Hydroxyzine
1 medicine
Hydroxyzine is an antihistamine used for itching, short-term anxiety, and sedation before procedures; it can prolong the heart's QT interval, so it should be avoided with other QT-prolonging medicines.
Key facts
- Hydroxyzine is an antihistamine that relieves itching and hives, eases short-term anxiety, and provides sedation before or after a procedure.
- It's taken as needed or short-term; effects begin within an hour and sedation can last several hours.
- It can prolong the heart's QT interval and raise the risk of a dangerous heart rhythm, so it should not be combined with other QT-prolonging medicines or used if you have a heart rhythm disorder.
- Seek urgent care for a fast, irregular heartbeat, fainting, or severe confusion.
What hydroxyzine treats
Hydroxyzine treats itching and hives from allergic skin reactions, short-term anxiety, and nausea, and it's used as a sedative before and after surgery. It's not intended for long-term daily anxiety treatment.
How hydroxyzine works
Hydroxyzine blocks histamine H1 receptors, reducing the itching, redness, and swelling that histamine causes during an allergic reaction. It also dampens activity in parts of the brain that govern alertness and anxiety, producing a calming, sedating effect.
Before you take it
- Avoid hydroxyzine if you have congenital long QT syndrome, uncorrected low potassium or magnesium, a slow heart rate, or porphyria.
- Tell your prescriber about any other QT-prolonging medicines, glaucoma, urinary retention, or liver disease.
- Avoid alcohol and other sedating medicines such as opioids, benzodiazepines, or sleep aids, since effects add up.
- Older adults are more sensitive to sedation and fall risk and usually need a lower dose.
Side effects
Common effects include drowsiness, dry mouth, dizziness, and blurred vision.
Stop and seek urgent medical care for any of these:
- A fast, irregular, or pounding heartbeat, or fainting.
- Difficulty breathing or swelling of the face, lips, or throat.
- Severe confusion, agitation, or hallucinations.
- A widespread rash or hives that spread quickly.
Safety essentials
- QT prolongation is the defining cardiac risk. Tell every prescriber about your hydroxyzine use, avoid combining it with other QT-prolonging drugs, and get any palpitations or fainting checked urgently.
- Don't drive or use machinery until you know how it affects you, and skip alcohol while taking it.
- Use the lowest effective dose for the shortest time needed, particularly if you're older or have heart or liver disease.
This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.