None listed
Conditions
Brief summary
The determination of a specific diagnosis in patients with polyuria syndromes is a frequent problem in clinical practice. Determining the correct diagnosis is crucial to optimising the management of these conditions as treatment approaches differ, and both inadequate and incorrect treatment can cause severe complications. However, differentiating these conditions, particularly arginine vasopressin deficiency (AVP-D) and primary polydipsia has proven very difficult and complex stimulation testing is needed for the diagnosis of AVP-D and primary polydipsia. This study will look at the response of the body's pituitary gland to a single dose of a medication called tolvaptan compared to placebo to see if this could be used as a new and simpler test for the diagnosis of these conditions.
Interventions
This study will look at the response of the pituitary gland to a single dose of tolvaptan 30 mg oral capsule compared with placebo oral capsule. Administration will be supervised.
This is a crossover study where participants will attend for two study visits and receive the active treatment (tolvaptan 30 mg) on one study visit day and placebo on the other study visit day. The wash-out period between treatments is a minimum of 3 days.
Sponsors
Princess Alexandra Hospital, Metro South Health Service
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Diagnosis
Masking
Blinded (masking used) (Subject, Caregiver)
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
Healthy participants o Age >18 years o Healthy participant with no significant comorbidities Participants with arginine vasopressin deficiency or primary polydipsia - 18 years or older - BMI 18.5 to 30 kg/m2 - polyuria >3L/day or >50mL/kg body weight/day or regular desmopressin administration.
Exclusion criteria
Healthy volunteers o BMI <18.5 kg/m2 or >30 kg/m2 o Vigorous physical exercise within 24 hours of study participation o Alcohol intake or cigarette smoking within 24 hours of study participation o Pregnancy and breastfeeding o Evidence of disordered drinking habits (polyuria >50 mL/kg body weight and polydipsia >3L/24 hours) o Acute illness o Electrolyte abnormalities including hyponatraemia or other electrolyte disorders o Significant medical comorbidities (cardiac, hepatic and kidney failure, diabetes mellitus, pituitary or adrenal disorders, untreated hypothyroidism, uncontrolled hypertension and epilepsy) o Concomitant medications with the potential to interfere with the results (including those known to cause electrolyte disturbances and/or solute diuresis such as diuretics, glucocorticoids, anti-epileptic, anti-depressant and anti-emetic medications). Participants with arginine vasopressin deficiency or primary polydipsia o Vigorous exercise <24 hours before study participation o Alcohol intake or cigarette smoking <24 hours before the study participation, pregnancy or breastfeeding o Aacute illness. o Significant medical comorbidities (cardiac, hepatic and kidney failure, diabetes mellitus, pituitary or adrenal disorders, untreated hypothyroidism, uncontrolled hypertension and epilepsy) o Concomitant medications with the potential to interfere with the results (including those known to cause electrolyte disturbances and/or solute diuresis such as diuretics, glucocorticoids, anti-epileptic, anti-depressant and anti-emetic medications).
Outcome results
None listed