Treatment With Indapamide in Patients With Post-Surgical Hypoparathyroidism (HYPOCARE treat)

The aim of this study is to investigate the effect of daily treatment with Indapamide for 14 days on urinary calcium excretion in patients with post surgical hypoparathyroidisme.

Study Overview

• Status: Recruiting
• Conditions: Hypoparathyroidism Post-surgical
• Intervention / Treatment: Drug: Placebo; Drug: Indapamide 1.5 MG SR

Detailed Description

The aim of this study is to investigate the effect of daily treatment with Indapamide for 14 days on urinary calcium excretion in patients with post surgical hypoparathyroidisme.

Patients will do weekly blood sampling and 24 hour urine collection every second week.

• Study Type: Interventional
• Enrollment (Estimated): 24
• Phase: Phase 4

Contacts and Locations

• Study Contact: Name: Sarah Thornhøj, MD; Phone Number: +4540491821; Email: sarthorn@rm.dk

Study Locations

• Denmark
  • Aarhus, Denmark, 8200
    • Recruiting
    • Department of Endocrinology and Internal Medicine
    • Contact: Phone Number: 20257127; Email: sarthorn@rm.dk

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Chronic post surgical hypoparathyroidism diagnosed > 1 year ago
2. Age ≥ 18 years
3. Require treatment with active vitamin D ≥ 1 µg/day
4. Ionized plasma calcium between 1.15-1.25 mmol/L
5. 25(OH)D vitamin ≥ 50 nmol/L
6. Plasma magnesium > 0.65 mmol/L
7. Able to read and understand Danish
8. Willing and able to sign the informed consent form

Exclusion Criteria:

1. Estimated glomerular filtration rate (eGFR) < 30 ml/min/1.73 m3
2. Active cancer or former (except thyroid and basal cell skin) cancer treatment < 1 year ago
3. Pregnancy, pregnancy plans, or breastfeeding < 1 year ago
4. Abnormal arterial pressure at time of screening defined as symptomatic hypotension or systolic blood pressure < 100 mmHg
5. Plasma potassium < 3.5 mmol/L

6. Any current disease that might affect the calcium metabolism such as but not limited to:

   1. Recent prolonged immobility
   2. Untreated diabetes (HbA1c > 53 mmol/mol)
   3. Severe liver disease or hepatic encephalopathy
   4. Untreated thyroid disease
7. Current disease that might affect gastrointestinal absorption
8. Use of medications such as lithium or diuretics within 4 weeks prior to start of treatment
9. Known allergy or sensitivity to Indapamide, its excipients or sulfonamides
10. Known galactosemia, lactase deficiency, or glucose-galactose malabsorption

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Indapamide; 14 days with active drug Indapamide 1.5 mg/day	Drug: Indapamide 1.5 MG SR; 14 days treatment with indapamide 1.5 mg/day compared to placebo
Placebo Comparator: Placebo; 14 days with placebo	Drug: Placebo; 14 days treatment with placebo

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Urinary calcium excretion	investigate the effect of daily treatment with Indapamide for 14 days compared to placebo on urinary calcium excretion in patients with chronic post-surgical hypoparathyroidism	Day 15

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Ionized calcium	To assess if treatment with Indapamide can affect the level of ionized calcium in the blood during treatment with Indapamide and hereby reduce the need for supplementation with oral calcium and active vitamin D.	Day 15
Sodium diet	assess the efficacy of a low sodium diet in the placebo period on plasma ionized calcium and on the 24-hour urinary calcium excretion in patients with hypoparathyroidism	Day 15
Safety (blood pressure)	To assess the safety (blood pressure) of daily treatment with Indapamide for 14 days compared to placebo	Day 15

Collaborators and Investigators

• Sponsor: Lars Rejnmark

Study record dates

Study Major Dates

• Study Start (Estimated): August 1, 2025
• Primary Completion (Estimated): December 1, 2025
• Study Completion (Estimated): December 1, 2025

Study Registration Dates

• First Submitted: June 15, 2025
• First Submitted That Met QC Criteria: June 15, 2025
• First Posted (Actual): June 24, 2025

Study Record Updates

• Last Update Posted (Actual): August 11, 2025
• Last Update Submitted That Met QC Criteria: August 6, 2025
• Last Verified: August 1, 2025

More Information

Terms related to this study

• Keywords: hypoparathyroidism; hypercalciuria; indapamide
• Additional Relevant MeSH Terms: Endocrine System Diseases; Parathyroid Diseases; Hypoparathyroidism; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Membrane Transport Modulators; Diuretics; Natriuretic Agents; Antihypertensive Agents; Sodium Chloride Symporter Inhibitors; Indapamide
• Other Study ID Numbers: CTIS 2024-516000-41-01; 2024-516000-41-01 (Ctis)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Only IPD used in the results publication
• IPD Sharing Time Frame: start data is time of publication and end 5 years after publication
• IPD Sharing Access Criteria: By contacting the leading author of the publication in order to make a data sharing agreement, which should be signed. Proposal for agreement must contain planned analyses. Statistical analyses have to be approved by independent review before published. Data sharing agreement needs to be approved by the Technology Transfer Office (TTO), Aarhus University Hospital, Denmark
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No