Atarax Syrup, Hyzine-50, Vistaril Intramuscular, Vistacon, Vistaject-25 & -50
Classifications: antihistamine; h1-receptor antagonist; antipruritic; Therapeutic: antihistamine; antipruritic; antianxiety; antiemetic
Pregnancy Category: C
Hydroxyzine HCl: 10 mg, 25 mg, 50 mg tablets; 10 mg/5 mL syrup; 25 mg/5 mL oral suspension; 25 mg/mL, 50 mg/mL injection
Hydroxyzine Pamoate: 25 mg, 50 mg, 100 mg capsules; 25 mg/5 ml suspension
H1-receptor antagonist; effective in treatment of histamine-mediated pruritus or other allergic reactions. Its tranquilizing
effect is produced primarily by depression of hypothalamus and brain-stem reticular formation, rather than cortical areas.
Effective as an antianxiety agent and sedative. Additionally, it is an effective agent for pruritus.
Emotional or psychoneurotic states characterized by anxiety, tension, or psychomotor agitation; to relieve anxiety, control
nausea and emesis, and reduce narcotic requirements before or after surgery or delivery. Also used in management of pruritus
due to allergic conditions (e.g., chronic urticaria), atopic and contact dermatoses, and in treatment of acute and chronic
alcoholism with withdrawal symptoms or delirium tremens.
Known hypersensitivity to hydroxyzine; use as sole treatment in psychoses or depression; pregnancy (category C); lactation.
History of allergies; GI disorders; cardiac disease; COPD; older adults.
Route & Dosage
Adult: PO 25100 mg t.i.d. or q.i.d. IM 25100 mg q46h
Child: PO <6 y, 50 mg/d in divided doses; >6 y, 50 mg/d in divided doses IM 1.1 mg/kg q46h
Adult: PO 25 mg t.i.d. or q.i.d. IM 25 mg q46h
Geriatric: PO 10 mg 34 times daily
Child: PO >6 y, 50100 mg/d in divided doses; <6 y, 50 mg/d in divided doses IM 1.1 mg/kg q46h
Adult: IM 25100 mg q46h
Child: IM 1.1 mg/kg q46h
- Note: Tablets may be crushed and taken with fluid of patient's choice. Capsule may be emptied and contents swallowed with water
or mixed with food. Liquid formulations are available.
- Give deep into body of a relatively large muscle. The Z-track technique of injection is recommended to prevent SC infiltration.
- Recommended site: In adult, the gluteus maximus or vastus lateralis; in children, the vastus lateralis.
- Protect all forms from light. Store at 15°30° C (59°86° F) unless otherwise specified.
INCOMPATIBILITIES Solution/additive: Aminophylline, amobarbital, chloramphenicol, dimenhydrinate, penicillin G, pentobarbital, phenobarbital.
Adverse Effects (≥1%)CNS: Drowsiness
(usually transitory), sedation, dizziness, headache. CV:
Hypotension. GI: Dry mouth. Body as a Whole:
Urticaria, dyspnea, chest tightness, wheezing, involuntary motor activity (rare). Hematologic:
Phlebitis, hemolysis, thrombosis. Skin:
Erythematous macular eruptions, erythema multiforme, digital gangrene from inadvertent IV or intraarterial injection, injection
Diagnostic Test Interference
Possibility of false-positive urinary 17-hydroxycorticosteroid determinations (modified Glenn-Nelson technique).
and cns depressants
add to cns
depression; tricyclic antidepressants
and other anticholinergics
have additive anticholinergic effects; may inhibit pressor effects of epinephrine.
Readily from GI tract. Onset:
1530 min PO. Duration:
46 h. Distribution:
Not known if it crosses placenta or is distributed into breast milk. Metabolism:
In liver. Elimination:
Assessment & Drug Effects
- Evaluate alertness. Drowsiness may occur and usually disappears with continued therapy or following reduction of dosage.
- Monitor condition of oral membranes daily when patient is on high dosage of hydroxyzine.
- Reevaluate usefulness of drug periodically.
- Reduce dosage of the depressant up to 50% when CNS depressants are prescribed concomitantly.
Patient & Family Education
- Do not drive or engage in other potentially hazardous activities until response to drug is known.
- Do NOT take alcohol and hydroxyzine at the same time.
- Notify physician immediately if you become pregnant.
- Relieve dry mouth by frequent warm water rinses, increasing fluid intake, and use of a salivary substitute (e.g., Moi-Stir,
- Give teeth scrupulous care. Avoid irritation or abrasion of gums and other oral tissues.
- Consult physician before self-dosing with OTC medications.