The Navigation Model of Therapy: Why Awareness Changes Everything
November 16, 2025
Brand Name :
Samsca, Jynarque
Synonyms :
tolvaptan
Class :
Vasopressin Antagonists; Vasopressin-Related
Dosage Forms & StrengthsÂ
tablet (Samsca)Â
30mgÂ
15mgÂ
tablet (Jynarque)Â
90mgÂ
60mgÂ
45mgÂ
30mgÂ
15mgÂ
Safety and efficacy not establishedÂ
Refer to the adult dosing regimenÂ
may enhance the serum concentration when combined with tolvaptan
may enhance the serum concentration when combined with tolvaptan
may enhance the serum concentration when combined with tolvaptan
may enhance the serum concentration when combined with tolvaptan
may enhance the serum concentration when combined with tolvaptan
tolvaptan: they may enhance the serum concentration of CYP3A Inhibitors
tolvaptan: they may enhance the serum concentration of CYP3A Inhibitors
tolvaptan: they may enhance the serum concentration of CYP3A Inhibitors
tolvaptan: they may enhance the serum concentration of CYP3A Inhibitors
tolvaptan: they may enhance the serum concentration of CYP3A Inhibitors
may diminish the serum concentration when combined with tolvaptan
may diminish the serum concentration when combined with tolvaptan
may diminish the serum concentration when combined with tolvaptan
may diminish the serum concentration when combined with tolvaptan
may diminish the serum concentration when combined with tolvaptan
may decrease the therapeutic effect when combined with desmopressin
may increase the adverse effect when combined with tolvaptan
It may enhance the effect when combined with grapefruit by CYP3A4 metabolism
It may diminish the effect when combined with griseofulvin by CYP3A4 metabolism
It may enhance the effect when combined with miconazole vaginal by affecting CYP3A4 metabolism
CYP3A strong enhancers of the small intestine may reduce the bioavailability of tolvaptan
may enhance the serum concentration of CYP3A4 inhibitors
sodium chloride increases the toxicity of tolvaptan
may increase the hyperkalemic effect when combined with angiotensin II receptor blockers
may increase the hyperkalemic effect when combined with angiotensin II receptor blockers
may increase the hyperkalemic effect when combined with angiotensin II receptor blockers
may increase the hyperkalemic effect when combined with angiotensin II receptor blockers
may increase the hyperkalemic effect when combined with angiotensin II receptor blockers
may increase the hyperkalemic effect when combined with ace inhibitors
may increase the hyperkalemic effect when combined with ace inhibitors
may increase the hyperkalemic effect when combined with ace inhibitors
may increase the hyperkalemic effect when combined with ace inhibitors
may increase the hyperkalemic effect when combined with ace inhibitors
may diminish the serum concentration when combined with tolvaptan
may diminish the serum concentration when combined with tolvaptan
may enhance the serum concentration when combined with digoxin
spironolactone and hydrochlorothiazide
may increase the hyperkalemic effect when combined with potassium-sparing diuretics
may increase the hyperkalemic effect when combined with potassium-sparing diuretics
may increase the hyperkalemic effect when combined with potassium-sparing diuretics
may increase the hyperkalemic effect when combined with potassium-sparing diuretics
may increase the hyperkalemic effect when combined with potassium-sparing diuretics
It may enhance the metabolism when combined with dexamethasone
may enhance the hyperkalemic effect
may enhance the hyperkalemic effect
may enhance the hyperkalemic effect
may enhance the hyperkalemic effect
may enhance the hyperkalemic effect
may enhance the hyperkalemic effect
may enhance the hyperkalemic effect
may enhance the hyperkalemic effect
may enhance the hyperkalemic effect
may enhance the hyperkalemic effect
spironolactone and hydrochlorothiazide
may enhance the hyperkalemic effect
may enhance the hyperkalemic effect
may enhance the hyperkalemic effect
may enhance the hyperkalemic effect
may enhance the hyperkalemic effect
when both drugs are combined, there may be a high metabolism of tolvaptan 
the effect of tolvaptan is decreased by lorlatinib, by altering intestinal or hepatic CYP3A4 enzyme metabolism
it enhances the serum potassium levels
it may enhance the serum potassium levels
may decrease the serum concentration
may decrease the serum concentration
may decrease the serum concentration
may decrease the serum concentration
may decrease the serum concentration
may decrease the serum concentration
may decrease the serum concentration
may decrease the serum concentration
may decrease the serum concentration
may increase the serum concentration
may increase the serum concentration
may increase the serum concentration
may increase the serum concentration
