How Do Antihistamine Piperazine Derivatives Work?

Antihistamine piperazine derivatives are histamine H-1 receptor antagonists used to treat anxiety, chronic urticaria (skin rash associated with food allergy), pruritis (itching), and preoperative sedation.

Hydroxyzine is an inverse agonist of histamine H-1 receptor which decreases the activity of the receptor and inhibits the release of histamine. This results in inhibition of smooth muscle contractions and prevents bronchoconstriction, vasoconstriction, and spasm of gastrointestinal smooth muscle. Hydroxyzine exhibits antiemetic properties and is an effective anxiolytic. Hydroxyzine crosses the blood-brain barrier and produces an anticholinergic effect, as it blocks the action of the neurotransmitter acetylcholine in the central nervous system (brain) and produces sedation. 

Antihistamine piperazine derivatives are used to treat:

• Anxiety
• Pruritis (itching)
• Chronic urticaria (skin rash associated with food allergy)
• Preoperative sedation

Off-label use includes:

• Nausea and vomiting

Some of the side effects associated with antihistamine piperazine derivatives may include:

• Headache
• Dry mouth
• Drowsiness
• Tremors
• Skin rash and itching
• Anaphylaxis (life-threatening allergic reactions)

The information contained herein is not intended to cover all possible side effects, precautions, warnings, drug interactions, allergic reactions, or adverse effects. Check with your doctor or pharmacist to make sure these drugs do not cause any harm when you take them along with other medicines. Never stop taking your medication and never change your dose or frequency without consulting your doctor.

Generic and brand names of antihistamine piperazine derivatives include:

• Hydroxyzine
• Vistaril