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.
Adults and children 6 years and older Chew and swallow 2 tablet (10 mg) once daily; do not take more than 1 tablet (10 mg) in 24 hours. A 5 mg product may be appropriate for less severe symptoms.
Don't take more than 1 tablet in 24 hours. 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.
Toxic doses of antihistamines may happen when a person takes 3 to 5 times the normal amount. No matter how much a person overdoses, they should seek medical help or call a poison control center.
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.
Overdose Signs
Overdose symptoms may include severe drowsiness, vision problems, agitation, fast heartbeats, stomach pain, nausea, vomiting, trouble walking, trouble swallowing or speaking.
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.
It's natural to worry if you realize you've accidently doubled your dose, but in most cases, you won't need to do anything if you mistakenly take two pills. Even children usually don't need treatment after a double dose. Just manage any symptoms you or your child has.
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.
Take 1 tablet every 12 hours; do not take more than 2 tablets in 24 hours.
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.
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.
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.
Any time of day works. And ZYRTEC® will continue to work for 24 hours.
The recommended initial dose of ZYRTEC is 5 mg or 10 mg per day in adults and children 12 years and older, depending on symptom severity. Most patients in clinical trials started at 10 mg. ZYRTEC is given as a single daily dose. The time of administration may be varied to suit individual patient needs.
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.
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The elimination half-life of Zyrtec is between 8 to 9 hours. It takes approximately 5.5 x elimination half-life for a medicine to be cleared from your system. For Zyrtec this is 5.5 x 9 hours which is about 2 days.
The most common dose contains 25 mg of diphenhydramine in each tablet or capsule. This is the formulation we'll be discussing here. The recommended adult Benadryl dosage for allergies is 1 to 2 tablets or capsules by mouth every 4 to 6 hours as needed. You shouldn't take more than 6 doses (300 mg) in a 24-hour period.
Medically reviewed by Drugs.com. Last updated on Oct 18, 2021. take 1 tablet every 12 hours; do not take more than 2 tablets in 24 hours.
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 ...
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.
It's generally safe to take the newer generation of antihistamines daily if you have year-round allergy symptoms. But make sure to avoid anything that has a "D" in its brand name, which stands for decongestants. Long-term use of decongestants will worsen your allergy symptoms.
Cetirizine and levocetirizine use are not generally associated with liver enzyme elevations, but have been linked to rare instances of clinically apparent liver injury.