hydroxyzine

Therapeutic Classification: antianxiety agents, sedative/hypnotics

Pharmacologic Classification: antihistamines

Indications ⬆ ⬇

BEERS REMS

Anxiety.
Preoperative sedation.
Nausea and vomiting.
Pruritus.
Urticaria

Action ⬆ ⬇

Acts as a CNS depressant at the subcortical level of the CNS.
Has anticholinergic, antihistaminic, and antiemetic properties.
Blocks histamine 1 receptors.

Therapeutic effects:

Sedation.
Relief of anxiety.
Decreased nausea and vomiting.
Decreased allergic symptoms associated with release of histamine, including pruritus and urticaria.

Pharmacokinetics ⬆ ⬇

Absorption: Well absorbed following oral and intramuscular administration.

Distribution: Unknown.

Metabolism/Excretion: Completely metabolized by the liver; eliminated in the feces via biliary excretion.

Half-Life: 3 hr.

Time/Action Profile ⬆ ⬇

(sedative, antiemetic, antipruritic effects)

ROUTE	ONSET	PEAK	DURATION
PO	15–30 min	2–4 hr	4–6 hr
IM	15–30 min	2–4 hr	4–6 hr

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity;
QT interval prolongation;
OB: Pregnancy;
Lactation: Lactation.

Use Cautiously in:

Severe hepatic impairment;
Congenital long QT syndrome, family history of long QT syndrome, recent MI, HF, hypokalemia, hypomagnesemia, bradycardia, or concurrent use of antiarrhythmics;
Pedi: Injection contains benzyl alcohol, which can cause potentially fatal gasping syndrome in neonates;
Geri: Appears on Beers list. risk of anticholinergic adverse reactions in older adults, including falls, delirium, and dementia. Avoid use in older adults.

Adv. Reactions/Side Effects ⬆ ⬇

CV: QT interval prolongation, TORSADES DE POINTES

Derm: acute generalized exanthematous pustulosis, flushing, rash

GI: dry mouth, bitter taste, constipation, nausea

GU: urinary retention

Local: pain (at IM site), abscesses at IM sites

Neuro: drowsiness, agitation, ataxia, dizziness, headache, weakness

Resp: wheezing

Interactions ⬆ ⬇

Drug-drug:

Additive CNS depression with other CNS depressants, including alcohol, antidepressants, antihistamines, opioid analgesics, and sedative/hypnotics.
Concurrent use of QT interval prolonging medications, including amiodarone, azithromycin, chlorpromazine, citalopram, clarithromycin, clozapine, dofetilide, droperidol, erythromycin, fluoxetine, iloperidone, methadone, moxifloxacin, ondansetron, pentamidine, procainamide, quetiapine, quinidine, sotalol, or ziprasidone may ↑ risk of QT interval prolongation and torsades de pointes.
Additive anticholinergic effects with other drugs possessing anticholinergic properties, including antihistamines, antidepressants, atropine, haloperidol, phenothiazines, quinidine, and disopyramide.
Can antagonize the vasopressor effects of epinephrine.

Drug-Natural Products:

Concomitant use of kava-kava, valerian, or chamomile can ↑ CNS depression.
↑anticholinergic effects with angel’s trumpet, jimson weed, and scopolia.

Route/Dosage ⬆ ⬇

PO (Adults ): Antianxiety: 25–100 mg 4 times/day, not to exceed 600 mg/day. Preoperative sedation: 50–100 mg single dose. Antipruritic: 25 mg 3–4 times daily.
PO (Children ): 2 mg/kg/day divided every 6–8 hr.
IM (Adults ): Preoperative sedation: 25–100 mg single dose. Antiemetic, adjunct to opioid analgesics: 25–100 mg every 4–6 hr as needed.
IM (Children ): —0.5–1 mg/kg every 4–6 hr as needed.

Availability ⬆ ⬇

(Generic available)

Tablets: 10 mg; 25 mg; 50 mg
Capsules: 10 mg; 25 mg; 50 mg; 100 mg
Syrup: 10 mg/5 mL
Solution for injection: 25 mg/mL; 50 mg/mL

Assessment ⬆ ⬇

Assess patient for profound sedation and provide safety precautions as indicated (side rails up, bed in low position, call bell within reach, supervision of ambulation and transfer). Geri: Older adults are more sensitive to CNS and anticholinergic effects (delirium, acute confusion, dizziness, dry mouth, blurred vision, urinary retention, constipation, tachycardia). Monitor for drowsiness, agitation, over sedation, and other systemic side effects. Assess falls risk and implement prevention strategies.
Anxiety: Assess mental status (orientation, mood, and behavior).
Nausea and Vomiting: Assess degree of nausea and frequency and amount of emesis.
Pruritus: Assess degree of itching and character of involved skin.

Lab Test Considerations:

May cause false-negative skin test results using allergen extracts. Discontinue hydroxyzine at least 72 hr before test.

Implementation ⬆ ⬇

Do not confuse hydroxyzine with hydralazine, hydrochlorothiazide, hydromorphone, or hydroxyurea.
PO: Tablets may be crushed and capsules opened and administered with food or fluids for patients having difficulty swallowing.
IM: Administer only IM deep into well-developed muscle. Injection is extremely painful. Do not use deltoid site. If must be administered to children, midlateral muscles of the thigh are preferred. Significant tissue damage, necrosis, and sloughing may result from SUBQ or intra-arterial injections. Hemolysis may result from IV injections. Rotate injection sites frequently.

Patient/Family Teaching ⬆ ⬇

Instruct patient to take medication as directed. Take missed doses as soon as remembered unless it is almost time for next dose; do not double doses.
May cause drowsiness or dizziness. Caution patient to avoid driving and other activities requiring alertness until response to medication is known. Geri: Warn patients or caregivers that older adults are at increased risk for CNS effects and falls.
Advise patient to avoid concurrent use of alcohol or other CNS depressants with this medication.
Inform patient that frequent mouth rinses, good oral hygiene, and sugarless gum or candy may help decrease dry mouth. If dry mouth persists for more than 2 wk, consult dentist about saliva substitute.
Rep: Advise females of reproductive potential to avoid hydroxyzine during early pregnancy or use effective contraception and to avoid breastfeeding during therapy. Instruct to notify health care professional if pregnancy is planned or suspected or if breastfeeding.

Evaluation/Desired Outcomes ⬆ ⬇

Decrease in anxiety.
Relief of nausea and vomiting.
Decreased allergic symptoms associated with release of histamine, including pruritus and urticaria.
Sedation when used as a sedative/hypnotic.

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Pronunciation ⬇

Classifications ⬆ ⬇