Once Again, Antibiotics Are Unnecessary for Acute Uncomplicated Diverticulitis

More data confirm that antibiotics do not improve outcomes, and some guidelines move toward limiting antibiotic use. Although antibiotics traditionally have been used to treat all patients with diverticulitis, high quality evidence during the past decade suggests they are  unnecessary for acute uncomplicated cases. In 2021, a randomized outpatient study added new data to support this conclusion.

In past studies, inpatients with acute uncomplicated diverticulitis have been randomized to receive antibiotics or not: Outcome data confirmed no differences in pain levels, complications requiring surgery, duration of hospitalizations, or readmission rates (Br J Surg 2012 Apr; 99:532;
Br J Surg 2017 Jan; 104:52; NEJM JW Gen Med Jul 1 2020 and Clin Gastroenterol Hepatol Mar; 19:503).

However, the question of whether hospitalization itself affected these findings was never resolved — in particular, did liberal administration of intravenous fluids affect study results? In the 2021 trial, re- searchers randomized healthy outpatients with acute uncomplicated diverticulitis to oral amoxicillin/ clavulanate or no antibiotic and reported the same findings: No differences in hospitalization rates, rates of emergency department visits, pain levels, or need for surgery (NEJM JW Gen Med Dec 1 and Ann Surg Nov; 274:435). Whether these findings will change current practice is unclear. Some widely used clinical references (e.g., UpToDate) continue to recommend that all diverticulitis patients receive oral or intravenous antibiotics. However, some guidelines now suggest that antibiotics be used “selectively rather than routinely” in uncomplicated cases and be reserved for patients with serious comorbidities, high inflammatory markers, or particularly dramatic imaging (NEJM JW Gen Med Apr 1 and Gastroenterology Feb; 160:906).

Meanwhile, in another 2021 study, researchers retrospectively compared outcomes among uncomplicated diverticulitis patients who received either metronidazole plus a quinolone or  amoxicillin/ clavulanate alone (NEJM JW Gen Med Apr 1 and Ann Intern Med Jun; 174:737). No differences in complications or outcomes were found, but among older patients (age, ≥65) the quinolone combination was associated with significantly higher risk for Clostridioides difficile infection. Clinicians who are uncomfortable abandoning their longstanding practice of administering antibiotics to diverticulitis patients might at least consider de-escalating their coverage
to the safer drug.
— Abigail Zuger, MD

UpToDate can be accessed at https://www.uptodate.com/contents/acute-colonic-diverticulitis-medical-management (subscription required)