How Zyrtec (Cetirizine) Works for Hives, How to Use It and What to Watch For
Zyrtec (cetirizine) is one of the most commonly used antihistamines for hives, and it is widely used by doctors as a first treatment. It is available over the counter, including a version labeled specifically for hives. This guide covers how Zyrtec works for hives, how to take it, and the side effects and cautions to know about.
Does Zyrtec Help With Hives?
Yes. Zyrtec is a non-sedating (second-generation) antihistamine that blocks histamine, the chemical responsible for itching and swelling in hives. It reduces hives and relieves itching, and it is one of the best-studied antihistamines for this purpose. As with all antihistamines, the label notes that it does not prevent hives from occurring.
Zyrtec Hives Relief
Zyrtec Hives Relief tablets contain 10 mg of cetirizine and are labeled to reduce hives and relieve itching due to hives. The active ingredient is the same as in Zyrtec allergy products, which are labeled for hay fever and other allergy symptoms. Check the label to confirm the product you buy is indicated for hives.
How to Take Zyrtec for Hives
Always follow your product’s label. For Zyrtec Hives Relief 10 mg tablets, the label directs:
- Ages 6 and older: one 10 mg tablet once daily, and no more than one 10 mg tablet in 24 hours.
- Under 6, or ages 65 and older: ask a doctor first.
- People with liver or kidney disease: ask a doctor first.
How Quickly Does Zyrtec Work?
Many people feel relief within about an hour, with effects lasting up to 24 hours. For chronic hives, daily use over several days or weeks is usually needed to see the full benefit.
Zyrtec Side Effects
Cetirizine is considered non-sedating, but it makes some people sleepy, a little more often than loratadine or fexofenadine. Other possible side effects include dry mouth, fatigue and headache. If it makes you drowsy:
- Try taking it in the evening.
- Avoid alcohol, sedatives and tranquilizers, which can increase drowsiness.
- Use caution when driving or operating machinery until you know how it affects you.
Zyrtec vs. Other Hives Antihistamines
Zyrtec is closely related to Xyzal (levocetirizine) and is in the same class as Allegra and Claritin. If Zyrtec makes you too sleepy, or does not control your hives, a doctor may suggest switching. See the best antihistamine for hives and Allegra for hives for comparisons.
When to Stop Zyrtec and See a Doctor
- You have an allergic reaction to Zyrtec
- Your symptoms do not improve after 3 days
- Your hives last more than 6 weeks (see how long hives last)
- Your hives are an unusual color, look bruised or blistered, or do not itch
At the Hives Treatment Center in San Francisco, Dr. Tiffany Young offers online and in-person consultations for people whose hives need more than over-the-counter medicine.
Emergency Warning Signs
Call 911 or go to the nearest emergency room right away if hives come with trouble breathing, wheezing, tightness in the throat, swelling of the tongue or lips, dizziness or fainting. These can be signs of anaphylaxis, a severe allergic reaction that needs immediate treatment.
Zyrtec is not a substitute for a prescribed epinephrine injector.
Zyrtec for Hives in Children and Pregnancy
Dosing for children depends on age, so follow the age directions on the label, and ask a pediatrician for children under 6. If you are pregnant or breastfeeding, ask your doctor before taking Zyrtec or any other medicine.
Frequently Asked Questions
Can I take Zyrtec every day for hives?
Doctors often recommend daily non-sedating antihistamines for chronic hives. Over-the-counter labels advise asking a doctor if hives last longer than 6 weeks.
Is Zyrtec or Allegra better for hives?
Both are effective. Zyrtec may work a little faster for some people but can cause more drowsiness, while Allegra is less likely to cause sleepiness. The best one is the one that works for you.
Can I take Zyrtec with Pepcid?
Doctors sometimes combine an antihistamine with an H2 blocker like famotidine for stubborn hives, but only under medical direction.
If Zyrtec Is Not Enough
Hives that keep breaking through an antihistamine are common and treatable. Visit our hives treatment page to see the latest treatment options for your outbreak.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis or treatment. If you think you are having a medical emergency, call 911.
