Precision Antibiotic Dosing for Appendectomy (PANDA)

August 12, 2026 updated by: Manjunath Prakash Pai, University of Michigan

Aim 3 - Precision Coordination of Therapeutic and Prophylactic Antibiotics to Reduce Infection, Toxicity, and Emergence of Resistance Following Acute Abdominal Surgery

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.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

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 Type

Interventional

Enrollment (Estimated)

46

Phase

  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Michigan
      • Ann Arbor, Michigan, United States, 48108
        • Michigan Medicine

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

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 Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Other
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
No Intervention: Standard of Care
The current standard of care surgical prophylaxis regimen
Experimental: Cefoxitin
Administration of Cefoxitin 2000 mg within 30 minutes of incision to the existing standard of care intervention
Drug: Cefoxitin
Cefoxitin 2000 mg Bolus Injection

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Probability of Achieving Optimal Antibiotic Concentration in Appendix Tissue
Time Frame: 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.
4 hours

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Michigan

Collaborators

Agency for Healthcare Research and Quality (AHRQ)

Investigators

  • Principal Investigator: Manjunath Pai, PharmD, University of Michigan

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

February 28, 2025

Primary Completion (Actual)

July 31, 2026

Study Completion (Estimated)

September 30, 2026

Study Registration Dates

First Submitted

February 28, 2025

First Submitted That Met QC Criteria

February 28, 2025

First Posted (Actual)

March 6, 2025

Study Record Updates

Last Update Posted (Actual)

August 14, 2026

Last Update Submitted That Met QC Criteria

August 12, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • HUM00263447
  • R01HS027788 (U.S. AHRQ Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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