In dermatology, cetirizine has proven to be effective in the treatment of various forms of urticaria and it reduces the pruritus of atopic eczema. For these conditions, frequently doses higher than 10 mg (up to 40 mg) are recommended to achieve the best benefit.
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.
The maximum recommended daily dose is 20 mg, do not exceed this dose, unless told to do so by your doctor. The usual dose of ZYRTEC oral solution is 10 mL, once a day. In children over 6 years of age, the daily dose of 10 mg is given as a single or divided dose.
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.
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.
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.
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.
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.
Cetirizine is an antihistamine used to relieve allergy symptoms such as watery eyes, runny nose, itching eyes/nose, sneezing, hives, and itching. It works by blocking a certain natural substance (histamine) that your body makes during an allergic reaction.
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.
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.
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 ...
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.
For adults and children over 12 years of age, the maximum dosage is 300 mg each day. For children ages 6 to 12 years, the maximum is 150 mg each day. Adults or children should not apply Benadryl products, such as the cream, gel, and spray, to their skin more than four times per day.
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.
Myth #11: You can build up a tolerance to antihistamines through continuous use. “There is no scientific evidence that you can develop a tolerance to oral antihistamine pills, such as Allegra, Zyrtec and Claritin,” Wierzbicki clears up.
For relief of symptoms from seasonal or yearly allergies: Adults and children 12 years of age and older—Take one tablet two times a day with or without food. Children 4 to 12 years of age—Use and dose must be determined by your doctor. Children and infants up to 4 years of age—Use is not recommended .
Can I take 2 allergy pills a day? It is important to take allergy pills and antihistamines as directed. If your allergy medications do not provide enough relief from your symptoms, do not take additional doses. Instead, reach out to your doctor to find a more effective allergy treatment plan.
According to David Shih, EVP of strategy and former chief medical officer at CityMD, I am probably fine. Because antihistamines like Claritin and Zyrtec are now available over the counter, we can trust that they're generally safe for longterm use, says Shih.
One study has reported a more serious long-term effect, a 3.5-fold increase in the risk of gliomas, a common type of brain tumor in patients with long-term antihistamine use for allergic conditions.
Benadryl, Claritin, and Zyrtec are likely cleared from your body about 2 days after your last dose. But Claritin and Zyrtec may have residual effects for 1 to 4 days after stopping daily use.