WARNING: INITIATE AND RE-INITIATE IN A HOSPITAL AND MONITOR SERUM SODIUM
SAMSCA should be initiated and re-initiated in patients only in a hospital where serum sodium can be monitored closely.
Too rapid correction of hyponatremia (e.g., >12 mEq/L/24 hours) can cause osmotic demyelination resulting in dysarthria, mutism, dysphagia, lethargy, affective changes, spastic quadriparesis, seizures, coma and death. In susceptible patients, including those with severe malnutrition, alcoholism or advanced liver disease, slower rates of correction may be advisable.
Tolvaptan is a selective vasopressin V2-receptor antagonist with an affinity for the V2-receptor that is 1.8 times that of native arginine vasopressin (AVP).
SAMSCA® is indicated for the treatment of clinically significant hypervolemic and euvolemic hyponatremia (serum sodium <125 mEq/L or less marked hyponatremia that is symptomatic and has resisted correction with fluid restriction), including patients with heart failure, cirrhosis, and Syndrome of Inappropriate Antidiuretic Hormone (SIADH).
Patients requiring intervention to raise serum sodium urgently to prevent or to treat serious neurological symptoms should not be treated with SAMSCA.
It has not been established that raising serum sodium with SAMSCA provides a symptomatic benefit to patients.
Published Studies Related to Samsca (Tolvaptan)
Relationship between clinical trial site enrollment with participant
characteristics, protocol completion, and outcomes: insights from the EVEREST
(Efficacy of Vasopressin Antagonism in Heart Failure: Outcome Study with
Tolvaptan) trial. 
known... CONCLUSIONS: Baseline characteristics, protocol completion, and outcomes differed
Pharmacokinetics and pharmacodynamics of oral tolvaptan administered in 15- to
60-mg single doses to healthy Korean men. 
Tolvaptan is a selective arginine vasopressin V2-receptor antagonist that is used
as an aquaretic agent...
Phase III clinical pharmacology study of tolvaptan. 
antagonist... CONCLUSION: Tolvaptan exerts diuretic effects and causes body weight loss at the
Efficacy and safety of tolvaptan in heart failure patients with volume overload
despite the standard treatment with conventional diuretics: a phase III,
randomized, double-blind, placebo-controlled study (QUEST study). 
overload in HF patients... CONCLUSION: Tolvaptan reduced volume overload and improved congestive symptoms
Effects of tolvaptan on dyspnoea relief from the EVEREST trials. 
CONCLUSION: Post hoc analysis suggests that tolvaptan modestly improves dyspnoea
Clinical Trials Related to Samsca (Tolvaptan)
Post-Authorisation Safety Study of Samsca (Tolvaptan) Used in Routine Medical Practice [Active, not recruiting]
A Drug Utilisation Survey is performed to monitor and document the drug utilisation patterns
of Samsca in routine medical practice.
A Post-Authorisation Safety Study is performed to collect information on the safety of
Samsca when used in a real-life setting.
Effects of Tolvaptan in Healthy Adults [Recruiting]
Tolvaptan is one of new class of medications approved for treatment of low blood sodium
(hyponatremia). It works by interfering with the effect of the antidiuretic hormone,
vasopressin, thereby increasing urine output and decreasing body water. However, the
magnitude of these effects vary from person to person. Thus, the efficacy of tolvaptan is
less reliable than an infusion of a concentrated salt solution for emergency, short term
treatment of hyponatremia.
This study is designed to test 3 hypotheses about the variable efficacy of tolvaptan.
1. The variable effect on urine output is due to individual differences in blood
vasopressin which counteracts the effects of tolvaptan.
2. The differences in blood vasopressin are due to individual differences in the amount
secreted in response to a rise in blood sodium.
3. The variable effect on blood sodium is due mainly to the variable effect on urine
output and can be corrected by maintaining water intake below urine output.
The study has 2 parts and will be performed in 12 healthy adult males.
1. Six subjects will receive tolvaptan at a dose of 60 mg by mouth and six subjects will
receive tolvaptan at 30 mg by mouth. Blood and urine will be collected hourly for 6
hours and water will be ingested in prescribed amounts. For the next 16 hours, subjects
will drink at will and blood and urine will be collected 4 more times.
2. One week later, the same subjects will receive a concentrated salt solution (3% saline)
by vein for 6 hours. During this time, blood and urine will be collected hourly but
drinking will not be permitted. For the next 4 hours, subjects will be allowed to
drink at will while blood and urine are collected twice more.
The volume, concentration and creatinine content of each urine will be determined. Blood
will be analyzed for sodium, vasopressin and, in the first study, tolvaptan.
A PK Study of 3 Dosages of Tolvaptan in Patients With Syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH) [Completed]
This is a study to evaluate how the body handles and metabolizes (PK) the various doses of
the drug Tolvaptan, and what the effect (PD) of the various doses of Tolvaptan are on the
content of "salt" in blood and urine
Effects of Tolvaptan vs Fluid Restriction in Hospitalized Subjects With Dilutional Hyponatremia [Terminated]
The purpose of this study is to determine if hospitalized patients with symptomatic
hyponatremia treated with tolvaptan are in the hospital for less time than patients treated
with fluid restriction. The study will also test if tolvaptan is better than fluid
restriction in treating the symptoms of hyponatremia in hospitalized patients.
Effect of the Aquaretic Tolvaptan on Nitric Oxide System. A Dose-response Study (DOVA) [Active, not recruiting]
Tolvaptan is a selective vasopressin receptor antagonist (V2R) that increases free water and
sodium excretion. Inhibition of V2R increases vasopressin concentration in plasma, which
stimulates V1-receptors in the vascular bed and may change both central and brachial
hemodynamics and plasma concentration of vasoactive hormones.
The purpose of the study is to measure the effects of tolvaptan on renal handling of water
and sodium, systemic hemodynamics and vasoactive hormones at baseline and during nitric
oxide (NO)-inhibition with L-NG-monomethyl-arginine (L-NMMA).
Reports of Suspected Samsca (Tolvaptan) Side Effects
Blood Urea Increased (50),
Condition Aggravated (46),
Rapid Correction of Hyponatraemia (38),
Cardiac Failure (34),
Wrong Technique in Drug Usage Process (33),
Renal Impairment (26),
Dehydration (24), more >>
Page last updated: 2014-12-01