Efficacy and Durability of Intravenous Ertapenem Therapy for Recalcitrant Hidradenitis Suppurativa

Importance Hidradenitis suppurativa (HS) is a debilitating follicular skin disorder in which bacterial colonization is typical. Oral antibiotic efficacy can be unreliable; however, selective intravenous antibiotics, specifically ertapenem, may provide favorable clinical outcomes. Objective To explore optimal course duration, efficacy, and patient satisfaction associated with intravenous ertapenem for HS. Design, Setting, and Participants This retrospective review of the medical records of 98 patients with HS between 2018 and 2022 measured and evaluated patient outcomes before and after treatment with intravenous ertapenem. Participants were followed up in a telephone survey assessing patient perspectives and satisfaction. All of those included in this study received medical care from the Albert Einstein College of Medicine's Montefiore HS Center. Exposures Patients were treated with 1 g of ertapenem that was self-administered at home through a peripheral intravenous central catheter using an elastomeric pump for 12 to 16 weeks. Antiandrogens and immunomodulatory biologic therapies initiated prior to ertapenem were maintained throughout the treatment course. Main Outcomes and Measures The primary outcomes, encompassing clinical severity (evaluated through the HS Physician Global Assessment score [a 6-point scale ranging from clear to very severe] and a numerical rating scale for pain [an 11-point scale in which a score of 0 indicates no pain and a score of 10 indicates the worst possible pain]) and markers of inflammation (such as leukocytes, erythrocyte sedimentation rate, C-reactive protein, and interleukin-6), were measured at baseline, the midcourse of intravenous ertapenem treatment, at the end of the course, and posttherapy. Bacterial abundance was also examined at these 4 points, and patient satisfaction was assessed during follow-up. Results A total of 98 patients (mean [SD] age, 35.8 [13.0] years; 61 [62.2%] female) with HS were treated with intravenous ertapenem. The self-reported racial distribution included 3 individuals identifying as Asian (3.1%), 59 as Black/African American (60.2%), 13 as White (13.3%), and 23 as either other or unknown (23.5%). Additionally, 24 participants (24.5%) reported Spanish/Hispanic/Latino ethnicity. The mean (SD) treatment duration spanned 13.1 (4.0) weeks, with posttherapy follow-up occurring after 7.8 (3.6) weeks. From baseline to posttherapy follow-up, significant reductions were found in the mean (SD) HS Physician Global Assessment scores (3.9 [1.0] vs 2.7 [1.2]; P < .001) and the numerical rating scale for pain (4.2 [3.3] vs 1.8 [2.7]; P < .001), C-reactive protein (5.4 [11.4] vs 2.4 [2.0] mg/dL; P < .001), interleukin-6 (25.2 [21.1] vs 13.7 [13.9]; P < .001), and leukocytes (11.34 [3.9] vs 10.0 [3.4]; P < .001). At follow-up, 76 patients (78.0%) participated in the telephone survey, where 63 (80.3%) reported medium to high satisfaction; further, 69 (90.8%) would recommend ertapenem to other patients. Conclusions and Relevance In this retrospective review of medical records and telephone survey, treating HS with intravenous ertapenem, administered for a mean of 13 weeks, was associated with improvement in clinical and inflammatory markers, as well as heightened patient satisfaction. Nonetheless, this approach should be monitored for the emergence of antimicrobial resistance given a longer than standard treatment course.