Spironolactone in the Treatment of Acne Vulgaris in Females

Background: There has been an increasing incidence in the prevalence of adult acne vulgaris ranging between 30-50%. Androgens play a significant role in the pathogenesis of acne. Recently, hormonal therapy has been advocated as a first line therapy for acne vulgaris among female patients who experience premenstrual flares, acne beginning or worsening in adulthood and for severe seborrhea. Spironolactone, an androgen receptor blocker, has long been used in the treatment of acne at doses 100-200mg/day. However, side effects like menstrual irregularities, breast tenderness, postural lightheadedness, nausea and hyperkalemia limit its use.

Objective: This study was therefore designed to determine the efficacy and tolerability of low dose spironolactone (50mg/day) used as an adjunct in the treatment of acne vulgaris among adult female patients. The secondary objectives were to determine and compare the reduction of acne lesion counts (noninflammatory, inflammatory and total acne lesions) among patients taking low dose spironolactone at 50 mg/day in combination with conventional acne treatments (topical and/or oral antibiotics) to those who are only taking conventional acne treatments alone after 16 weeks of treatment, to determine the time (in weeks) for the low dose spironolactone to show significant reduction of acne lesion count among adult female patients, and to determine the side effects of low dose spironolactone during its use among adult female patients with acne vulgaris.

Methods: A total of 62 patients were randomized to receive either conventional acne therapy alone or conventional acne therapy with low dose spironolactone (50mg/day) as an adjunct for 16 weeks. Patients must qualify with the inclusion and exclusion criteria prior to study entry. End points were the acne lesion count (noninflammatory, inflammatory, and total lesions), investigator’s and patient’s assessment of improvement. Adverse events of spironolactone was being monitored every 2 weeks. Significant improvement is defined as >75% reduction in total acne lesion count.

Results: Sixty two patients (29 control group, 33 treatment group) were randomized and received treatment. Patients ranged in age from 20 to 53 years (mean, 27.35 years), with mild and moderate acne. Both groups consisted of patients with acne confined to the chin, experienced premenstrual flares, and had recurrent acne, but new onset adult acne were more common in the treatment group. Both groups were associated with a reduction from baseline in total, inflammatory and noninflammatory lesions. The differences between groups in the change of comedones, inflammatory and total acne counts from baseline to weeks 2, 4, 6, 8, 10, 12, 16 were not statistically significant. The mean improvement rate in the total acne lesion count at week 16 from baseline for the control and the treatment groups were comparable at 82.38 (+ 22.29) and 77.99 (+ 32.04), respectively (P = 0.539). The estimated odds ratio of having good improvement rate of >75% in the total acne lesions count with spironolactone as an adjunct is 1.27 times higher than without taking spironolactone. Patients who had acne confined on the chin/jawline and adult onset acne showed greater improvement rate compared to those who did not take spironolactone (odds ratio 3.0 and 1.42 respectively). The investigator’s global assessment and the dermatology life quality index were statistically similar between the two groups. There was a significant increase in serum potassium levels at the end of the study period but the actual values were all within the normal values (3.5 to 5.5 mmol/L). The reported adverse effects of spironolactone include menstrual irregularities, breast tenderness, nausea, and postural lightheadedness. The odds of developing menstrual irregularities and breast tenderness were 4.04 and 5.12 while on a low dose of spironolactone at 50mg daily for 4 months.

Conclusions: In this study, spironolactone was associated with >75% improvement in the number of acne lesions among patients with adult onset acne and acne confined to the jawline and/or chin. Menstrual irregularities and breast tenderness are the most common side effects to be expected even at low doses of 25 to 50mg/day. However, the efficacy of using low dose spironolactone as an adjunct in the treatment of acne vulgaris among adult female patients was noted to be comparable with standard acne treatments; with a risk of developing menstrual irregularities and breast tenderness. The authors recommend that low dose spironolactone (25 to 50mg daily) may be used, for a period of 4 months with every 2 months monitoring of serum potassium, as an adjunct among patients with adult onset acne and those who have acne confined to the chin and/or jaw who were resistant to conventional therapy.

Author: Sy Stephanie, University of Santo Tomas – Manila, Philippines

Source of Information: Sy S. Poster. 20th Regional Conference of Dermatology (RCD) – Manila, Phillipines