Hydroxyzine Overdose (A brief guide)

In this brief guide, we will discuss what it is understood by Hydroxyzine overdose, how it is usually taken, how it works and possible side effects.

Remember this guide is by no means intended to replace seeking medical guidance or advice.

Hydroxyzine overdose

Hydroxyzine  hydrochloride is used as an allergy treatment. It is an antihistamine and works by blocking the production of histamine, which is a natural substance that your body produces during an allergic reaction.

It is also known to be used short-term to treat anxiety, due to its sedative properties, and can even be used before and after surgery.

Hydroxyzine is the chemical name of the drug but pharmaceutical companies have many commercial names that you might have probably heard of, such as Vistaril or Atarax. 

How to use Hydroxyzine?

Your doctor will provide specific instructions on how to take Hydroxyzine but usually, it is prescribed to be taken three to four times a day (orally) and it can be taken with or without food (in comparison to other drugs). 

It is very important you take the exact dose your doctor prescribed and be extra careful especially when taking the liquid form of this medication.

Additionally, your doctor will prescribe the dosage depending on your age, medical condition and response to treatment. In children, the dosage may depend also on how much you weight.   

In adults, the recommended dosage of Hydroxyzine is mentioned below but remember how important it is to take the exact amount your doctor recommended specifically for you. 

Adult Dosage Forms and Strength:

  • Tablets: they come in doses of 5 mg, 25 mg or 50 mg
  • Capsule: they come in doses of 25 mg, 50 mg or 100 mg
  • Syrup/oral suspension: It comes in the dose of 10 mg/5mL 
  • Injectable solution: it comes in doses of 25 mg/5mL and 50 mg/5mL

Most common side Effects

Side effects of Hydroxyzine consumption can vary, but here is a list of the most common:

  • Drowsiness
  • Dizziness
  • Blurred Vision
  • Constipation
  • Dry mouth

Additional and serious side effects need to be reported to your doctor as soon as possible and some of them can include:

  • Mental or mood changes such as restlessness, confusion or hallucinations.
  • Tremors (shaking)
  • Difficulties urinating

We can’t stress enough how important it is for you to take the exact dose your doctor prescribed, be especially extra careful if you are taking the liquid form of this medication. 

In terms of dosage and posology, Hydroxyzine is recommended to be taken for the shortest amount of time possible and at the lowest effective dose. 

In adults and children that weight 40 kg or more, the maximum daily dose is 100 mg per day.

Additionally and in regards to Hydroxyzine for anxiety (adults), it is recommended to be taken daily in divided doses between 50-100 mg.

Also, it might happen that you forget to take your medication because you were busy or simply forgot. 

Don’t panic!  just as soon as you remember to take the missing dosage but if it’s now getting closer for the next dosage just skip the one you forgot and keep taking them as you normally would.  

What if I am taking other drugs with Hydroxyzine?

In addition, be aware that when Hydroxyzine interacts with other substances it might reduce the effectivity and increase the chance of developing some of the side effects, so try keeping a list of the medicine or substances you are actually taking so you can consult them with your doctor.

Since Hydroxyzine might cause drowsiness, tell your doctor or pharmacist if you are simultaneously taking any opioid or cough medicine such as codeine or hydrocodone, if you are a cannabis user, take other anxiety meds such as alprazolam, zolpidem or lorazepam, or if you are taking other antihistamines as diphenhydramine or promethazine.

Currently, there are about 75 drugs known to have mayor interaction with Hydroxyzine. Here we list some of them:

  • Alfentanil
  • Buprenorphine
  • Amiodarone
  • Citalopram
  • Grepafloxacin
  • Levomethadyl acetate
  • Tramadol
  • Sufentanil
  • Anagrelide
  • Potassium chloride
  • Oxycodone
  • Quinidine
  • Methadone
  • Morphine
  • Escitalopram
  • Dolasetron
  • Arsenic trioxide
  • Haloperidol
  • Codeine

Hydroxyzine Overdose: Symptoms to be aware!

If you or someone close experiences some of the following symptoms it could be an indication of Hydroxyzine overdose:

  • Being unresponsive or decreased awareness
  • Feeling extremely sleepy or lethargic
  • Feeling nauseous 
  • Having seizures
  • Vomiting

If you are experiencing these symptoms or someone close to you is, you should immediately seek urgent medical assistance. 


