Determinants of thiazide induced hyponatraemia in pre-exposed elderly–a controlled experiment

Conditions: hyponatraemia, elderly, sodium level, Thiazide dutch: hyponatremie, ouderen, natrium, thiazide

Registration Number: NL-OMON28630

Lead Sponsor: Bert-Jan van den BornAcademic Medical CentreDept. Vascular MedicineMeibergdreef 9 F4-255the Netherlandstel:+31 20 5665956

Brief Summary: Not available

Detailed Description: Not available

Recruitment & Eligibility

Status: Pending

Sex: Not specified

Target Recruitment: 36

Inclusion Criteria

1. Age 60-80 years;
2. Previously admitted with thiazide-induced hyponatraemia;
3. Patients must be willing and medically able to discontinue anti-hypertensive therapy six weeks before the study and for the duration of the study;
4. Patients must be willing to be admitted for 24 hours and must be medically able to take the study medication;
5. Patients must be willing to give informed consent.

Exclusion Criteria

1. Other causes for hyponatraemia (e.g. heart failure, pulmonary disease, medication associated with hyponatraemia);
2. Renal dysfunction (estimated clearance <50 ml/min according to Cockroft-Gault);
3. Liver cirrhosis;
4. Heartfailure;
5. Medication: antipressiva (SSRI’s), antiepileptica, prednisone, NSAID’s, opioids, other diuretics (e.g. lasix, burinex, chloorthalidon, dytac);
6. Allergy for sulfonamidederivaten;
7. Therapy resistant hypertension (BP>140/90 mmHg while using 3 or more anti-hypertensive drugs)

Study & Design

Study Type: Interventional

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Effect of a single oral dose hydrochloorthiazide 50 mg intake on the serum and urine sodium, serum ADH, prostaglandin E2 and urinary aquaporin-2 excretion in elderly patients (aged 60-80 years) with previous thiazide-induced hyponatraemia (sodium <125 mmol/l) without another cause for their hyponatraemia and matched controls receiving a thiazide diuretic without hyponatraemia.<br>Urinary hydrochlorothiazide concentrations are measured to analyse differences in thiazide metabolism. The response to ADH will be assessed by expression of AVPR2 in a cell-culture and determine its activity by measurement of cAMP<br>

Secondary Outcome Measures