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HydrOXYzine

Pronunciation

Pronunciation

(hye DROKS i zeen)

Index Terms

  • Hydroxyzine Hydrochloride
  • Hydroxyzine Pamoate
  • Vistaril

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product

Capsule, Oral, as pamoate:

Vistaril: 25 mg, 50 mg

Generic: 25 mg, 50 mg, 100 mg

Solution, Intramuscular, as hydrochloride:

Generic: 25 mg/mL (1 mL [DSC]); 50 mg/mL (1 mL [DSC], 2 mL [DSC], 10 mL [DSC])

Solution, Oral, as hydrochloride:

Generic: 10 mg/5 mL (473 mL [DSC])

Syrup, Oral, as hydrochloride:

Generic: 10 mg/5 mL (25 mL, 118 mL, 120 mL [DSC], 473 mL)

Tablet, Oral, as hydrochloride:

Generic: 10 mg, 25 mg, 50 mg

Brand Names: U.S.

  • Vistaril

Pharmacologic Category

  • Antiemetic
  • Histamine H1 Antagonist
  • Histamine H1 Antagonist, First Generation
  • Piperazine Derivative

Pharmacology

Competes with histamine for H1-receptor sites on effector cells in the gastrointestinal tract, blood vessels, and respiratory tract. Possesses skeletal muscle relaxing, bronchodilator, antihistamine, antiemetic, and analgesic properties.

Absorption

Oral: Rapid

Distribution

Children and Adolescents 1 to 14 years: 18.5 ± 8.6 L/kg (Simons F 1984a); Adults: Vd: 16 ± 3 L/kg (Simons F 1984); Elderly: ~23 L/kg (Simons K 1989); Hepatic dysfunction: ~23 L/kg (Simons F 1989)

Metabolism

Hepatic to multiple metabolites, including cetirizine (active) (Simons F 1989)

Excretion

Urine; active metabolite (cetirizine) is renally eliminated (Simons F 1994)

Onset of Action

Oral: 15 to 30 minutes; Injection: Rapid

Time to Peak

Oral administration: Serum: ~2 hours; Peak suppression of antihistamine-induced wheal and flare: 4 to 12 hours (Simons F 1984)

Duration of Action

Decreased histamine-induced wheal and flare areas: 2 to ≥36 hours; Suppression of pruritus: 1 to 12 hours (Simon F 1984)

Half-Life Elimination

Children and Adolescents 1 to 14 years (mean age: 6.1 ± 4.6 years): 7.1 ± 2.3 hours; Note: Half-life increased with increasing age and was 4 hours in patients 1-year old and 11 hours in a 14-year old patient (Simons F 1984a)

Adults: ~20 hours (Simons 1984); Elderly: ~29 hours (Simons K 1989); Hepatic dysfunction: ~37 hours (Simons F 1989)

Use: Labeled Indications

Treatment of anxiety/agitation (including adjunctive therapy in alcoholism); adjunct to pre- and postoperative analgesia and anesthesia; antipruritic; antiemetic

Contraindications

Hypersensitivity to hydroxyzine or any component of the formulation; early pregnancy; SubQ, intra-arterial, or IV injection

Dosing: Adult

Note: Adjust dose based on patient response.

Antiemetic: IM: 25 to 100 mg/dose

Anxiety:

Oral:

Manufacturer’s labeling: 50 to100 mg 4 times daily

Alternative recommendations (off-label dosing): 37.5 to 75 mg daily in divided doses (WFSBP [Bandelow, 2008]; WFSBP [Bandelow, 2012])

IM: Initial: 50 to 100 mg, then every 4-6 hours as needed

Preoperative sedation:

Oral: 50 to 100 mg

IM: 25 to 100 mg

Pruritus: Oral: 25 mg 3 to 4 times daily

Dosing: Geriatric

Initiate dosing using the lower end of the recommended dosage range due to an increased potential for anticholinergic side effects. Refer to adult dosing.

Dosing: Pediatric

Note: Adjust dose based on patient response.