  • It is important that you always follow the instructions indicated by your doctor. 
  • Keep taking the medicine even if you start to feel better and try not to miss any doses. You could set an alarm or reminder on your phone so it tells you when it’s time for your next dosage. 
  • Always check the labels on all your medicines since they can give you additional component information and avoid having allergic reactions. 
  • Contact your doctor, if you start having seizures, mood swings, hallucinations, tremors, facial swelling, have difficulties urinating, confusion or if your heartbeat is going faster than usual or is irregular.
  • While you get used to using this medicine and identify how you react to it, avoid handling any type of machinery or drive a vehicle.
  • Let your doctor know if you are allergic to the chemical components of Cetirizine or Levocetirizine. 
  • Inform your doctor of any other important allergies you might have.
  • Avoid alcohol consumption while on this medication because this interacts with the medicine to increase the risk of side effects.
  • If you have other medical conditions such as liver disease, diabetes or any other that requires you to avoid or limit your sugar consumption then, be extra careful when taking the liquid form of Hydroxyzine. 
  • Provide your doctor with your complete or most accurate medical history or related conditions, especially if you have breathing problems such as emphysema or asthma, glaucoma, high blood pressure or kidney problems.

User reviews for Hydroxyzine overdose on Drugs.com

November 27, 2019

“Does not make me sleepy or less anxious.”




Taken for 1 to 6 months

November 25, 2019

“Ok so my doctor’s PA gave me hydroxyzine to ease my nighttime itchiness (eczema) and it’s started making me shake severely, have tightness in my chest, and makes my breathing feel a little laboured. Unfortunately, she has me on other meds to which I’m beginning to believe I’m allergic to. Going to stop taking hydroxyzine until I can see my new doctor. Don’t ignore these horrible symptoms as they’re not normal! 3-5 hours to go before it’s supposed to work its way out of my system…this.is.awful.”




Taken for 1 to 6 months

November 23, 2019

“my doctor prescribed me 25mg Hydroxyzine for my severe anxiety, social anxiety panic attacks and PTSD. I take 1/2 tabs four times daily as needed for my severe anxiety. I am giving this drug a 8 because it does NOT work with panic attacks but it does work amazing with anxiety. I am also on Xanax 1 mg as needed for my severe panic attacks which I usually have about 2-3 times a day. Some days are better and worst but Hydroxyzine been helping keep me calm. Also I am on 60mg of Cymbalta and this stuff works amazing. So with the combo xanax, hydroxyzine and cymbalta, my life is back to normal and social anxiety panic attacks and PTSD controlled and I feel myself again.”


Frequently asked questions (FAQ’s) for Hydroxyzine overdose

How much hydroxyzine can you take in a day?

The recommended dose of Vistaril (Hydroxyzine) to treat itch or pruritus is 24 mg to be taken 3 to 4 times a day.

For sedation, the recommended dose is 50 to 100 mg and the dose recommended for anxiety and tension treatment  is 50 to 100 mg 4 times daily.

What is the medicine vistaril used for?

Vistaril is the commercial name for Hydroxyzine.

This drug acts as an antihistamine that reduces the effects of the naturally produces histamine in our body.

Histamine produces allergy related symptoms such as itching or hives on the skin.

It is also used as a sedative for anxiety and tension treatment. 

Is Hydroxyzine the same thing as Xanax?

Hydroxyzine and Xanax are not the same types of drugs, even if they are both used as part of anxiety treatment.

In nature, Hydroxyzine is an antihistamine with anticholinergic and sedative properties and Xanax is considered a benzodiazepine.

Is Vistaril a narcotic?

Vistaril is not considered a narcotic because it is not regarded as addictive in the same way narcotics are.

It is generally regarded as safe for people with substance use disorders.

Often prescribed in substance abuse treatment centers for anxiety and due to its sedative properties is also prescribed as a sleeping aid. 

Is vistaril a sleeping pill?

Vistaril is not considered as a sleeping pill but due to its sedative properties it is also prescribed as a sleeping aid. 

Why is this post about Hydroxyzine important?

This blog post about Hydroxyzine is important because it helps understand what Hydroxyzine is, how is it usually taken, forms and doses and possible side effects.
If you are taking this drug or someone else you know, always make sure to follow the doctor’s instructions and stay alert to identify any warning signs so you can be prepared to act in case of an emergency.

Please feel free to comment on the content or ask any questions in the comments section below!

  1. Focus On: 70 Most Popular Sedatives: Sedative, Methaqualone, Ethanol, Ketamine, Quetiapine, Diphenhydramine, Gamma-Hydroxybutyric Acid, Hydroxyzine, Sodium Thiopental, Date rape Drug, etc.
  2. Hydroxyzine (Hydrochloride): Treats Anxiety, Nausea, Vomiting, Allergies, Skin Rash, Hives, Itching, and Alcohol Withdrawal Symptoms Paperback – 21 Apr 2015
  3. [(Hydroxyzine – A Medical Dictionary, Bibliography, and Annotated Research Guide to Internet References)] [By (author) Icon Health Publications] published on (March, 2004)
  4. Hydroxyzine: Webster’s Timeline History, 1956 – 2007 Paperback – 17 May 2010
  5. Side Effects of Drugs Annual: A Worldwide Yearly Survey of New Data in Adverse Drug Reactions (ISSN Book 38)


Drugs.com: Hydroxyzine



National Institute for Health Care and Excellence

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