What are the appropriate antibiotics (Abx) for the treatment of cholecystitis?

From the Guidelines

For cholecystitis, empiric antibiotic therapy should include coverage for enteric gram-negative organisms, enterococci, and anaerobes, with beta-lactam/beta-lactamase inhibitor combinations, such as piperacillin-tazobactam, being a recommended first-line option. The choice of antibiotic regimen is guided by the most frequently isolated bacteria, including Escherichia coli, Klebsiella pneumonia, and Bacteroides fragilis, as well as local antibiotic resistance patterns 1. In elderly patients with complicated acute cholecystitis, broad-spectrum antibiotic regimens are recommended to ensure adequate empiric therapy, which significantly affects outcomes in critical patients 1.

Some key considerations for empiric antibiotic therapy in cholecystitis include:

• Coverage for gram-negative aerobes, such as E. coli and Klebsiella pneumonia
• Coverage for anaerobes, such as Bacteroides fragilis
• Consideration of local antibiotic resistance patterns
• Use of broad-spectrum agents in severe infections or healthcare-associated cholecystitis
• Reassessment of the antimicrobial regimen daily to optimize efficacy, prevent resistance, and minimize toxicity 1

Alternative options for empiric antibiotic therapy in cholecystitis include:

• Cephalosporins-based regimens
• Carbapenem-based regimens
• Fluoroquinolone-based regimens (in case of allergy to beta-lactams)
• Glycylcycline-based regimen 1
• Ceftriaxone 1-2g IV daily plus metronidazole 500mg IV every 8 hours
• Ciprofloxacin 400mg IV every 12 hours plus metronidazole if there's a beta-lactam allergy

It is essential to note that treatment duration is typically 4-7 days, though shorter courses may be appropriate after source control with cholecystectomy, and antibiotics should be adjusted based on culture results when available 1. Prompt antibiotic therapy along with surgical intervention (cholecystectomy) when indicated is essential for optimal outcomes in acute cholecystitis.

From the FDA Drug Label

Tigecycline was evaluated in adults for the treatment of complicated intra-abdominal infections (cIAI) in two randomized, double-blind, active-controlled, multinational, multicenter studies (Studies 301 and 306) These studies compared tigecycline (100 mg intravenous initial dose followed by 50 mg every 12 hours) with imipenem/cilastatin (500 mg intravenous every 6 hours) for 5 to 14 days. Patients with complicated diagnoses including appendicitis, cholecystitis, diverticulitis, gastric/duodenal perforation, intra-abdominal abscess, perforation of intestine, and peritonitis were enrolled in the studies The preoperative administration of a single 1 gram dose of Ceftriaxone for Injection may reduce the incidence of postoperative infections in patients undergoing surgical procedures classified as contaminated or potentially contaminated (e.g., vaginal or abdominal hysterectomy or cholecystectomy for chronic calculous cholecystitis in high-risk patients, such as those over 70 years of age, with acute cholecystitis not requiring therapeutic antimicrobials, obstructive jaundice or common duct bile stones)

Antibiotics for cholecystitis include:

• Tigecycline
• Ceftriaxone These antibiotics have been studied in the treatment of complicated intra-abdominal infections, including cholecystitis 2, and as surgical prophylaxis for cholecystectomy 3.

From the Research

Antibiotic Use in Cholecystitis

• The use of antibiotics in patients with acute cholecystitis is a crucial aspect of treatment, as it helps prevent surgical complications and limits the systemic inflammatory response 4.
• The Surgical Infection Society recommends against routine use of peri-operative antibiotic agents in low-risk patients undergoing elective laparoscopic cholecystectomy, but recommends their use in patients undergoing laparoscopic cholecystectomy for acute cholecystitis 5.

Choice of Antibiotics

• The choice of antibiotic should be based on factors such as the severity of clinical manifestations, the onset of infection, and drug resistance 4.
• First-generation cephalosporins may be an appropriate choice for empirical antibiotics in mild-to-moderate acute cholecystitis without gallbladder perforation, as they are not inferior to second-generation cephalosporins for prophylaxis against postoperative infection 6.
• Cefepime has been shown to be equivalent to gentamicin and mezlocillin combination for treating patients with acute infections of the biliary tract 7.

Duration of Antibiotic Therapy

• The duration of antibiotic therapy should be limited to a maximum of four days, and perhaps a shorter duration in patients undergoing cholecystectomy for severe cholecystitis 5.
• In cases of severe acute cholecystitis, broad-spectrum antibiotics may be necessary, but the clinical outcomes were not inferior to those treated with narrow-spectrum antibiotics 8.

Bacterial Colonization and Resistance

• Patients with acute cholecystitis have a bile bacterial colonization rate of 35-60%, with the most frequently isolated microorganisms being Escherichia coli, Klebsiella spp., Streptococcus spp., Enterococcus spp., and Clostridium spp. 4.
• Antibiotic stewardship is crucial to prevent drug resistance and ensure the appropriate use of antibiotic agents 4.