Antiemetic: IM: 1.1 mg/kg/dose

Preoperative sedation:

Oral: 0.6 mg/kg/dose

IM: 1.1 mg/kg/dose

Pruritus, anxiety: Oral:

<6 years: 50 mg daily in divided doses

≥6 years: 50-100 mg daily in divided dose

Dosing: Renal Impairment

No dosage adjustment provided in the manufacturer’s labeling; however, the following guidelines have been used by some clinicians (Aronoff, 2007): Adults:

GFR >50 mL/minute: No adjustment recommended.

GFR ≤50 mL/minute: Administer 50% of normal dose.

Continuous renal replacement therapy (CRRT), hemodialysis, peritoneal dialysis: Administer 50% of the normal dose.

Dosing: Hepatic Impairment

Change dosing interval to every 24 hours in patients with primary biliary cirrhosis (Simons F, 1989)

Administration

Injection: For IM use only. Do NOT administer IV, SubQ, or intra-arterially. Administer IM deep in large muscle. In adults, the preferred site is the upper outer quadrant of the buttock or midlateral thigh. In children, the preferred site is the midlateral thigh. The upper outer quadrant of the gluteal region should be used only when necessary to minimize potential damage to the sciatic nerve.

Oral: Shake suspension vigorously prior to use.

Compatibility

Y-site administration: Incompatible with allopurinol, amifostine, amphotericin B cholesteryl sulfate complex, doxorubicin liposome, fluconazole, fludarabine, paclitaxel, sargramostim.

Compatibility in syringe: Incompatible with dimenhydrinate, haloperidol, ketorolac, pentobarbital, ranitidine.

Storage

Injection: Store at 20°C to 25°C (68°F to 77°F); excursions permitted to 15°C to 30°C (59°F to 86°F). Protect from light.

Capsules: Store below 30°C (86°F); protect from light.

Solution (hydrochloride salt): Store at 15°C to 30°C (59°F to 86°F); protect from light.

Tablets: Store at 20°C to 25°C (68°F to 77°F).

Drug Interactions

AbobotulinumtoxinA: Anticholinergic Agents may enhance the anticholinergic effect of AbobotulinumtoxinA. Monitor therapy

Acetylcholinesterase Inhibitors: May diminish the therapeutic effect of Anticholinergic Agents. Anticholinergic Agents may diminish the therapeutic effect of Acetylcholinesterase Inhibitors. Monitor therapy

Aclidinium: May enhance the anticholinergic effect of Anticholinergic Agents. Avoid combination

Alcohol (Ethyl): CNS Depressants may enhance the CNS depressant effect of Alcohol (Ethyl). Monitor therapy

Amphetamines: May diminish the sedative effect of Antihistamines. Monitor therapy

Anticholinergic Agents: May enhance the adverse/toxic effect of other Anticholinergic Agents. Exceptions: Levocabastine (Nasal). Monitor therapy

ARIPiprazole: CYP2D6 Inhibitors (Weak) may increase the serum concentration of ARIPiprazole. Management: Monitor for increased aripiprazole pharmacologic effects. Aripiprazole dose adjustments may or may not be required based on concomitant therapy and/or indication. Consult full interaction monograph for specific recommendations. Monitor therapy

Azelastine (Nasal): CNS Depressants may enhance the CNS depressant effect of Azelastine (Nasal). Avoid combination

Barbiturates: HydrOXYzine may enhance the CNS depressant effect of Barbiturates. Management: Consider a decrease in the barbiturate dose, as appropriate, when used together with hydroxyzine. With concurrent use, monitor patients closely for excessive response to the combination. Consider therapy modification

Benzylpenicilloyl Polylysine: Antihistamines may diminish the diagnostic effect of Benzylpenicilloyl Polylysine. Management: Suspend systemic H1 antagonists for benzylpenicilloyl-polylysine skin testing and delay testing until systemic antihistaminic effects have dissipated. A histamine skin test may be used to assess persistent antihistaminic effects. Consider therapy modification

Betahistine: Antihistamines may diminish the therapeutic effect of Betahistine. Monitor therapy

Blonanserin: CNS Depressants may enhance the CNS depressant effect of Blonanserin. Consider therapy modification

Brimonidine (Topical): May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Buprenorphine: CNS Depressants may enhance the CNS depressant effect of Buprenorphine. Management: Consider reduced doses of other CNS depressants, and avoiding such drugs in patients at high risk of buprenorphine overuse/self-injection. Initiate buprenorphine patches (Butrans brand) at 5 mcg/hr in adults when used with other CNS depressants. Consider therapy modification

