What is the management of diverticulitis when Co-amoxiclav (amoxicillin/clavulanic acid) fails?

From the Guidelines

When co-amoxiclav fails in treating diverticulitis, alternative antibiotic regimens should be initiated promptly, considering the severity of the disease and potential complications. The most recent and highest quality study, published in 2021 by Peery et al. 1, suggests that antibiotic treatment is advised in patients with uncomplicated diverticulitis who have comorbidities or are frail, who present with refractory symptoms or vomiting, or who have a CRP >140 mg/L or baseline white blood cell count > 15 × 10^9 cells per liter. Some key points to consider in the management of diverticulitis when co-amoxiclav fails include:

• Switching to a combination of ciprofloxacin 500mg twice daily plus metronidazole 500mg three times daily for 7-10 days, or trimethoprim-sulfamethoxazole (160/800mg) twice daily plus metronidazole 500mg three times daily, as suggested by the 2020 update of the WSES guidelines for the management of acute colonic diverticulitis in the emergency setting 1.
• For more severe cases requiring intravenous therapy, options include piperacillin-tazobactam 4.5g every 8 hours, meropenem 1g every 8 hours, or ceftriaxone 2g daily plus metronidazole 500mg every 8 hours, as recommended by the 2020 update of the WSES guidelines 1.
• Treatment failure may indicate complications such as abscess formation, which requires imaging (preferably CT scan) to identify, as stated in the 2020 update of the WSES guidelines 1.
• Abscesses larger than 4-5cm typically require percutaneous drainage alongside antibiotics, as suggested by the 2020 update of the WSES guidelines 1 and the 2017 WSES guidelines for management of intra-abdominal infections 1.
• Patients with persistent symptoms, peritonitis, obstruction, or perforation may need surgical intervention, as recommended by the 2020 update of the WSES guidelines 1 and the 2017 WSES guidelines for management of intra-abdominal infections 1.
• Ensuring adequate hydration, bowel rest as needed, and pain management throughout treatment, as well as follow-up evaluation within 48-72 hours of changing antibiotics to assess response, are crucial in the management of diverticulitis, as suggested by the example answer.

From the Research

Management of Diverticulitis when Co-amoxiclav Fails

• The management of diverticulitis when co-amoxiclav fails is a complex issue, and the evidence suggests that there are various treatment options available 2, 3, 4, 5, 6.
• A study published in 2021 found that treating diverticulitis in the outpatient setting with amoxicillin-clavulanate may reduce the risk for fluoroquinolone-related harms without adversely affecting diverticulitis-specific outcomes 4.
• Another study published in 2021 found that failure rates following nonoperative management of acute diverticulitis complicated by abscess did not significantly decrease over the past three decades 5.
• A systematic review published in 2022 found that the evidence on antibiotic treatment for uncomplicated acute diverticulitis suggests that the effect of antibiotics is uncertain for complications, emergency surgery, recurrence, elective colonic resections, and long-term complications 6.
• The use of alternative antibiotics, such as metronidazole-with-fluoroquinolone, may be considered in cases where co-amoxiclav fails, although the evidence suggests that there are no significant differences in outcomes between these antibiotics 4.
• In some cases, surgical intervention may be necessary, particularly in cases of complicated diverticulitis or when nonoperative management fails 3, 5.

Treatment Options

• Antibiotic treatment: alternative antibiotics, such as metronidazole-with-fluoroquinolone, may be considered in cases where co-amoxiclav fails 4.
• Surgical intervention: may be necessary in cases of complicated diverticulitis or when nonoperative management fails 3, 5.
• Nonoperative management: may be considered in cases of uncomplicated diverticulitis, although the evidence suggests that the effect of antibiotics is uncertain 6.

Factors to Consider

• Patient factors: age, comorbidities, and overall health status may influence treatment decisions 2, 3.
• Disease factors: severity of diverticulitis, presence of complications, and response to initial treatment may influence treatment decisions 3, 5.
• Treatment outcomes: recurrence, elective colonic resections, and long-term complications may be considered when evaluating treatment options 6.