Tolvaptan

Brand Names: Jynarque, Jynarque

Drug Class: Vasopressin V2 Receptor Antagonist

Overview

11 DESCRIPTION JYNARQUE contains tolvaptan, a selective vasopressin V2-receptor antagonist in immediate release tablets for oral administration available in 15 mg, 30 mg, 45 mg, 60 mg and 90 mg strengths. Tolvaptan is (±)-4'-[(7-chloro-2,3,4,5-tetrahydro-5-hydroxy-1 H -1-benzazepin-1-yl) carbonyl]- o -tolu- m -toluidide. The empirical formula is C 26 H 25 ClN 2 O 3 . Molecular weight is 448.94.

Mechanism of Action

12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Tolvaptan is a selective vasopressin V 2 -receptor antagonist with an affinity for the V 2 -receptor that is 1.8 times that of native arginine vasopressin (AVP). Tolvaptan affinity for the V 2 -receptor is 29 times that for the V 1a -receptor. Decreased binding of vasopressin to the V 2 -receptor in the kidney lowers adenylate cyclase activity resulting in a decrease in intracellular adenosine 3′, 5′-cyclic monophosphate (cAMP) concentrations. Decreased cAMP concentrations prevent aquaporin 2 containing vesicles from fusing with the plasma membrane, which in turn causes an increase in urine water excretion, an increase in free water clearance (aquaresis) and a decrease in urine osmolality.

Indications

  • 1 INDICATIONS AND USAGE JYNARQUE is indicated to slow kidney function decline in adults at risk of rapidly progressing autosomal dominant polycystic kidney disease (ADPKD). JYNARQUE is a selective vasopressin V 2 -receptor antagonist indicated to slow kidney function decline in adults at risk of rapidly progressing autosomal dominant polycystic kidney disease (ADPKD) ( 1 )

Common Doses

  • 45 mg
  • 60 mg
  • 90 mg
  • 15 mg

Dosage

2 DOSAGE AND ADMINISTRATION Recommended dosage ( 2.1 ) Initial Dosage Titration Step Target Dosage 1st Dose 45 mg 1st Dose 60 mg 1st Dose 90 mg 2nd Dose (8 hours later) 15 mg 2nd Dose (8 hours later) 30 mg 2nd Dose (8 hours later) 30 mg Total Daily Dose 60 mg Total Daily Dose 90 mg Total Daily Dose 120 mg Dose adjustment is recommended for patients taking moderate CYP3A inhibitors ( 2.4 , 5.4 , 7.1 ) 2.1 Recommended Dosage The initial dosage for JYNARQUE is 60 mg orally per day as 45 mg taken on waking and 15 mg taken 8 hours later.

Black Box Warning

WARNING: RISK OF SERIOUS LIVER INJURY JYNARQUE (tolvaptan) can cause serious and potentially fatal liver injury. Acute liver failure requiring liver transplantation has been reported [see Warnings and Precautions (5.1) ] . Measure ALT, AST and bilirubin before initiating treatment, at 2 weeks and 4 weeks after initiation, then monthly for the first 18 months and every 3 months thereafter [see Warnings and Precautions (5.1) ] .

Contraindications

  • 4 CONTRAINDICATIONS JYNARQUE is contraindicated in patients: With a history, signs or symptoms of significant liver impairment or injury. This contraindication does not apply to uncomplicated polycystic liver disease [see Warnings and Precautions (5.1) ] Taking strong CYP3A inhibitors With uncorrected abnormal blood sodium concentrations [see Warnings and Precautions (5.3) ] Unable to sense or respond to thirst [see Warnings and Precautions (5.3) ] Hypovolemia [see Warnings and Precautions (5.3) ] Hypersensitivity (e.g.

Side Effects

  • 6 ADVERSE REACTIONS The following adverse reactions are discussed in more detail in other sections of the labeling: Serious Liver Injury [see Boxed Warning and Warnings and Precautions (5.1) ] Hypernatremia, Dehydration and Hypovolemia [see Warnings and Precautions (5.3) ] Drug Interactions with Inhibitors of CYP3A [see Warnings and Precautions (5.4) ] Most common observed adverse reactions with JYNARQUE (incidence >10% and at least twice that for placebo) were thirst, polyuria, nocturia, pollakiuria and polydipsia ( 6.

Interactions

  • 7 DRUG INTERACTIONS Avoid concomitant use with: Strong CYP3A Inducers ( 7.1 ) V 2 -Receptor Agonists ( 7.2 ) 7.1 CYP3A Inhibitors and Inducers CYP3A Inhibitors Tolvaptan's AUC was 5.4 times as large and Cmax was 3.5 times as large after co-administration of tolvaptan and 200 mg ketoconazole [see Warnings and Precautions (5.4) and Clinical Pharmacology (12.3) ] . Larger doses of the strong CYP3A inhibitor would be expected to produce larger increases in tolvaptan exposure. Concomitant use of tolvaptan with strong CYP3A inhibitors is contraindicated [see Contraindications (4) ].