Cannabis: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Cimetropium: Anticholinergic Agents may enhance the anticholinergic effect of Cimetropium. Avoid combination

CNS Depressants: HydrOXYzine may enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Doxylamine: May enhance the CNS depressant effect of CNS Depressants. Management: The manufacturer of Diclegis (doxylamine/pyridoxine), intended for use in pregnancy, specifically states that use with other CNS depressants is not recommended. Monitor therapy

Dronabinol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Droperidol: May enhance the CNS depressant effect of CNS Depressants. Management: Consider dose reductions of droperidol or of other CNS agents (e.g., opioids, barbiturates) with concomitant use. Consider therapy modification

Eluxadoline: Anticholinergic Agents may enhance the constipating effect of Eluxadoline. Avoid combination

Gastrointestinal Agents (Prokinetic): Anticholinergic Agents may diminish the therapeutic effect of Gastrointestinal Agents (Prokinetic). Monitor therapy

Glucagon: Anticholinergic Agents may enhance the adverse/toxic effect of Glucagon. Specifically, the risk of gastrointestinal adverse effects may be increased. Avoid combination

Glycopyrrolate: Anticholinergic Agents may enhance the anticholinergic effect of Glycopyrrolate. Avoid combination

Glycopyrrolate (Oral Inhalation): Anticholinergic Agents may enhance the anticholinergic effect of Glycopyrrolate (Oral Inhalation). Avoid combination

Highest Risk QTc-Prolonging Agents: QTc-Prolonging Agents (Indeterminate Risk and Risk Modifying) may enhance the QTc-prolonging effect of Highest Risk QTc-Prolonging Agents. Management: Avoid such combinations when possible. Use should be accompanied by close monitoring for evidence of QT prolongation or other alterations of cardiac rhythm. Consider therapy modification

Hyaluronidase: Antihistamines may diminish the therapeutic effect of Hyaluronidase. Management: Patients receiving antihistamines (particularly at larger doses) may not experience the desired clinical response to standard doses of hyaluronidase. Larger doses of hyaluronidase may be required. Consider therapy modification

Hydrocodone: CNS Depressants may enhance the CNS depressant effect of Hydrocodone. Management: Consider starting with a 20% to 30% lower hydrocodone dose when using together with any other CNS depressant. Dose reductions in the other CNS depressant may also be warranted. Consider therapy modification

Ipratropium (Oral Inhalation): May enhance the anticholinergic effect of Anticholinergic Agents. Avoid combination

Itopride: Anticholinergic Agents may diminish the therapeutic effect of Itopride. Monitor therapy

Kava Kava: May enhance the adverse/toxic effect of CNS Depressants. Monitor therapy

Levosulpiride: Anticholinergic Agents may diminish the therapeutic effect of Levosulpiride. Avoid combination

Magnesium Sulfate: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Meperidine: HydrOXYzine may enhance the CNS depressant effect of Meperidine. Management: Consider a decrease in meperidine dose, as appropriate, when used together with hydroxyzine. With concurrent use, monitor patients closely for excessive response to the combination. Consider therapy modification

Methotrimeprazine: CNS Depressants may enhance the CNS depressant effect of Methotrimeprazine. Methotrimeprazine may enhance the CNS depressant effect of CNS Depressants. Management: Reduce adult dose of CNS depressant agents by 50% with initiation of concomitant methotrimeprazine therapy. Further CNS depressant dosage adjustments should be initiated only after clinically effective methotrimeprazine dose is established. Consider therapy modification

Metyrosine: CNS Depressants may enhance the sedative effect of Metyrosine. Monitor therapy

Mianserin: May enhance the anticholinergic effect of Anticholinergic Agents. Monitor therapy

Mifepristone: May enhance the QTc-prolonging effect of QTc-Prolonging Agents (Indeterminate Risk and Risk Modifying). Management: Though the drugs listed here have uncertain QT-prolonging effects, they all have some possible association with QT prolongation and should generally be avoided when possible. Consider therapy modification

Minocycline: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Mirabegron: Anticholinergic Agents may enhance the adverse/toxic effect of Mirabegron. Monitor therapy

