Precision Antibiotic Dosing for Appendectomy

Phase 1

Active, not recruiting

• Conditions: Appendicitis (Diagnosis)
• Interventions: Drug: Cefoxitin

• Registration Number: NCT06860802
• Lead Sponsor: University of Michigan

Brief Summary

This research is studying a drug called cefoxitin already approved by the Food and Drug Administration (FDA) to reduce the risk of infection after surgery to remove an appendix. Researchers are studying a large group of people to continue to learn how best to dose antibiotics. This research will compare the current standard treatment which is a single dose prior to surgery to a new method that includes adding another dose of cefoxitin within 30 minutes of starting the surgery. This study will measure cefoxitin concentrations in blood, fat, and appendix tissue samples to compare the standard dosing method to our new method. This information will help us figure out the right dose of this drug to prevent infection after surgery to remove an appendix.

Detailed Description

This interventional, phase 1 study aims to improve surgical site infection (SSI) prevention in patients undergoing appendectomy for uncomplicated appendicitis. Despite standard antibiotic prophylaxis, SSI rates remain high, with a pelvic abscess risk of 9.4%. Current prophylactic antibiotic regimens may not achieve optimal tissue concentrations, especially in fat and appendix tissue.

This study will evaluate the probability of target attainment (PTA) of cefoxitin, cefuroxime, and metronidazole in plasma, subcutaneous fat, and appendix tissue. A cohort of 46 adult patients will be randomized to receive standard-of-care antibiotics with or without an additional cefoxitin dose. Antibiotic concentrations will be measured in collected blood, fat, and appendix samples.

The study's primary objective is to determine whether a supplemental cefoxitin dose improves PTA compared to standard prophylaxis. Population pharmacokinetic modeling will validate the intervention's effectiveness in optimizing antibiotic exposure and reducing SSI risk. The results may inform future precision antibiotic dosing strategies for appendectomy and other acute care surgeries.

Primary Outcome Measure:

Probability of achieving 50% time above 8 mcg/mL (cefuroxime or cefoxitin) in appendix tissue between intervention and standard care groups.

Study Design:

Randomized, interventional, phase 1 study Enrollment: 46 participants Inclusion: Adults (\>18 years) undergoing appendectomy for acute appendicitis Exclusion: Pregnant individuals, prisoners, patients with perforation or abscess This study seeks to improve perioperative antibiotic management, reducing SSI rates while minimizing unnecessary antibiotic exposure and resistance development.

Study Timeline

• Status Verified: 2025-02
• Study Start: 2025-02-28
• Study First Submitted: 2025-02-28
• Study First Submitted QC: 2025-02-28
• Last Update Submitted: 2025-02-28
• Study First Posted: 2025-03-06
• Last Update Posted: 2025-03-06
• Primary Completion: 2026-06-30
• Study Completion: 2026-09-30

Recruitment & Eligibility

• Status: ACTIVE_NOT_RECRUITING
• Sex: All
• Target Recruitment: 46

Inclusion Criteria

• Diagnosis of acute appendicitis and plan to undergo appendectomy at the University of Michigan

Exclusion Criteria

• Prisoners
• Patients that are pregnant
• Patients with perforation or abscess on CT Scan

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Cefoxitin	Cefoxitin	Administration of Cefoxitin 2000 mg within 30 minutes of incision to the existing standard of care intervention

Primary Outcome Measures

Name	Time	Method
Probability of Achieving Optimal Antibiotic Concentration in Appendix Tissue	4 hours	The probability of achieving 50% time above 8 mcg/mL (cefuroxime or cefoxitin) in appendix tissue in the intervention compared to the non-intervention (standard of care) arm.

Trial Locations

Locations (1)

Michigan Medicine; 🇺🇸 Ann Arbor, Michigan, United States