Hydroxyzine Pamoate

**Semantic type:** Pharmacologic Substance

**Definition:** The pamoate salt form of hydroxyzine, a synthetic piperazine histamine H1-receptor antagonist with anti-allergic, antispasmodic, sedative, anti-emetic and anti-anxiety properties. Hydroxyzine pamoate blocks the H1 histamine receptor and prevents the symptoms that are caused by histamine activity on capillaries, bronchial smooth muscle, and gastrointestinal smooth muscle, including vasodilatation, increased capillary permeability, bronchoconstriction, and spasmodic contraction of gastrointestinal smooth muscle. In addition, hydroxyzine pamoate crosses the blood-brain barrier and acts on the histamine H1-receptors in the central nervous system. (NCI05)

**Synonyms:** - 2-(2-(4-(p-Chloro-alpha-phenylbenzyl)-1-piperazinyl)ethoxy)ethanol 4,4'-methylenebis(3-hydroxy-2-naphthoate) (1:1) - Atarax P - Ethanol, 2-(2-(4-((4-chlorophenyl)phenylmethyl)-1-piperazinyl)ethoxy)-, compound with 4,4'-Methylenebis(3-hydroxy-2-naphthalenecarboxylic Acid)(1:1) - HYDROXYZINE PAMOATE - Masmoran - Paxistil - Vistaril