ZYRTEC® Allergy Relief Tablets Adults under 65 and children 6 years and older One 10 mg tablet once daily; do not take more than one 10 mg tablet in 24 hours. A 5 mg product may be appropriate for less severe symptoms. Adults 65 years and over Ask a doctor.
Cetirizine is generally very safe. Taking more than the usual dose is unlikely to harm you or your child. If you take an extra dose, you might get some of the common side effects. If this happens or you're concerned, contact your doctor.
ZYRTEC 10 mg film-coated tablets
Others may need to take 20 mg, e.g. larger people or those who find that 10 mg is not enough. The maximum recommended daily dose is 20 mg, do not exceed this dose, unless told to do so by your doctor.
Take 1 tablet every 12 hours; do not take more than 2 tablets in 24 hours.
Taking too much cetirizine (Zyrtec) or using more than one medication containing an antihistamine (including products used on the skin) can lead to an accidental overdose and cause serious side effects, such as seizures, hallucinations, or even death. To prevent an accidental overdose, read package labels carefully.
Children's Zyrtec (ages 2+) chewable tablets contain 2.5 mg of cetirizine per tablet. If you are under 65 years old, chew and swallow 2 to 4 tablets (5 mg to 10 mg) once daily. Don't take more than 4 tablets in 24 hours. If you're 65 or older, only take 2 tablets per day.
Adults under 65 and children 6 years and older One 10 mg tablet once daily; do not take more than one 10 mg tablet in 24 hours. A 5 mg product may be appropriate for less severe symptoms. Adults 65 years and over Ask a doctor. Consumers with liver or kidney disease Ask a doctor.
If a healthy adult takes only a slightly higher dose of antihistamine, such as accidentally taking two pills instead of one, their symptoms may not be serious, or they may not have any symptoms. However, a larger overdose, especially in children or older adults, may cause serious symptoms.
Why do antihistamines stop working? Antihistamines can stop working because your allergies might be getting worse or you might have immune system changes due to aging. You also might not be taking the medication as directed. If you take an antihistamine after being exposed to an allergy trigger, it won't work as well.
Cetirizine can be taken at any time of the day. In most people it is non-sedating, so they take it in the morning. However, a percentage of people do find it to be sedating so if it does make you drowsy it is best to take it in the evening. Cetirizine can be taken with or without food.
Drug class: Antihistamines
Medically reviewed by Drugs.com. Last updated on Mar 11, 2022. one 10 mg tablet once daily; do not take more than one 10 mg tablet in 24 hours.
Taking 10mg of Zyrtec is more effective than taking 5mg; taking 20mg appears not to provide any additional effect. Food has no effect on the overall absorption of Zyrtec; however, it may increase the time it takes for peak levels of Zyrtec to be reached in the blood.
It's not a great idea, but an isolated incident of taking two Zyrtec is unlikely to have major health effects. In fact, some doctors double the dose of Zyrtec for their patients with severe hives if a single pill isn't working.
Zyrtec. Zyrtec (cetirizine) is the strongest of the second-generation antihistamines, says Dr. Garcia-Ibáñez. And because there is less chance of toxicity with this medication, the dosage can be increased substantially, at the discretion of your doctor, he says.
Tell your doctor or pharmacist if you are taking other products that cause drowsiness such as opioid pain or cough relievers (such as codeine, hydrocodone), alcohol, marijuana (cannabis), drugs for sleep or anxiety (such as alprazolam, lorazepam, zolpidem), muscle relaxants (such as carisoprodol, cyclobenzaprine), or ...
Cetirizine reaches peak plasma concentration after approximately one hour. Its effects typically begin after 20 to 60 minutes and persist for at least 24 hours. Food does not affect the extent of exposure (AUC) of cetirizine, but the time to attain peak concentration is delayed by 1.7 hours.
Official answer. In general, an oral antihistamine tablet will start to work within 30 minutes and reach its maximum effect in about 2 hours. You will know when an antihistamine starts to work when it starts to relieve allergy symptoms, such as congestion, runny nose, itchy eyes or skin rash.
How fast does ZYRTEC® start working? ZYRTEC® begins to work at hour 1 on the first day you take it.
"When taken in the recommended doses, antihistamines can be taken daily.
For allergy sufferers with heart disease, medicines such as Allegra, Zyrtec or Claritin should be safe. However, medicines containing decongestants — including Allegra-D, Zyrtec-D and Claritin-D — could increase your blood pressure and heart rate or interfere with your heart medication.
“Zyrtec is found to be more potent, or stronger, in laboratory studies, compared with Claritin,” says Dr. Kung. “It also reaches a higher concentration in the skin, which can be more helpful for skin-related allergies. However, Zyrtec has a greater chance of making you sleepy while taking it.”
In overdose symptoms can include dizziness, tachycardia, headache drowsiness or agitation. While the current generation of lesser sedating antihistamines do not affect the QT interval at normal doses (unlike the previous generation of medicines), there are concerns there may be some effect in overdose.
Claritin and Zyrtec are popular over-the-counter antihistamines. Doctors consider them safe and effective treatments for minor allergies. Both are second-generation antihistamines. These cause less drowsiness than first-generation antihistamines.