Hydroxyzine

What is Hydroxyzine?

Hydroxyzine is a prescription-only medicine widely used to manage allergic conditions and relieve symptoms of anxiety and tension. It contains hydroxyzine hydrochloride or hydroxyzine pamoate as its active ingredients.

It belongs to the antihistamine class of drugs, but also exhibits anticholinergic and sedative properties. Chemically, hydroxyzine is synthesised through a series of organic reactions to create a compound that effectively blocks histamine H1-receptors in the body.

Generic Names:

• Hydroxyzine: The internationally recognised generic name for the active chemical compound.

Global Brand Names:

Hydroxyzine is distributed globally under several prominent brand names.

• Atarax: A widely recognised brand name formulating the drug as hydroxyzine hydrochloride.
• Vistaril: A major brand name specifically utilizing the hydroxyzine pamoate formulation.
• Iterax: An alternative brand name available in various international healthcare markets.

These names all refer to the same medication. It is important to note that while the active ingredient is the same, different countries may have different regulations and available medication formulations.

What is Hydroxyzine used for?

Hydroxyzine is used to relieve:

• Itching and skin irritation caused by allergic reactions.
• Symptoms of anxiety and tension related to emotional or psychological conditions.
• Nausea and vomiting.
• Symptoms associated with alcohol withdrawal.
• Anxiety prior to or alongside clinical anaesthesia.

How do you use Hydroxyzine?

Availability:

• Tablet
• Syrup
• Injection

Suitability:

• Adults: Yes, for indicated conditions.
• Elderly: Yes, but with caution due to increased sensitivity to side effects.
• Children: Yes, but requires strict caution and medical supervision for young children and infants.
• Pregnant Women: No, particularly in early pregnancy due to fetal abnormality risks observed in animal studies (US FDA Category C).
• Breastfeeding Women: No, as the drug can pass into breast milk.

Dosage Information:

• Adults (Anxiety and tension): 50 mg to 100 mg taken four times a day as hydroxyzine pamoate.
• Adults (Allergies): 25 mg taken three to four times a day as hydroxyzine hydrochloride.
• Elderly: Lower initial doses are generally required.
• Children: Dosages are strictly calculated based on the child's age and specific condition.

Who cannot take Hydroxyzine?

• Patients with a history of hypersensitivity to hydroxyzine.
• Individuals with a known allergy to cetirizine.
• Women in early pregnancy, due to the risk of fetal abnormalities.
• Nursing mothers, as the medication passes into breast milk.

Allergies and unsuitability:

• Not suitable for individuals with a known allergy to hydroxyzine or cetirizine.

Warnings and precautions:

• Take the medication with a full glass of water, either with or without food.
• Do not drive or operate machinery, as there is a high risk of drowsiness and impaired alertness.
• Exercise caution if you have a history of heart problems, glaucoma, urinary retention, or thyroid disorders.

Interactions and contraindications:

• Avoid alcohol to prevent dangerously enhanced drowsiness and sedation.
• Check with a doctor before taking other central nervous system (CNS) depressants or anticholinergic drugs.

Conditions where the drug should not be used:

• Early pregnancy.
• Active lactation.
• Known hypersensitivity to hydroxyzine or cetirizine.

Common side effects of hydroxyzine include drowsiness, dry mouth, and headaches. While these are generally mild, adverse reactions can escalate. Severe side effects are rare but may involve an irregular heartbeat and seizures, requiring immediate medical intervention.

Warnings and precautions:

• Take the medication with a full glass of water, either with or without food.
• Do not drive or operate machinery, as there is a high risk of drowsiness and impaired alertness.
• Exercise caution if you have a history of heart problems, glaucoma, urinary retention, or thyroid disorders.

Interactions and contraindications:

• Avoid alcohol to prevent dangerously enhanced drowsiness and sedation.
• Check with a doctor before taking other central nervous system (CNS) depressants or anticholinergic drugs.

Conditions where the drug should not be used:

• Early pregnancy.
• Active lactation.
• Known hypersensitivity to hydroxyzine or cetirizine.

Storage information:

• Store at room temperature in a dry place.
• Protect the medication from direct light and excessive moisture.
• Keep strictly out of reach of children and pets.

Handling instructions:

• Use the designated measuring device or spoon provided with the liquid syrup to ensure an accurate dose.
• Suck on sugarless candy or ice chips to manage dry mouth symptoms effectively.

Where is Hydroxyzine available in Hong Kong?

Hydroxyzine is classified as a Prescription Only Medicine in Hong Kong. Patients must present a valid doctor's prescription to purchase it.

It can be obtained at registered pharmacy dispensaries displaying the "Rx" logo or collected directly from a hospital or private clinic dispensary following a consultation.