From the Guidelines
For patients with diverticulitis who are allergic to penicillin, the most recent and highest quality study recommends that antibiotics can be safely omitted in patients with a first episode of uncomplicated (Hinchey 1a) acute left-sided colonic diverticulitis 1. When antibiotic treatment is necessary, the regimen usually includes broad-spectrum agents with gram-negative and anaerobic coverage. Some key points to consider in the treatment of diverticulitis in patients allergic to penicillin include:
- For mild to moderate uncomplicated diverticulitis, a combination of trimethoprim-sulfamethoxazole (Bactrim DS) 1 tablet twice daily plus metronidazole 500 mg three times daily for 7-10 days is recommended 1.
- Alternatively, ciprofloxacin 500 mg twice daily plus metronidazole 500 mg three times daily for 7-10 days can be effective 1.
- For more severe cases requiring hospitalization, intravenous options include clindamycin 600 mg every 8 hours plus aztreonam 1-2 g every 8 hours, or a carbapenem like ertapenem 1 g daily if there's no cross-reactivity with your penicillin allergy 1. It's essential to determine the type of penicillin allergy you have, as some patients with mild reactions may tolerate cephalosporins. These antibiotic combinations are designed to cover both gram-negative bacteria and anaerobes that commonly cause diverticular infections. In addition to antibiotics, treatment should include a clear liquid diet initially, gradually advancing as symptoms improve, adequate hydration, and pain management. If symptoms worsen or don't improve within 2-3 days, seek medical attention immediately as surgical intervention may be necessary. The high mortality associated with sepsis requires clinicians to maintain a high index of clinical suspicion, in the conditions that predispose to sepsis in high-risk patients 1. Antibiotic therapy covering Gram-negative bacilli and anaerobes is advised in patients with radiological documented uncomplicated acute diverticulitis associated with systemic manifestations of infection or in high-risk patients such as immunocompromised patients, elderly patients, and those with comorbidities 1.
From the FDA Drug Label
WARNINGS BEFORE THERAPY WITH CEFOTAN® IS INSTITUTED, CAREFUL INQUIRY SHOULD BE MADE TO DETERMINE WHETHER THE PATIENT HAS HAD PREVIOUS HYPERSENSITIVITY REACTIONS TO CEFOTETAN DISODIUM, CEPHALOSPORINS, PENICILLINS, OR OTHER DRUGS IF THIS PRODUCT IS TO BE GIVEN TO PENICILLIN-SENSITIVE PATIENTS, CAUTION SHOULD BE EXERCISED BECAUSE CROSS-HYPERSENSITIVITY AMONG BETA-LACTAM ANTIBIOTICS HAS BEEN CLEARLY DOCUMENTED AND MAY OCCUR IN UP TO 10% OF PATIENTS WITH A HISTORY OF PENICILLIN ALLERGY.
The FDA drug label does not provide a recommended treatment for diverticulitis in patients allergic to penicillin. It only discusses the potential for cross-hypersensitivity between penicillins and cephalosporins, such as cefotetan, in patients with a history of penicillin allergy 2.
From the Research
Treatment Options for Diverticulitis
When a patient is allergic to penicillin, alternative antibiotic treatments must be considered. The following options are available:
- Metronidazole plus a fluoroquinolone, such as ciprofloxacin, can be used to treat diverticulitis in patients with a penicillin allergy 3
- Rifaximin has been shown to be effective in obtaining symptom relief in patients with uncomplicated diverticular disease and improving symptoms after acute colonic diverticulitis 4
Considerations for Antibiotic Use
The use of antibiotics in diverticulitis treatment is still a topic of debate. Some studies suggest that antibiotics may not be necessary for uncomplicated diverticulitis, as they do not reduce the duration of the disease or prevent recurrence 5, 6
- A systematic review found that the effect of antibiotics on complications, emergency surgery, recurrence, and long-term complications is uncertain, with low-certainty evidence 5
- Guidelines recommend selective use of antibiotics in patients with uncomplicated diverticulitis, and non-operative management with intravenous antibiotics for complicated diverticulitis 6
Outpatient Treatment
Outpatient treatment with oral antibiotics can be safe and effective for patients with uncomplicated diverticulitis, as long as they have tolerance to oral intake and no severe comorbidity or lack of family support 3
- A study found that ambulatory treatment of uncomplicated acute diverticulitis is applicable to most patients, with only a small percentage requiring admission due to persisting symptoms 3