A Prospective Randomised Control Trial To Study Efficacy And Safety Of Thiazide Diuretic In Subjects With Idiopathic Hypoparathyroidism

Protocol for Maintaining Serum Calcium Levels (8-8.5 mg/dl) Pre-Study Preparation 1. Inclusion Criteria Fulfillment    - Assess patients to ensure they meet the inclusion criteria for the study. 2. Active Vitamin D Dosage Adjustment    - Titrate the dose of Active Vitamin D by 0.25 µg/day to maintain serum calcium levels between 8.0 and 8.5 mg/dl.    - Maximum dose: 3 µg/day. 3. Monitoring    - Follow up with patients weekly to measure serum calcium (S. Ca) and phosphorus levels until the target calcium range is achieved.    - Once patients achieve target serum calcium levels, they can be directly recruited for the study. 4. Dietary Assessment    - Evaluate patients’ daily intake of calcium and phosphorus using a semi-quantitative food frequency questionnaire administered by a trained dietitian. Study Enrollment and Initial Phase 5. Enrollment    - Enroll all subjects who fulfill the inclusion criteria. 6. Medication Continuation    - Instruct subjects to continue their usual medications along with calcium supplementation. 7. Dose Adjustment Period (Two Weeks)    - Adjust the dose of Active Vitamin D as needed to maintain serum calcium levels between 8.0 and 8.5 mg/dl.  Control Period 8. Diet Control Period (4-5 days)    - Provide all participants with a diet of constant calcium (600-1300 mg) and sodium (100-200 meq). 9. Baseline Measurements    - Record baseline vitals and conduct investigations as outlined in Annexure 1 for each study subject. Randomization and Experimental Phase 10. Randomization     - Randomize participants into two groups (A and B) in a 1:1 ratio. 11. Experimental Intervention - Part 1     - Group A: Administer hydrochlorothiazide (HCTZ) 12.5 mg with a low-salt diet (50-100 meq/day).     - Group B: Administer placebo. 12. Day 4 Post-Intervention     - Measure the following parameters in both groups:       - Vitals: Blood Pressure (BP), Heart Rate (HR)       - Body weight, estimated Glomerular Filtration Rate (eGFR)       - Serum: Calcium, phosphorus, sodium, potassium, albumin, intact parathyroid hormone (iPTH), Vitamin D       - 24-hour urinary excretion: calcium, sodium, phosphorus, and fractional urinary calcium excretion. 13. Dose Adjustment     - If no contraindications, increase HCTZ dose to 25 mg from 12.5 mg on Day 4. 14. Day 7 Measurements     - Repeat all parameters measured on Day 4. Washout Period 15. Intervention-Free Period     - Allow a washout period of 2 weeks where participants are free of any intervention. Experimental Phase - Part 2 (Crossover) 16. Crossover Intervention     - Group A: Switch to placebo.     - Group B Switch to HCTZ (12.5 mg) with a low-salt diet. 17. Day 4 Post-Intervention     - Measure the same parameters as in the first part. 18. Dose Adjustment     - Increase HCTZ dose to 25 mg from 12.5 mg on Day 4 if no contraindications. 19. Day 7 Measurements     - Repeat all parameters measured on Day 4. Extension Phase 20.Continuation with Experimental Drug     - Administer the experimental drug (HCTZ) to all participants at a dose of 12.5 mg or 25 mg as tolerated. 21. Follow-Up     - Monitor participants for 1 month for primary and secondary outcomes. 22. Outcome Assessment     - Conduct a final assessment of outcomes at the end of the study. This protocol outlines a comprehensive approach to maintaining serum calcium levels within the target range and monitoring the effects of hydrochlorothiazide with a low-salt diet.