P048 Type and durability of antibiotic therapy among patients with chronic antibiotic dependent pouchitis
Authors: Kimberly Weaver , Millie Long , Hans Herfarth , Edward Barnes 
Published: July 2019

BACKGROUND:
The management of chronic antibiotic dependent pouchitis (CADP) is associated with significant morbidity and burden to patients with an ileal pouch-anal anastomosis (IPAA). When individuals fail to respond to standard antibiotic therapy for pouchitis, little guidance is available in choosing subsequent antibiotic regimens. We performed a retrospective study to evaluate specific antimicrobials as well as duration of therapy among patients treated for CADP in our multidisciplinary IBD center.

METHODS:
We identified patients with CADP between January 1, 2009 and December 1, 2016. Patients diagnosed with Crohn’s disease of the pouch and acute antibiotic responsive pouchitis were excluded. For each individual with CADP, we analyzed the type and duration of up to 4 antibiotic regimens. Standard descriptive statistics are presented, including medians and interquartile ranges (IQR) for duration assessments and Wilcoxon-rank sum testing for comparisons of duration of antibiotic therapy.

RESULTS:
A total of 288 patients were evaluated for pouch related disorders during the study period. From the initial population, 90 (31%) were excluded due to a diagnosis of Crohn's disease of the pouch and 75 (26%) were excluded due to a diagnosis of acute antibiotic responsive pouchitis. In total, there were 123 patients (53% male, mean age at time of IPAA 40.9 years) who were diagnosed with CADP. Most patients underwent a 2-stage IPAA and had pancolitis prior to colectomy. In the majority of patients (93/123; 75%), the first antibiotic regimen consisted of a fluoroquinolone alone (43%) or a fluoroquinolone in combination with either metronidazole (30%) or another antibiotic (2%). Metronidazole was used in 15%, and other antibiotics in 10% of the patients. Of the 123 patients, 93%, 76%, and 59% needed a second, third, or fourth antibiotic regimen, respectively. The use of fluoroquinolones alone or in combination decreased to 54%, 48%, and 40% of patients for the second, third, and fourth regimen. In particular, amoxicillin/clavulanate, sulfamethoxazole/trimethoprim, rifaximin and doxycycline were increasingly used in the third and fourth antibiotic approach (31% and 42%, respectively). The duration of the different antibiotic regimens varied, but fluoroquinolones alone were given for a significantly longer duration during the first 4 consecutive regimens compared to other antibiotics indicating a better persistence of therapy (regimen 1 median fluoroquinolone duration 32 weeks vs others 7.5 weeks (IQR 4–36), P < 0.001; regimen 2 median 20 weeks vs 8 weeks (IQR 4–28), P = 0.038; regimen 3 median 21 weeks vs 8 weeks (IQR 4–36), P = 0.005; regimen 4 median 20 weeks vs 10 weeks (IQR 4–20), P = 0.011).

CONCLUSION(S):
In a retrospective cohort of patients with CADP, we found that standard therapy with a fluoroquinolone alone or in combination was most common as the initial treatment for CADP. Although fluoroquinolones in particular demonstrated significant longevity, over time the proportion of the population treated with alternative antibiotic regimens such as amoxicillin/clavulanate, sulfamethoxazole/trimethoprim, doxycycline, and rifaximin increased presumably due to loss of response to standard therapy. Further studies are needed to individualize the therapeutic approach and determine the optimal antibiotic regimen with greatest durability and long-term response for this challenging patient population.