Brands, Medical Use, Clinical Data
Drug Category
- Antipruritics
- Histamine H1 Antagonists
- Anxiolytics sedatives and hypnotics
Dosage Forms
- Capsule
- Liquid
- Solution
- Syrup
Brands / Synonyms
Alamon; Atara; Atarax; Atarax Base; Ataraxoid; Atarazoid; Atarox; Atazina; Aterax; Deinait; Durrax; Equipoise; Equipose; Fenarol; Hidroxizina [Inn-Spanish]; Hy-Pam 25; Hychotine; Hydoxyzine; Hydroksyzyny; Hydroksyzyny [Polish]; Hydroxine; Hydroxizine; Hydroxizinum; Hydroxycine; Hydroxyzin; Hydroxyzine; Hydroxyzine Base; Hydroxyzine Hcl; Hydroxyzine Pamoate; Hydroxyzinum [Inn-Latin]; Hydroxyzyne; Idrossizina; Idrossizina [Dcit]; Masmoran; Neo-Calma; Neurozina; Nevrolaks; Orgatrax; Pamazone; Parenteral; Paxistil; Placidol; Plaxidol; Quiess; Tran-Q; Tranquizine; Traquizine; Vesparaz-Wirkstoff; Vistaril; Vistaril Pamoate; Vistazine
Indications
For symptomatic relief of anxiety and tension associated with psychoneurosis and as an adjunct in organic disease states in which anxiety is manifested. Useful in the management of pruritus due to allergic conditions such as chronic urticaria.
Pharmacology
Hydroxyzine, a piperazine antihistamine structurally related to buclizine, cyclizine, and meclizine, is used to treat histamine-mediated pruritus or pruritus due to allergy, nausea and vomiting, and, in combination with an opiate agonist, anxiolytic pain. Hydroxyzine is also used as a perioperative sedative and anxiolytic and to manage acute alcohol withdrawal. Hydroxyzine's active metabolite, cetirizine, is also used as an H1-antagonist.
Mechanism of Action
Hydroxyzine competes with histamine for binding at H1-receptor sites on the effector cell surface, resulting in suppression of histaminic edema, flare, and pruritus. The sedative properties of hydroxyzine occur at the subcortical level of the CNS. Secondary to its central anticholinergic actions, hydroxyzine may be effective as an antiemetic.
Absorption
Rapidly absorbed from the gastrointestinal tract
Toxicity
Oral, rat LD50: 950 mg/kg. Symptoms of overexposure include hypersedation.
Biotrnasformation / Drug Metabolism
Hepatic
Contraindications
Hydroxyzine, when administered to the pregnant mouse, rat, and rabbit, induced fetal abnormalities in the rat and
mouse at doses substantially above the human therapeutic range. Clinical data in human beings are inadequate to
establish safety in early pregnancy. Until such data are available, hydroxyine is contraindicated in early
pregnancy.
Hydroxyzine is contraindicated for patients who have shown a previous hypersensitivity to it.
Drug Interactions
THE POTENTIATING ACTION OF HYDROXYZINE MUST BE CONSIDERED WHEN THE DRUG IS USED IN CONJUNCTION WITH CENTRAL
NERVOUS SYSTEM DEPRESSANTS SUCH AS NARCOTICS, NON-NARCOTIC ANALGESICS AND BARBITURATES. Therefore when central
nervous system depressants are administered concomitantly with hydroxyzine their dosage should be reduced.
Since drowsiness may occur with use of this drug, patients should be warned of this possibility and cautioned
against driving a car or operating dangerous machinery while taking Atarax. Patients should be advised against the
simultaneous use of other CNS depressant drugs, and cautioned that the effect of alcohol may be increased.
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