Hydroxyzine is an antihistamine. While antihistamines most commonly treat allergies, hydroxyzine is also prescribed for the treatment of anxiety.
However, hydroxyzine has some anticholinergic properties, meaning it blocks the action of acetylcholine. This brain chemical (or neurotransmitter) plays a role in many bodily functions, including muscle contraction and digestion.
So taking anything with anticholinergic properties increases the risk of side effects.
To help you understand more about hydroxyzine, in this article, I’ll explain what it’s used for, its possible side effects, drug interactions, and potential alternatives.
I’ll also discuss when to see a healthcare provider about hydroxyzine.
Hydroxyzine Usage
Hydroxyzine is a first-generation H-1 receptor antihistamine in the same class of medications as diphenhydramine (Benadryl).
H-1 antihistamines work on histamine 1 receptors, which are found throughout the body in:
Cardiac tissue
The gastrointestinal tract
Cells lining blood vessels
Respiratory smooth muscle
Immune cells
The uterus
The central nervous system
When the H-1 receptor at any of these locations is stimulated, it results in common symptoms associated with allergies such as:
Fluid moving between blood vessels
Flushing from the dilation of veins
Stimulation of airways leading to coughing
Smooth muscle contraction in the lungs and gastrointestinal tract
Hives, rashes, and anaphylaxis in extreme reactions
Hydroxyzine can minimize the effects of histamine and may be prescribed for:
Itching from skin reactions such as hives or contact dermatitis
Symptoms of anxiety, including generalized anxiety disorder (GAD)
Tension
Sedation before general anesthesia
Allergic reactions
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Common dosage
Hydroxyzine is available as a generic drug and under the brand names Atarax and Vistaril.
The common dosage for hydroxyzine depends on the reason it is prescribed:
Anxiety: 50-100 mg, four times per day
Skin reactions: 25 mg, 3-4 times per day
Allergies: 25 mg, 3-4 times per day
For any diagnosis, healthcare providers prescribe the lowest effective dose of hydroxyzine to minimize the risk of side effects.
Is hydroxyzine habit forming?
Unlike other anti-anxiety medications, the use of hydroxyzine is not habit-forming.
How quickly does hydroxyzine work?
Hydroxyzine easily crosses the blood-brain barrier and produces an effect quickly, usually in 15-30 minutes.
The half-life of hydroxyzine is three hours, meaning it begins to wear off by then.
Most of its effects will stop within 4-6 hours.
Hydroxyzine Side Effects
Hydroxyzine causes some common side effects related to it being an antihistamine and also due to its anticholinergic effects.
In rare cases, these effects may be more serious.
Common side effects
Common side effects of hydroxyzine may include:
Drowsiness, sleepiness, and fatigue
Headache
These side effects may be more noticeable with higher dosages or when suddenly changing dosages.
More serious side effects
Less commonly, hydroxyzine can cause serious side effects.
If you experience severe reactions such as those below, discontinue hydroxyzine and talk to your healthcare provider immediately:
Seizures
Unintentional tremoring, trembling, or shaking
Pus-filled or blister-like sores
Skin redness
Fever
Hydroxyzine Drug Interactions
Hydroxyzine may interact with other medications.
To avoid complications, always tell your healthcare provider everything that you take, including prescription drugs, over-the-counter (OTC) medicines, vitamins, supplements, and herbs.
Do not take the following medications if you take hydroxyzine:
Other sleeping pills, sedatives, or tranquilizers
Other antihistamines
Narcotics
Muscle relaxers
Certain antidepressants such as citalopram (Celexa) or fluoxetine (Prozac)
Antipsychotics
Anticonvulsants
Certain antibiotics such as azithromycin (Zithromax), clarithromycin (Biaxin), erythromycin (Eryc), and others
Certain heart rhythm medications such as amiodarone (Cordarone, Nexterone, others), quinidine (Nuedexta), sotalol (Sorine, Sotylize), and others
Certain cancer treatments
Malaria medication
Medication for HIV/AIDS
Anti-nausea medications such as ondansetron (Zofran)
What to avoid
Certain medical conditions make hydroxyzine unsafe.
Do not take hydroxyzine if you have:
Allergies to any ingredients in hydroxyzine
Allergies to cetirizine (Zyrtec) or levocetirizine (Xyzal)
Prolonged QT interval on an EKG
A history of heart attack, heart failure, or heart disease
A history of low blood levels of potassium or magnesium
Additionally, older adults (over age 65) should not take hydroxyzine. Other medications are safer and effective for this age group.
Due to an increased risk of birth defects, do not take hydroxyzine if you are pregnant, plan to become pregnant, or are breastfeeding.
Hydroxyzine can make you very sleepy. Do not take hydroxyzine if you have to operate a vehicle or machinery until you know how the medication affects you.
Because it’s a depressant, alcohol can increase the effects of hydroxyzine. Do not consume alcohol while you are taking hydroxyzine.
Hydroxyzine Alternatives
Alternatives to hydroxyzine depend on the reason the medication was prescribed and may include:
For anxiety: alprazolam (Xanax)
For skin or allergic reactions: diphenhydramine (Benadryl)
However, alprazolam is a controlled substance that can be habit-forming and comes with a risk of addiction, so hydroxyzine is often a preferred anxiety treatment.
And diphenhydramine is typically only used for short-term allergies or reactions.
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Refill medications and get certain necessary prescriptions.
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When to See a Doctor
If you have questions about the use of hydroxyzine for allergies or anxiety, a healthcare provider can identify whether it is appropriate for you.
If you have anxiety that impacts your quality of life, talk to a healthcare provider. They can recommend treatment, which may include medication, therapy, lifestyle changes, or a combination of treatment options.
How K Health Can Help
Think you might need a prescription for Vistaril (hydroxyzine)?
K Health has clinicians standing by 24/7 to evaluate your symptoms and determine if hydroxyzine is right for you.
Get started with our free assessment, which will tell you in minutes if treatment could be a good fit. If yes, we’ll connect you right to a clinician who can prescribe medication and have it shipped right to your door.