Evaluating antibiotic use after appendicitis surgery

Complex And Simple Appendicitis: REstrictive or Liberal Post-operative Antibiotic eXposure (CASA RELAX) Using Desirability of Outcome Ranking (DOOR) and Response Adjusted for Duration of Antibiotic Risk (RADAR) -A Randomized Controlled Trial

PHASE4 · University of California, San Francisco · NCT05966454

This study is testing whether a shorter course of antibiotics after appendicitis surgery is safe and effective for patients compared to the usual longer treatment.

Quick facts

PhasePHASE4
Study typeInterventional
Enrollment145 (estimated)
Ages18 Years and up
SexAll
SponsorUniversity of California, San Francisco (other)
Drugs / interventionschemotherapy
Locations1 site (San Francisco, California)
Trial IDNCT05966454 on ClinicalTrials.gov

What this trial studies

This study aims to assess the safety, efficacy, and feasibility of a shorter course of post-operative antibiotics for patients undergoing surgery for appendicitis. It is a single-center, randomized controlled trial that will compare standard antibiotic treatment durations to determine if reducing antibiotic exposure can minimize adverse effects while maintaining patient safety. Participants will be monitored for outcomes related to their recovery and any complications that may arise from the differing antibiotic regimens.

Who should consider this trial

Good fit: Ideal candidates for this study are adults aged 18 and older who are scheduled for an appendectomy.

Not a fit: Patients who are immunocompromised, pregnant, or have certain medical conditions such as heart failure or active infections may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to reduced antibiotic exposure for patients, minimizing side effects while ensuring effective treatment.

How similar studies have performed: Other studies have explored antibiotic use in appendicitis treatment, but this specific approach to reducing post-operative antibiotic exposure is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

Age ≥ 18 years

* Age ≥ 18 years
* Planned appendectomy (laparoscopic or open)
* Working telephone number or reliable method to contact patient after hospital discharge

Exclusion Criteria:

* Unable to consent
* Pregnant Women
* Prisoners
* Immunocompromised as determined by clinical team, or patients actively receiving steroids, chemotherapy, or immunosuppressing medications (for example tacrolimus), or patients with active hematologic malignancy affecting the immune system, leukopenia, or end-stage AIDS
* Heart failure
* Allergy to bupivacaine
* Unlikely to comply with treatment or follow-up
* Inpatient consultation for appendicitis
* Clinically suspected of sepsis based on Sepsis-3 definition
* Current use of antibiotics for other indications
* Type 1 Diabetes or uncontrolled hyperglycemia
* Surgeon preference
* Patient preference
* Research team unavailable

Where this trial is running

San Francisco, California

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Appendicitis

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.