EVALUATION OF THE EFFICACY AND SAFETY OF MEDICAL TREATMENT WITH LOWER DOSES OF SPIRONOLACTONE IN A COHORT OF PATIENTS WITH PRIMARY ALDOSTERONISM

Abstract

Objective: Treatment with mineralocorticoid receptor antagonists is recommended for patients with bilateral forms of primary aldosteronism or with unilateral forms unwilling or unable to undergo surgery, using spironolactone as the primary choice, with a suggested dose of 1 to 2 mg/Kg/day. In clinical practice, however, the dose prescribed has been progressively decreased to achieve a better tolerance of the drug and, consequently, a higher compliance to treatment. Our aim was to evaluate how the lowering of spironolactone dose could have impacted on arterial blood pressure control and on the prevalence of adverse effects. Design and method: We retrospectively included 394 patients with primary aldosteronism receiving a medical treatment with spironolactone, with a minimum follow-up of 1 month after the initiation of medical treatment. Patients were divided into two groups, according to the median prescribed dose of spironolactone in our population (50 mg, 25 – 75): subjects treated with >50 mg and patients treated with < = 50 mg of spironolactone daily. Results: The median follow-up after the introduction of spironolactone was 6 months, and 135 patients experienced spironolactone-related adverse effects (34.3%), with a higher proportion in men than in women (76.30% vs. 23.70%). The most frequently reported adverse effect was gynecomastia, followed by erectile dysfunction. Subjects receiving a dose >50 mg of spironolactone daily displayed a significantly higher prevalence of side effects (42.2%), while a prevalence of 30.5% was described in the < = 50 mg group. Patients in the lower dose group were treated with a higher number of anti-hypertensive drugs, especially diuretics. No statistically significant differences were seen between the two subgroups in blood pressure measurements at follow-up. Conclusions: Treatment with low doses of spironolactone could help achieve a better adherence in patients with primary aldosteronism, with a lower rate of adverse effects compared to patients treated with higher doses, with no differences in blood pressure control at follow-up. This goal could be achieved by prescribing a higher number of anti-hypertensive drugs. These findings could help the clinician in choosing the best therapeutical option for each patient.