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Optimizing antibiotic dosing in critically ill patients with kidney function assessment

Optimization of Beta-lactam Dosing in Critically Ill Patients With Suspected or Documented Antimicrobial Resistant Gram-Negative Infections With Cystatin-C (OPTIMIZE-GNI)

Phase 4 Interventional National Institute of Allergy and Infectious Diseases (NIAID) · NCT06709521

This study is testing if a new way to measure kidney function can help doctors give the right amount of antibiotics to critically ill patients with tough infections.

Quick facts

PhasePhase 4
Study typeInterventional
Enrollment200 (estimated)
Ages18 Years and up
SexAll
SponsorNational Institute of Allergy and Infectious Diseases (NIAID) NIH
Locations10 sites (Torrance, California and 9 other locations)
Trial IDNCT06709521 on ClinicalTrials.gov

What this trial studies

This study evaluates how well Cystatin C and its derived equations can predict the pharmacokinetics of the antibiotics meropenem and cefepime in critically ill patients with suspected or documented antimicrobial-resistant Gram-negative infections. It compares these predictions to traditional methods based on serum creatinine levels. Patients will receive iohexol, which serves as a gold standard for measuring kidney function, to help assess the accuracy of the new methods. The study aims to improve antibiotic dosing strategies in this vulnerable population.

Who should consider this trial

Good fit: Ideal candidates are critically ill adults aged 18 and older with suspected or documented antimicrobial-resistant Gram-negative infections receiving meropenem or cefepime.

Not a fit: Patients with documented hypersensitivity to iohexol or contrast agents will not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to more accurate antibiotic dosing, improving treatment outcomes for critically ill patients with bacterial infections.

How similar studies have performed: Other studies have shown promise in using alternative biomarkers for kidney function assessment, but this specific approach is novel.

Eligibility criteria

Show full inclusion / exclusion criteria 
Inclusion Criteria:

1. Age \>/=18 years at the time of enrollment.
2. Residing in an ICU.
3. Documented or suspected Antimicrobial Resistant (AMR) Gram-negative infection for which the prospective participant is receiving meropenem or cefepime as part of their clinical management.
4. Expectation that the prospective participant will reside in the ICU and receive meropenem or cefepime for the duration of the study, and that all study procedures will be completed.
5. Expectation that IV access will be sufficient for drug infusion and either IV or arterial access will be sufficient to allow for all protocol-required blood sampling to occur.
6. The prospective participant, or their legally authorized representative (LAR), is able and willing to provide signed informed consent

Exclusion Criteria:

1. Prospective participant has a documented hypersensitivity or allergic reaction to iohexol, any contrast agents, or iodine.
2. Prospective participant has a documented prior history of severe cutaneous reactions to iohexol, any contrast agents, or iodine.
3. Prospective participant received iohexol on the calendar day of enrollment or the expectation that they will receive iohexol for clinical care (i.e., Standard of Care \[SOC\]) during the study.
4. Prospective participant had a major surgery within one calendar day prior to enrollment.
5. Prospective participant had a recent (within 6 months) burn involving \> 25% of total body surface area.
6. Prospective participant had a penetrating injury within one calendar day prior to enrollment.
7. Prospective participant is currently receiving or is expected to receive any type of renal replacement therapy including hemodialysis or extra corporeal membrane oxygenation, during study period.
8. Prospective participant has a documented diagnosis of diabetes with a serum creatinine (SCR) obtained for clinical care purposes (i.e., SOC results) \>3 mg/dL during screening.
9. Prospective participant has documented severe thyrotoxicosis as noted in medical records during screening.
10. Prospective participant is homozygous for sickle cell disease as noted in medical history/records.
11. Prospective participant has a documented diagnosis of hepatorenal syndrome as noted in medical records during screening.
12. Prospective participant is anuric\* for \>/ = 1 calendar day during screening AND has any one of the following documented conditions as noted in medical history/records:

    * Pheochromocytoma
    * Myelomatosis
    * Multiple myeloma
    * Paraproteinemia \*Anuria is defined as urine production \<100 mL in a calendar day
13. Prospective participant is pregnant or breastfeeding.
14. Prospective participant received or is expected to receive albumin from one calendar day prior to enrollment to end of study period.
15. Prospective participant received or is expected to receive \>/= 3 units of any blood product other than platelets from one calendar day prior to enrollment to end of study period.
16. Any condition that, in the judgment of the investigator, precludes participation because it could affect the prospective participant's safety.

Where this trial is running

Torrance, California and 9 other locations

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 → Find more trials like this →
Conditions Bacterial InfectionAMRBeta-lactamCefepimecystatin-CeGFRGram-negativeIohexol
Last reviewed 2026-06-09 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.