Atarax side effects and drug information

Atarax is hydroxyzine, and this drug works in several different ways, such as decreasing the activity in the central nervous system as well as functions as an antihistamine that diminishes the natural histamine present in the body. Histamines make us develop hives or rashes in the skin or causes runny nose or sneezing.

ChemSpider ID 3531
Trade name Atarax, Vistaril
ChemSpider ID 3531
CAS ID 68-88-2
Molar mass 374.904 g/mol
Read up


Atarax is also used as a treatment for tension and anxiety, so in this way, it works as a sedative. It can also be used to treat some types of allergic reactions, such as contact dermatitis or hives. This medication may be used along with other medicines that are given for anesthesia.

Important Information

It is not recommended to use this drug if you are allergic to hydroxyzine, and also if you are pregnant. Atarax may also distort reactions and thinking, and it does not go well with alcohol, so try to avoid drinking alcohol while on treatment with this drug.  

If you start experiencing symptoms such as confusion, tremors, restless muscle movements in the neck, jaw, eyes, or tongue, or seizures, it is best to stop using this medicine.  

Before beginning treatment with Atarax, inform your health care provider if you have the following conditions:

  • Liver disease
  • Seizure disorder
  • Asthma
  • Kidney disease
  • Glaucoma
  • Emphysema
  • Heart disease
  • High blood pressure
  • Stomach ulcer
  • Thyroid discomfort

Side Effects

Though taking drugs that contain hydroxyzine hydrochloride may cause potential side effects, these reactions are usually temporary and generally mild.  

Anticholinergic reactions tend to produce dry mouth, while reactions affecting the central nervous system usually cause drowsiness that goes away after a few days and is temporary. Side effects affecting involuntary motor activity, though very rare, may cause convulsions and tremors. These types of uncommon or rare side effects are usually experienced for those who are given higher dosages.

Indication and Dosage

Dosages may be adjusted according to various factors that include age, the condition being treated, and how the patient responds to the therapy. The form of administration may vary as well, depending on the patient’s condition and his or her ability to take in the medication. This drug is commonly administered orally, but if this is not possible, treatment may also be given through intramuscular route.

For indicative relief of anxiety and tension that are related to psychoneurosis

Dosage for this type of treatment are:

  • For adults, the usual dose is at 50 to 100mg q.i.d
  • For children below six years old, the usual dose is at 50mg per day and is given in divided dosages
  • For children above six years old, the usual dose is at 50 to 100mg daily and is administered in divided dosages

To manage severe itching sensations caused by allergic reactions or conditions such as contact and atopic dermatoses, chronic urticaria, or histamine- related 

Dosage for this kind of treatment are:

  • For adults, usual dosage given is 25mg t.i.d or q.i.d
  • For children under six years old, the usual dosage is at 50mg daily and is given in divided doses
  • For children over six years old, the usual dosage is at 50 to 100mg and is administered in divided doses

When used as a sedative following general anesthesia or as a premedication

Dosage for this purpose are the following:

  • For adults, general dosage is at 50 to 100mg
  • For children, the general dose given is at around 0.6mg/kg of the body weight

Warnings and Precautions

The use of Atarax or medicines that contain hydroxyzine must be used with caution in some conditions as it may result in certain side effects. That is why it is very important for people who would be starting treatment with this drug to inform their doctor about their medical conditions and if they are taking any other type of medication.  

For breastfeeding mothers

Although there is no confirmation yet if this drug can be passed into human milk, the use of hydroxyzine is not advised for the breastfeeding mothers.

For tablets only

The tablet form of this drug is produced using 1,1,1- trichloroethane, which is a type of substance that may cause harm to human health and damage the environment as it may destroy the upper atmosphere of the ozone layer.  


When under treatment for this drug, avoid drinking alcohol as its effects may be increased; and also avoid driving or using machinery as this medication may cause drowsiness.  

Since hydroxyzine causes enhancing actions, taking it along with other CNS depressants such as barbiturates, analgesics, narcotics as well as non- narcotics must be given great considerations. When used with these types of drugs, hydroxyzine dosage should be reduced.

Geriatric Use

No confirmation has been determined as of yet with regards to the difference in response between younger and older patients who are using this product, though, in some studies, it did not show any difference.

The use of this drug on the elderly must be done in caution as they are more likely to experience side effects such as oversedation and confusion. As for effect on their renal excretion, no data has yet been determined.  

If this treatment should be given to the elderly, the lowest possible dosage should be prescribed, and they should be monitored closely.

Overdose and Contraindications

During clinical trials using animals as a subject, when this drug was given to pregnant rats, rabbits, and mice, there were abnormalities in the fetuses of the rat and the mouse. The dosage administered was significantly higher than the usual therapeutic range used in humans.

As for effect in a human fetus, there is no substantial data to provide information with regards to safe usage during early pregnancy.  

This drug should not be used by those who have hypersensitivity to hydroxyzine. And for overdosage, the common symptom is hypersecretion.  

Should vomiting occur, gastric lavage must be done immediately along with constant monitoring of the patient and by providing supportive care.

Clinical Pharmacology

Based on pharmacological and clinical studies, hydroxyzine that is given in therapeutic dosage does not lead to an increase in acidity or gastric secretion and showed mild antisecretory reactions.

It is quickly absorbed from the gastrointestinal tract, and its effects occur within 15 to 30 minutes following oral administration