An aquaretic is a novel class of drug that is used to promote aquaresis, the excretion of water without

electrolyte An electrolyte is a medium containing ions that is electrically conducting through the movement of those ions, but not conducting electrons. This includes most soluble salts, acids, and bases dissolved in a polar solvent, such as water. Upon dis ...

loss. Strictly speaking, aquaretics are not

diuretic A diuretic () is any substance that promotes diuresis, the increased production of urine. This includes forced diuresis. A diuretic tablet is sometimes colloquially called a water tablet. There are several categories of diuretics. All diuretics in ...

s but are sometimes classified as such. Aquaresis is preferable to

diuresis Diuresis () is increased urination (polyuria) or, in the related word senses more often intended, the physiological process that produces such an increase or the administration of medications to encourage that process. It involves extra urine pro ...

in the treatment of hyponatremia.

Pharmacokinetics

Aquaretics increase urine output without increasing

sodium Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable iso ...

and

chloride The chloride ion is the anion (negatively charged ion) Cl−. It is formed when the element chlorine (a halogen) gains an electron or when a compound such as hydrogen chloride is dissolved in water or other polar solvents. Chloride salts ...

excretion, thus causing an increase in urine whilst retaining electrolytes.

Examples

A number of herbal medicines are classified as aquaretics, for example

common horsetail ''Equisetum arvense'', the field horsetail or common horsetail, is an herbaceous perennial plant in the Equisetidae (horsetails) sub-class, native throughout the arctic and temperate regions of the Northern Hemisphere. It has separate sterile n ...

common nettle ''Urtica dioica'', often known as common nettle, burn nettle, stinging nettle (although not all plants of this species sting) or nettle leaf, or just a nettle or stinger, is a herbaceous perennial flowering plant in the family Urticaceae. Or ...

leaves. Synthetic aquaretics are

vasopressin receptor antagonist A vasopressin receptor antagonist (VRA) is an agent that interferes with action at the vasopressin receptors. Most commonly VRAs are used in the treatment of hyponatremia, especially in patients with congestive heart failure, liver cirrhosis or SIAD ...

s and include

conivaptan Conivaptan, sold under the brand name Vaprisol, is a non-peptide inhibitor of the receptor for anti-diuretic hormone, also called vasopressin. It was approved in 2004 for hyponatremia (low blood sodium levels). The compound was discovered by As ...

tolvaptan Tolvaptan, sold under the brand name Samsca among others, is an aquaretic drug that functions as a selective, competitive vasopressin receptor 2 (V2) antagonist used to treat hyponatremia (low blood sodium levels) associated with congestive hea ...

demeclocycline Demeclocycline (International Nonproprietary Name, INN, British Approved Name, BAN, United States Adopted Name, USAN, brand name Declomycin) is a tetracycline antibiotic which was derived from a mutant strain of ''Streptomyces aureofaciens''. Use ...

, and

mozavaptan Mozavaptan (INN) is a vasopressin receptor antagonist marketed by Otsuka. In Japan, it was approved in October 2006 for hyponatremia (low blood sodium Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomi ...

(OPC-31260), as well as

lithium Lithium (from el, λίθος, lithos, lit=stone) is a chemical element with the symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard conditions, it is the least dense metal and the least dense solid el ...

. Conivaptan hydrochloride and tolvaptan have been approved by the FDA for treating

syndrome of inappropriate antidiuretic hormone Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is characterized by excessive unsuppressible release of antidiuretic hormone (ADH) either from the posterior pituitary gland, or an abnormal non-pituitary source. Unsuppressed ADH c ...

. Mozavaptan is approved in Japan.

References

Diuretics {{antihypertensive-stub