Investigating urinary prostaglandin levels to predict thiazide-induced low sodium levels

Urinary Prostaglandin as a Potential Predictive Marker for Thiazide-induced Hyponatremia: a Prospective Cohort Study (The PROPHECY Study)

Observational University Hospital, Basel, Switzerland · NCT05542056

This study is trying to see if measuring a specific substance in urine can help predict if people starting thiazide diuretics will develop low sodium levels.

Quick facts

Study typeObservational
Enrollment232 (estimated)
Ages18 Years and up
SexAll
SponsorUniversity Hospital, Basel, Switzerland Academic / other
Locations3 sites (Móstoles and 2 other locations)
Trial IDNCT05542056 on ClinicalTrials.gov

What this trial studies

This observational study aims to determine if baseline urinary prostaglandin E2 (PGE2) concentrations can predict the risk of thiazide-induced hyponatremia (TIH) in patients starting thiazide or thiazide-like diuretics. Patients will be screened and included if they are newly prescribed these medications, and their urinary PGE2 levels will be measured before treatment and again after four weeks. The study will involve follow-up visits to monitor sodium levels and assess any changes in medication dosage. The goal is to identify a potential predictive marker for TIH, which could help in managing patients at risk.

Who should consider this trial

Good fit: Ideal candidates are adults aged 18 and older who are newly prescribed thiazide or thiazide-like diuretics.

Not a fit: Patients who have taken thiazide or thiazide-like diuretics in the past month or those with existing hyponatremia will not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to better identification of patients at risk for thiazide-induced hyponatremia, allowing for more personalized treatment plans.

How similar studies have performed: While the role of urinary PGE2 in TIH is suggested, this approach is relatively novel and has not been extensively tested in prior studies.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Newly prescribed thiazide or thiazide-like diuretic
* ≥ 18 years of age
* Informed Consent as documented by signature

Exclusion Criteria:

* Intake of thiazide or thiazide-like diuretic in the preceding month
* Hyponatremia (plasma sodium \<135 mmol/L) at baseline
* Acute infectious / inflammatory disease (CRP ≥ 20 mg/L \[1, 11\])
* Symptomatic urinary tract infection
* Chronic treatment with NSAID and / or NSAID intake 48 hours prior to urine sampling at visit 1 and 2 (intake of acetylsalicylic acid will be no exclusion criteria)
* End of life care, no informed consent or inability to follow the procedures of the study, e.g., due to language barriers, psychological disorders, dementia

Where this trial is running

Móstoles and 2 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.
Conditions Thiazide-induced HyponatremiaThiazideThiazide-like diureticsHyponatremiaProstaglandin E2Urinary PGE2 concentrationPlasma sodium levelUrinary prostaglandins
Last reviewed 2026-06-13 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.