Mirtazapine: CNS Depressants may enhance the CNS depressant effect of Mirtazapine. Monitor therapy

Moderate Risk QTc-Prolonging Agents: QTc-Prolonging Agents (Indeterminate Risk and Risk Modifying) may enhance the QTc-prolonging effect of Moderate Risk QTc-Prolonging Agents. Monitor therapy

Nabilone: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

OnabotulinumtoxinA: Anticholinergic Agents may enhance the anticholinergic effect of OnabotulinumtoxinA. Monitor therapy

Orphenadrine: CNS Depressants may enhance the CNS depressant effect of Orphenadrine. Avoid combination

OxyCODONE: CNS Depressants may enhance the CNS depressant effect of OxyCODONE. Management: When oxycodone is combined with another CNS depressant, a dose reduction of one or both agents should be considered. The extended release oxycodone starting dose should be reduced 50% to 67% when initiated in patients already receiving CNS depressants. Consider therapy modification

Paraldehyde: CNS Depressants may enhance the CNS depressant effect of Paraldehyde. Avoid combination

Perampanel: May enhance the CNS depressant effect of CNS Depressants. Management: Patients taking perampanel with any other drug that has CNS depressant activities should avoid complex and high-risk activities, particularly those such as driving that require alertness and coordination, until they have experience using the combination. Consider therapy modification

Potassium Chloride: Anticholinergic Agents may enhance the ulcerogenic effect of Potassium Chloride. Management: Patients on drugs with substantial anticholinergic effects should avoid using any solid oral dosage form of potassium chloride. Avoid combination

Pramipexole: CNS Depressants may enhance the sedative effect of Pramipexole. Monitor therapy

Pramlintide: May enhance the anticholinergic effect of Anticholinergic Agents. These effects are specific to the GI tract. Consider therapy modification

Ramosetron: Anticholinergic Agents may enhance the constipating effect of Ramosetron. Monitor therapy

RimabotulinumtoxinB: Anticholinergic Agents may enhance the anticholinergic effect of RimabotulinumtoxinB. Monitor therapy

ROPINIRole: CNS Depressants may enhance the sedative effect of ROPINIRole. Monitor therapy

Rotigotine: CNS Depressants may enhance the sedative effect of Rotigotine. Monitor therapy

Rufinamide: May enhance the adverse/toxic effect of CNS Depressants. Specifically, sleepiness and dizziness may be enhanced. Monitor therapy

Secretin: Anticholinergic Agents may diminish the therapeutic effect of Secretin. Management: Avoid using drugs with substantial anticholinergic effects in patients receiving secretin whenever possible. If such agents must be used in combination, monitor closely for a diminished response to secretin. Consider therapy modification

Selective Serotonin Reuptake Inhibitors: CNS Depressants may enhance the adverse/toxic effect of Selective Serotonin Reuptake Inhibitors. Specifically, the risk of psychomotor impairment may be enhanced. Monitor therapy

Sodium Oxybate: May enhance the CNS depressant effect of CNS Depressants. Management: Consider alternatives to combined use. When combined use is needed, consider minimizing doses of one or more drugs. Use of sodium oxybate with alcohol or sedative hypnotics is contraindicated. Consider therapy modification

Suvorexant: CNS Depressants may enhance the CNS depressant effect of Suvorexant. Management: Dose reduction of suvorexant and/or any other CNS depressant may be necessary. Use of suvorexant with alcohol is not recommended, and the use of suvorexant with any other drug to treat insomnia is not recommended. Consider therapy modification

Tapentadol: May enhance the CNS depressant effect of CNS Depressants. Management: Start tapentadol at a dose of one-third to one-half of the normal dose if being initiated in a patient who is taking another drug with CNS depressant effects. Monitor closely for evidence of excessive CNS depression. Consider therapy modification

Tetrahydrocannabinol: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Thalidomide: CNS Depressants may enhance the CNS depressant effect of Thalidomide. Avoid combination

Thiazide and Thiazide-Like Diuretics: Anticholinergic Agents may increase the serum concentration of Thiazide and Thiazide-Like Diuretics. Monitor therapy

Tiotropium: Anticholinergic Agents may enhance the anticholinergic effect of Tiotropium. Avoid combination

Topiramate: Anticholinergic Agents may enhance the adverse/toxic effect of Topiramate. Monitor therapy

