American Academy of Dermatology 4, 5
- Breast tenderness affects 3-5% of women and up to 10% of men compared to placebo, as noted by the European Heart Journal 1, 4
- Gynecomastia (breast enlargement) in men is dose-dependent and may necessitate switching to eplerenone, according to the European Journal of Heart Failure 2, 6
Risk Factors and Monitoring
- Patients with renal impairment, elderly patients, and those with concomitant use of ACE inhibitors, ARBs, or NSAIDs are at highest risk for hyperkalemia, as reported by the European Heart Journal and the European Journal of Heart Failure 1, 2, 4, 5
- Monitoring of renal function and serum electrolytes is recommended before starting treatment, at 1 and 4 weeks after initiation, and after any dose increase, according to the European Heart Journal 1, 3, 6
Management of Side Effects
- If potassium rises to >5.5 mmol/L, the dose should be halved and monitored closely, as recommended by the European Heart Journal 1, 3
- If potassium rises to ≥6.0 mmol/L, spironolactone should be stopped immediately and hyperkalemia treated, according to the European Journal of Heart Failure 2, 3
- For men with breast tenderness or enlargement, consideration should be given to switching to eplerenone, as noted by the European Journal of Heart Failure 2, 3
Special Populations
- Spironolactone is pregnancy category C, with potential risk to male fetus due to anti-androgenic properties, as reported by the American Academy of Dermatology 5
- Long-term studies have not shown serious illnesses attributable to spironolactone, and large cohort studies have not confirmed increased cancer risk, according to the American Academy of Dermatology 5, 7