What is the appropriate antibiotic regimen for treating an acute episode of diverticulitis in an outpatient setting?

For an outpatient treatment of an acute episode of diverticulitis, the recommended antibiotic regimen is co-amoxiclav 500/125 mg three times daily for 5 days ¹.

Alternatively, if penicillin allergy or co-amoxiclav is unsuitable, options include cefalexin 500 mg twice or three times daily for 5 days plus metronidazole 400 mg three times daily for 5 days ¹.

Other alternatives are trimethoprim 200 mg twice daily for 5 days plus metronidazole 400 mg three times daily for 5 days ¹.

Use of ciprofloxacin in combination with metronidazole is also an option, but only if switching from IV ciprofloxacin with specialist advice, with ciprofloxacin 500 mg twice daily for 5 days ².