Product Information
Registration Status: ActiveSAMSCA TABLET 15MG is approved to be sold in Singapore with effective from 2020-04-24. It is marketed by OTSUKA PHARMACEUTICALS (SINGAPORE) PTE LTD, with the registration number of SIN15934P.
This product contains Tolvaptan 15mg in the form of TABLET. It is approved for ORAL use.
This product is manufactured by Korea Otsuka Pharmaceutical Co. in KOREA, Ltd. in REPUBLIC OF, andOtsuka Pharmaceutical Co. in JAPAN.
It is a Prescription Only Medicine that can only be obtained from a doctor or a dentist, or a pharmacist with a prescription from a Singapore-registered doctor or dentist.
Description
Tolvaptan is used to treat low blood sodium levels (hyponatremia) associated with various conditions like congestive heart failure, cirrhosis, and syndrome of inappropriate antidiuretic hormones (SIADH). FDA approved on May 19, 2009.
Indication
Treatment of symptomatic and resistant to fluid restriction euvolemic or hypervolemic hyponatremia associated with congestive heart failure, SIADH, and cirrhosis.
Mechanism of Action
Tolvaptan is a selective and competitive arginine vasopressin receptor 2 antagonist. Vasopressin acts on the V2 receptors found in the walls of the vasculature and luminal membranes of renal collecting ducts. By blocking V2 receptors in the renal collecting ducts, aquaporins do not insert themselves into the walls thus preventing water absorption. This action ultimately results in an increase in urine volume, decrease urine osmolality, and increase electrolyte-free water clearance to reduce intravascular volume and an increase serum sodium levels. Tolvaptan is especially useful for heart failure patients as they have higher serum levels of vasopressin.
Pharmacokinetics
- Absorption
- Tmax, Healthy subjects: 2 - 4 hours; Cmax, Healthy subjects, 30 mg: 374 ng/mL; Cmax, Healthy subjects, 90 mg: 418 ng/mL; Cmax, heart failure patients, 30 mg: 460 ng/mL; Cmax, heart failure patients, 90 mg: 723 ng/mL; AUC(0-24 hours), 60 mg: 3.71 μg·h/mL; AUC(∞), 60 mg: 4.55 μg·h/mL; The pharmacokinetic properties of tolvaptan are stereospecific, with a steady-state ratio of the S-(-) to the R-(+) enantiomer of about 3. The absolute bioavailability of tolvaptan is unknown. At least 40% of the dose is absorbed as tolvaptan or metabolites. Food does not impact the bioavailability of tolvaptan.
- Distribution
- Healthy subjects: 3L/kg; slightly higher in heart failure patients.
- Metabolism
- Metabolism exclusively by CYP3A4 enzyme in the liver. Metabolites are inactive.
- Elimination
Clearance
4 mL/min/kg (post-oral dosing).
Toxicity
The oral LD50 of tolvaptan in rats and dogs is >2000 mg/kg. Most common adverse reactions (≥5% placebo) are thirst, dry mouth, asthenia, constipation, pollakiuria or polyuria, and hyperglycemia.
Active Ingredient/Synonyms
Tolvaptan | Tolvaptan |
Source of information: Drugbank (External Link). Last updated on: 3rd July 18. *Trade Name used in the content below may not be the same as the HSA-registered product.