Knowra Hydroxyzine Hydroxyzine Hydroxyzine is a first-generation antihistamine used to relieve itching and, in some settings, anxiety, nausea, and tension. It can cause drowsiness because it also blocks central histamine receptors.
Histamine H1 receptor : A receptor through which histamine promotes allergic symptoms and wakefulness. Hydroxyzine blocks this receptor to reduce itching and can promote drowsiness.
Pruritus : An unpleasant sensation that creates the urge to scratch. Relief of itching is a principal use of hydroxyzine.
Cetirizine : A second-generation antihistamine used mainly for allergic rhinitis and hives. It is generally less sedating than hydroxyzine and is commonly chosen for daytime allergy relief.
Anticholinergic burden : The cumulative effects of medications that block acetylcholine signaling, especially on cognition and bodily functions. Hydroxyzine can add to this burden, particularly when combined with other anticholinergic drugs.
Antihistamine : A drug that reduces effects of histamine by blocking or otherwise modifying histamine receptors. Hydroxyzine belongs to this drug family, whose members differ in sedation and selectivity.
Urticaria : A skin reaction marked by raised, often itchy wheals known as hives. Blocking histamine can relieve itching associated with hives.
Diphenhydramine : A first-generation antihistamine used for allergies, itching, and occasional sleep support. Like hydroxyzine, it can cause sedation and anticholinergic effects, but has different uses and dosing.
Torsades de pointes : A potentially life-threatening ventricular arrhythmia associated with prolonged QT intervals. This rare rhythm complication is a concern when hydroxyzine prolongs QT, especially alongside other risk factors.
Blood–brain barrier : A selective interface that regulates movement of substances from blood into the brain. Hydroxyzine enters the brain, helping explain its sedating effects.
Anxiety : A state of apprehension or worry that may include physical symptoms and impair daily functioning. Hydroxyzine is prescribed for some anxiety symptoms, usually as a short-term option.
Show all 22