Vaprisol: A Unique Mechanism of Action (MOA)
Vaprisol is different from other treatments for hyponatremia because it targets the neurohormone arginine vasopressin (AVP), the key regulator of salt and water balance in the body.1,2 By blocking AVP receptors in the kidneys, Vaprisol promotes aquaresis—defined as an increase in free water excretion without the loss of electrolytes.1,3 Aquaresis is best measured by the increase in effective water clearance (EWC).4 It is typically accompanied by an increase in urine output and a reduction in urine osmolality, resulting in a net loss of water from the body.4 Aquaresis is distinguished from diuresis caused by loop diuretic agents in that electrolyte excretion is spared during aquaresis.3 Loop diuretics typically cause diuresis, resulting in excretion of electrolytes in the urine.3
The animation below will help you visualize the Vaprisol MOA.
References: 1. Vaprisol Prescribing Information. Astellas Pharma US, Inc. 2. Verbalis JG. Disorders of body water homeostasis. Best Pract Res Clin Endocrinol Metab. 2003;17:471-503. 3. Goldsmith SR. Current treatments and novel pharmacologic treatments for hyponatremia in congestive heart failure. Am J Cardiol. 2005;95(suppl):14B-23B. 4. Mallie JP, Bichet DG, Halperin ML. Effective water clearance and tonicity balance: the excretion of water revisited. Clin Invest Med. 1997;20:16-24.
|