may increase the serum concentration
may increase the serum concentration
may increase the serum concentration
may increase the serum concentration
may increase the serum concentration
may increase the serum concentration
may increase the serum concentration
may increase the serum concentration
may increase the serum concentration
may increase the serum concentration
may increase the serum concentration
the efficacy of phosphoric acid may be decreased due to an increase in rate of excretion
Actions and spectrum:Â
The actions of tolvaptan include:Â
The spectrum of tolvaptan includes:Â
Frequency definedÂ
>10%Â
SamscaÂ
JynarqueÂ
1-10%Â
SamscaÂ
JynarqueÂ
Post marketing ReportsÂ
Investigations: HypernatremiaÂ
Hepatobiliary disorders: Liver failure  Â
Neurologic: Osmotic demyelination syndromeÂ
Immune system disorders: anaphylactic shock and rashÂ
Black Box Warning:Â
tolvaptan has a black box warning, which is the most serious warning issued by the US Food and Drug Administration (FDA). The black box warning for tolvaptan is related to the risk of liver injury and failure.Â
The warning states that tolvaptan can cause potentially fatal liver injury, including hepatic failure requiring liver transplantation. The risk is highest in patients with underlying liver disease, but it can occur in patients without pre-existing liver disease as well.Â
Contraindication/Caution:Â
Contraindication:Â
Caution:Â
Comorbidities:Â
Pregnancy consideration: pregnancy category: not assignedÂ
Lactation: It is not known whether tolvaptan is excreted in human milk. Â
Pregnancy category:Â
Pharmacology:Â
tolvaptan is a selective vasopressin V2 receptor antagonist, which means that it blocks the action of the hormone vasopressin on the V2 receptors in the kidneys. Vasopressin regulates the body’s water balance by increasing water reabsorption in the kidneys. By blocking the action of vasopressin on the V2 receptors, tolvaptan promotes water excretion and increases urine output, leading to an increase in serum sodium levels.Â
tolvaptan is rapidly absorbed after oral administration, with peak plasma concentrations reached within 2-4 hours. The drug is metabolized by liver, primarily by the enzyme CYP3A4, and is eliminated mainly via the feces. tolvaptan has a half-life of about 12-15 hours in healthy individuals, but this may be prolonged in patients with liver or kidney impairment.Â
tolvaptan is primarily used for the treatment of hyponatremia, which is a condition characterized by low sodium levels in the blood. Hyponatremia can be caused by a variety of underlying conditions, such as heart failure, liver cirrhosis. tolvaptan can be effective in increasing serum sodium levels and improving symptoms in patients with hyponatremia, although it is associated with a risk of liver injury and should be used with caution in patients with liver impairment. Â
Pharmacodynamics:Â
tolvaptan is a selective vasopressin V2 receptor antagonist that works by blocking the action of arginine vasopressin (AVP), a hormone that regulates the balance of water and electrolytes in the body. By blocking the AVP receptors in the renal collecting ducts, tolvaptan increases water excretion and decreases the concentration of electrolytes such as sodium in the urine.Â
The pharmacodynamics of tolvaptan are primarily related to its effect on the renal system. tolvaptan works by inhibiting the reabsorption of water in the kidney, leading to an increase in urine output and a decrease in plasma sodium concentration. This effect is dose-dependent and can be observed within hours of administration.Â
In patients with hyponatremia (low sodium levels in the blood), tolvaptan has been shown to increase serum sodium levels by promoting the excretion of excess water.  Â
Pharmacokinetics:Â
AbsorptionÂ
tolvaptan is rapidly absorbed after oral administration, with peak plasma concentrations reached within 2 to 4 hours. Food can delay the absorption of tolvaptan but does not significantly affect its bioavailability.Â
DistributionÂ
tolvaptan is highly protein-bound (99%) and has a large volume of distribution, indicating that it is extensively distributed throughout the body.Â
MetabolismÂ
tolvaptan is extensively metabolized by cytochrome P450 (CYP) enzymes, primarily CYP3A4 and CYP2C9. The major metabolites of tolvaptan are the 1-O-glucuronide and the 6-hydroxymethyl metabolites, both of which are pharmacologically inactive.Â
Elimination and excretionÂ
tolvaptan is primarily eliminated by renal excretion, with about 70% of a dose excreted unchanged in the urine. The remainder of the dose is eliminated in the feces (21%) and through metabolism (9%).Â
Administration:Â
Patient information leafletÂ
Generic Name: tolvaptanÂ
Pronounced: [ tol-VAP-tan]Â Â Â
Why do we use tolvaptan?Â