New diagnostic methods for treating low sodium levels in patients on thiazide diuretics
Official title: Validation of Diagnostic Indices to Simplify Hyponatremia Therapy Assessment - A Randomized, Controlled, Parallel-group Clinical Trial in Hospitalized Patients on Thiazide Diuretics (THAT Study)
Run by University Hospital, Basel, Switzerland · NCT06381934 · Data updated 2026-11-12
This study is testing two new ways to help doctors figure out why patients on thiazide diuretics have low sodium levels, to see if it can lead to better treatment options.
Quick facts
| Study type | Interventional |
|---|---|
| Ages | 18 Years and up |
| Sex | All |
| Enrollment | 136 (estimated) |
| Sponsor | University Hospital, Basel, Switzerland Academic / other |
| Locations | 1 site (Basel) |
| Status | Recruiting |
| Started | May 6, 2024 |
| Main results expected | April 2027 |
| Study ends | April 2027 |
| Registry record updated | February 11, 2026 |
| Trial ID | NCT06381934 on ClinicalTrials.gov |
Is this trial a fit for you?
✓Likely a good fit
Ideal candidates include hospitalized patients aged 18 and older who are on thiazide diuretics and have low serum sodium levels.
✕Probably not a fit
Patients with severe symptomatic hyponatremia requiring immediate intervention or those with significant comorbidities may not benefit from this study.
A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.
What this trial studies
This study evaluates two new diagnostic parameters, strong apparent ion difference (aSID) and chloride and potassium levels in urine (ChU), to improve the differentiation of causes of hyponatremia in patients taking thiazide diuretics. The goal is to determine if these new indices can enhance the accuracy of diagnosis and treatment compared to current standard methods, which have shown poor performance. By prospectively implementing these parameters, researchers aim to provide better treatment strategies for hospitalized patients suffering from thiazide-associated hyponatremia.
Why it matters
Potential benefit: If successful, this study could lead to more accurate diagnoses and improved treatment options for patients with low sodium levels caused by thiazide diuretics.
How similar studies have gone: While the approach of using aSID and ChU is novel, previous studies have indicated potential benefits in differentiating causes of hyponatremia, suggesting a promising avenue for further investigation.
Who can join: the full rules
Show full inclusion / exclusion criteria
Inclusion Criteria: * Hospitalized patients presenting at University Hospital Basel * aged 18 years or older * able to give informed consent as documented by signature * with serum sodium level \< 133 mmol/l and serum osmolality \< 300 mOsm/kg * with treatment with thiazide or thiazide-like diuretic Exclusion Criteria: * symptomatic hyponatremia in need of 3% hypertonic solution or intensive care treatment * inability or contraindications to undergo the trial (i.e., any acute severe cardiovascular event requiring an immediate intervention) * decompensated liver cirrhosis CHILD C * decompensated heart failure NYHA III or higher * severe valve impairment * untreated adrenal insufficiency * severe kidney disease in need of dialysis * pregnancy or breastfeeding * end of life care * inability to follow the study procedures (i.e., language problem, dementia or critical illness).
Where it's running
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University Hospital Basel
Basel, Switzerland Recruiting
Study contacts
- Principal investigator: Laura Potasso, Dr. med. sc. — University Hospital, Basel, Switzerland
- Study coordinator: Laura Potasso, Dr. med. sc.
- Email: laura.potasso@usb.ch
- Phone: +41 61 328 58 76
Similar studies
Other studies for the same condition or treatment. Recruiting studies are listed first.
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Investigating urinary prostaglandin levels to predict thiazide-induced low sodium levels
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.
How to take part
- Review the eligibility criteria above with your treating physician.
- Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
- Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.