Hydroxyzine
Also known as: Atarax, Vistaril, Masmoran, Ucerax
- **Drowsiness is common**: Your pet may seem sleepy or lethargic, especially when starting the medication. This is normal, but contact your veterinarian if it seems excessive. - **Working Dogs**: This medication can impede the performance and alertness of working, hunting, or service dogs. - **Consistency is key**: Antihistamines often work best when given consistently to *prevent* allergic flare-ups rather than treating them once they are severe. - **Allergy Testing**: If your pet is scheduled for intradermal skin allergy testing, you will need to stop this medication 3 to 7 days prior. Consult your veterinarian for exact timing. - **Do not double dose**: If you miss a dose, give it when you remember, but never give two doses at once.
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
What it is used for
- For pruritus
- For pruritus
- For frequently recurrent idiopathic lower urinary tract disease
- General
- General
- General
- For pruritus associated with allergies, feather picking, or self-mutilation
- For pruritus associated with allergies, feather picking, or self-mutilation
- As an antipruritic/antihistamine
- For flea allergy dermatitis
How it is given
Possible side effects
- Sedation (most common, usually mild and transient in dogs)
- Hyperexcitability (occasional paradoxical reaction)
- Fine rapid tremors (dogs)
- Whole body tremors (dogs)
- Seizures (rare in dogs)
- Polydipsia (cats)
- Depression (cats)
- Behavioral changes (cats)
- Sedation / Lethargy
- Dry mouth
- Urinary retention
- Gastrointestinal upset
- Paradoxical excitation (rare)
Cautions & contraindications
- Hypersensitivity to hydroxyzine or its metabolites (e.g., cetirizine)
- Known hypersensitivity to hydroxyzine or cetirizine
- Early pregnancy (teratogenic in some animal models)
- Use with caution in patients with **prostatic hypertrophy**, **bladder neck obstruction**, **severe cardiac failure**, **angle-closure glaucoma**, or **pyeloduodenal obstruction** due to its anticholinergic effects. > **Pregnancy Warning**: At doses substantially greater than those used therapeutically, hydroxyzine has been shown to be teratogenic in lab animals. Use during pregnancy (particularly during the first trimester) only when the benefits outweigh the risks (FDA Category C). It is unknown if hydroxyzine enters maternal milk, but its active metabolite cetirizine does.
Drug interactions
- Anticholinergic agents: Additive anticholinergic effects may occur when used concomitantly.
- CNS Depressant Drugs (e.g., barbiturates, tranquilizers): Additive CNS depression may be seen.
- Epinephrine: Hydroxyzine may inhibit or reverse the vasopressor effects of epinephrine; use norepinephrine or metaraminol instead.
- CNS Depressants (e.g., opioids, barbiturates, gabapentin): Additive CNS depression and sedation
Frequently asked questions
What is Hydroxyzine used for in pets?
- **Drowsiness is common**: Your pet may seem sleepy or lethargic, especially when starting the medication. This is normal, but contact your veterinarian if it seems excessive. - **Working Dogs**: This medication can impede the performance and alertness of working, hunting, or service dogs. - **Consistency is key**: Antihistamines often work best when given consistently to *prevent* allergic flare-ups rather than treating them once they are severe. - **Allergy Testing**: If your pet is scheduled for intradermal skin allergy testing, you will need to stop this medication 3 to 7 days prior. Consult your veterinarian for exact timing. - **Do not double dose**: If you miss a dose, give it when you remember, but never give two doses at once.
Is Hydroxyzine safe for my pet?
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
This article is for general education and is not a substitute for professional veterinary advice. If your pet is unwell, please consult a veterinarian.
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