Trimeprazine: May enhance the CNS depressant effect of CNS Depressants. Monitor therapy

Umeclidinium: May enhance the anticholinergic effect of Anticholinergic Agents. Avoid combination

Zolpidem: CNS Depressants may enhance the CNS depressant effect of Zolpidem. Management: Reduce the Intermezzo brand sublingual zolpidem adult dose to 1.75 mg for men who are also receiving other CNS depressants. No such dose change is recommended for women. Avoid use with other CNS depressants at bedtime; avoid use with alcohol. Consider therapy modification

Test Interactions

May cause false-positive serum TCA screen.

Adverse Reactions

Frequency not defined.

Central nervous system: Dizziness, drowsiness (transient), fatigue, involuntary movements

Gastrointestinal: Xerostomia

Hypersensitivity: Hypersensitivity reaction

Ophthalmic: Blurred vision

Respiratory: Respiratory depression (at higher than recommended doses)

<1% (Limited to important or life-threatening): Fixed drug eruption, hallucination, seizure (at considerably higher than recommended doses), skin rash, tremor (at considerably higher than recommended doses)

Warnings/Precautions

Concerns related to adverse effects:

• CNS depression: May cause CNS depression, which may impair physical or mental abilities; patients must be cautioned about performing tasks which require mental alertness (eg, operating machinery or driving).

Disease-related concerns:

• Glaucoma: Use with caution in patients with narrow-angle glaucoma; condition may be exacerbated by cholinergic blockade. Screening is recommended.

• Prostatic hyperplasia/urinary stricture: Use with caution in patients with prostatic hyperplasia and/or urinary stricture.

• Respiratory disease: Use with caution in patients with asthma or COPD.

Concurrent drug therapy issues:

• Sedatives: Effects may be potentiated when used with other sedative drugs or ethanol.

Dosage form specific issues:

• Benzyl alcohol and derivatives: Some dosage forms may contain benzyl alcohol and/or sodium benzoate/benzoic acid; benzoic acid (benzoate) is a metabolite of benzyl alcohol; large amounts of benzyl alcohol (≥99 mg/kg/day) have been associated with a potentially fatal toxicity (“gasping syndrome”) in neonates; the “gasping syndrome” consists of metabolic acidosis, respiratory distress, gasping respirations, CNS dysfunction (including convulsions, intracranial hemorrhage), hypotension and cardiovascular collapse (AAP ["Inactive" 1997]; CDC, 1982); some data suggests that benzoate displaces bilirubin from protein binding sites (Ahlfors, 2001); avoid or use dosage forms containing benzyl alcohol and/or benzyl alcohol derivative with caution in neonates. See manufacturer’s labeling.

Other warnings/precautions:

• Appropriate administration: For IM use only. Subcutaneous, IV, and intra-arterial routes of administration are contraindicated. Intravascular hemolysis, thrombosis, and digital gangrene have been reported with IV or intra-arterial administration (Baumgartner, 1979); SubQ administration may result in significant tissue damage. If inadvertent IV administration results in extravasation, stop infusion immediately and disconnect (leave cannula/needle in place); gently aspirate extravasated solution (do NOT flush the line); remove needle/cannula; elevate extremity.

Monitoring Parameters

Relief of symptoms, mental status, blood pressure

Pregnancy Considerations

Adverse events were observed in animal reproduction studies. Hydroxyzine crosses the placenta. Maternal hydroxyzine use has generally not resulted in an increased risk of birth defects. Use of hydroxyzine early in pregnancy is contraindicated but hydroxyzine is approved for pre- and postpartum adjunctive therapy to reduce opioid dosage, treat anxiety, and control emesis. Antihistamines are recommended for the treatment pruritus with rash in pregnant women (although second generation antihistamines may be preferred). Antihistamines are not recommended for treatment of pruritus associated with intrahepatic cholestasis in pregnancy. Possible withdrawal symptoms have been observed in neonates following chronic maternal use of hydroxyzine during pregnancy.

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)

• Patient may experience xerostomia or fatigue. Have patient report immediately to prescriber difficulty with motor activity or illogical thinking (HCAHPS).

• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for healthcare professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience and judgment in diagnosing, treating and advising patients.

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