P111 A multicentre service evaluation highlighting the variable off-label prescribing practice of spironolactone in the management of hidradenitis suppurativa: the need for evidence-based guidelines

Abstract Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease that affects 1 in 130 people in the UK, with a predilection for women. Onset is often soon after puberty, suggesting hormones may be implicated in the pathogenesis. Initial treatment for mild-to-moderate HS typically includes topical and oral antibiotics combined with topical antiseptic washes. Spironolactone has also been used as an off-label treatment for female patients due to antiandrogenic effects, with various treatment regimens suggested in published literature. To date there have been no randomized controlled trials evaluating the use of spironolactone in HS. A retrospective service evaluation was conducted to review prescribing practices of spironolactone for HS in multiple centres in the UK, including one tertiary centre and three secondary care centres across a 24-month period from January 2022. In total, 62 female patients treated with spironolactone were identified. Hurley staging had been recorded for 52% (n = 32) of patients; of these, 31% (n = 10) had stage 1 HS, 47% (n = 15) had stage 2 and 22% (n = 7) had stage 3. All patients had been prescribed antiseptic washes and topical or oral antibiotics as first-line HS management. Most were prescribed spironolactone as an adjunct to their existing management, including oral antibiotics, metformin and adalimumab. Prior to spironolactone initiation, 39% (n = 24) of patients had baseline blood testing, and 16% (n = 10) had baseline blood pressure recorded. The dosing regimen varied significantly, with 6% (n = 4) of patients documented on 25 mg, 31% (n = 19) on 50 mg, 24% (n = 15) on 100 mg, 13% (n = 8) on 150 mg and 6% (n = 4) on 200 mg once daily. The remaining patients (n = 12) were documented as initiated on 50 mg once daily, increasing to 100 mg. Side-effects were documented in 13% (n = 8) of patients including nausea (n = 2), dizziness (n = 2), headache (n = 1), urinary frequency (n = 1), leg cramps (n = 1) and dry mouth (n = 1). Discontinuation of medication was recorded in 21% (n = 13) of patients, with inefficacy (n = 6), side-effects (n = 4), pregnancy (n = 2) and initiation of adalimumab (n = 1) documented as reasons. We conclude that there is significant variability in patient selection, monitoring and prescribing practices of spironolactone for HS across these UK sites. With a view to addressing the uncertainties outlined in the James Lind Priority Setting Partnerships for HS, we propose that a multicentre randomized controlled trial is needed to inform the evidence base and to produce clear UK guidelines on treatment with spironolactone in HS.