Hydroxyzine (Atarax) Interactions
- Amantadine
- Amoxapine
Antimuscarinics
Anxiolytics, Sedatives, and Hypnotics
Barbiturates
- Buprenorphine
- Butorphanol
- Cetirizine
- Clozapine
- Cyclobenzaprine
- Dextroamphetamine
- Disopyramide
- Dronabinol, THC
- Entacapone
- Ethanol
General Anesthetics
- Haloperidol
- Maprotiline
Monoamine oxidase inhibitors (MAOIs)
- Nalbuphine
- Olanzapine
Opiate agonists
- Orphenadrine
- Pentazocine
Phenothiazines
- Pramipexole
- Pregabalin
- Risperidone
- Ropinirole
Sedating H1-blockers
- Tolcapone
- Trazodone
Tricyclic antidepressants
Hydroxyzine (Atarax) Interactions
Because hydroxyzine causes pronounced sedation, an enhanced CNS depressant effect may occur when it is combined with other sedating H1-blockers or with cetirizine. Due to the duplicative pharmacology and potential for additive side effects, combination of hydroxyzine with other antihistamines is not generally recommended.
MAOIs may prolong and intensify the anticholinergic effects of antihistamines. The anticholinergic activity of MAOIs is minimal; however, anticholinergic effects sometimes occur. It is recommended that the concurrent use of MAOIs with drugs possessing anticholinergic activity be avoided, especially atropine and scopolamine, since their effects and those of other anticholinergic drugs are potentiated and may become severe. Most manufacturers recommend that H1-antagonists not be used within two weeks of therapy with a MAOI.
Because hydroxyzine causes pronounced sedation, an enhanced CNS depressant effect may occur when it is combined with other CNS depressants including anxiolytics, sedatives, and hypnotics, barbiturates, buprenorphine, butorphanol, dronabinol, THC, entacapone, ethanol, haloperidol, general anesthetics, nalbuphine, opiate agonists, pentazocine, pramipexole, pregabalin, risperidone, ropinirole, tolcapone, trazodone, tramadol, or with other sedating H1-blockers.
The anticholinergic effects of hydroxyzine are moderate and may be enhanced when combined with other antimuscarinics. Other commonly used drugs with moderate to significant anticholinergic effects include amantadine, amoxapine, clozapine, cyclobenzaprine, disopyramide, maprotiline, olanzapine, orphenadrine, most phenothiazines, and most tricyclic antidepressants. Clinicians should note that antimuscarinic effects might be seen not only on GI smooth muscle, but also on bladder function, the eye, and temperature regulation. With many of the listed agents, additive drowsiness may also occur when combined with sedating antihistamines.
Similar to phenothiazine H1-antagonists, hydroxyzine has been reported to inhibit and reverse the vasopressor effect of epinephrine; therefore, if treatment with a vasopressor agent is necessary, norepinephrine should be used.
Dextroamphetamine and other amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia or for sedation induction. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
[ Last revised: 2/16/2005 4:27:00 PM ]
References
. Dexedrine® (dextroamphetamine) package insert. Research Triangle Park, NC; GlaxoSmithKline; 2002 Jan.
. Zyrtec® (cetirizine) package insert. New York, NY: Pfizer Labs; 2004 Mar.
. Periactin® (cyproheptadine) package insert. West Point, PA: Merck and Company, Inc.; 1999 Jan.
. Hoffman BB, Lefkowitz RJ. Atropine, scopolamine, and related antimuscarinic drugs. Gilman AG, Rall TW, Nies AS, Taylor P, (eds.) In: Goodman and Gilman’s Pharmacological Basis of Therapeutics. 8th ed., New York, Pergamon Press. 1990. 150 - 61.
. Seixas FA. Alcohol and its drug interactions. Ann Intern Med 1975;83:86 - 92.
. Hoffman BB, Lefkowitz RJ. Monoamine oxidase (MAO) inhibitors. Gilman AG, Rall TW, Nies AS, Taylor P, (eds.) In: Goodman and Gilman’s Pharmacological Basis of Therapeutics. 8th ed., New York, Pergamon Press. 1990. 416 - 17.
. Welch MJ, Meltzer EO, Simons FE. H1-antihistamines and the central nervous system. Clin Allergy Immunol 2002;17:337 - 88.
. Atarax® (hydroxyzine) tablets and syrup package insert. New York, NY: Pfizer Roerig; 2001.
. Frampton JE, Foster RH. Pregabalin: in the treatment of postherpetic neuralgia. Drugs. 2005;65:111 - 8.
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