Yes, you can take cetirizine (Zyrtec) only when you need it if you have allergy symptoms once in a while. But if you have allergy symptoms on a daily basis, taking it regularly according to the manufacturer's directions might give you the most relief from your allergies.
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.
Cetirizine is unlikely to do you any harm if you take it for a long time. However it's best to take cetirizine only for as long as you need to. If you take it regularly over a long period there's a very small chance of severe itching if you stop treatment suddenly.
Antihistamines are a unique option for treating seasonal allergies. They work quickly to help get symptoms under control. But if taken every day, they can also help prevent symptoms from starting.
Taking antihistamines
If you're allergic to something that's often around, you may need longer treatment. Some people take antihistamines every day, but usually under medical guidance. If you find you're needing to take antihistamines long term, talk to your GP about this.
Allergists recommend long-acting, non-sedating antihistamines — ones that won't make you sleepy — for everyday use. Though you may know them by their brand names, the generic versions tackle the same problems: Cetirizine (Zyrtec®, Aller-Tec®, Wall-Zyr®).
There are some potential side effects and there are some cases where long-term antihistamine use can worsen urinary retention or narrow angle glaucoma.
However, Zyrtec does occasionally have some side effects, the most common of which are drowsiness, dizziness, fatigue, and headaches. There have been reports, through few studies, of withdrawal symptoms in people attempting to stop taking Zyrtec. These people report unbearable pruritus (itching) and/or hives.
When antihistamines block histamine, our appetite can increase. This, plus side effects like drowsiness, could lead to weight gain. Your risk of gaining weight from antihistamines may depend on many factors. But a healthy diet, physical activity, and other lifestyle factors can help you manage your risk.
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.
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.
Zyrtec Withdrawal: Severe Itching & Hives
This itching may begin as soon as 12 hours after the last dose of Zyrtec and can affect every part of the body. Some patients report itching so severe that they cannot control scratching and have caused sores all over their bodies.
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.
Long term use of some antihistamines may increase your risk of dementia. Diphenhydramine (Benadryl®) blocks the effects of a neurotransmitter called acetylcholine. This neurotransmitter is vital for memory and learning.
Cetirizine and levocetirizine have been linked to rare, isolated instances of clinically apparent acute liver injury.
Is Zyrtec safe for someone with kidney disease? Cetirizine (Zyrtec) is primarily eliminated through the kidney; however, it is also partially metabolized in the liver. Patients with renal dysfunction may be more susceptible to cetirizine side effects due to poor medication clearance.
Sandoz issued a voluntary recall of 1,023,430 units of Zyrtec (10 mg) capsules as a result of failed impurities and a specification being reported for impurity at the 21-month stability time point, according to an FDA Enforcement Report.
Some people report that if they stop such antihistamines suddenly, they can experience levocetirizine (Xyzal) and cetirizine (Zyrtec) withdrawal itching.
Adults and children 6 years and over:
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.
by Drugs.com
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.
Allergy shots, also known as subcutaneous immunotherapy (SCIT), are the most commonly used and most effective form of allergy immunotherapy. This is the only treatment available that actually changes the immune system , making it possible to prevent the development of new allergies and asthma .
The evidence presented does suggest, however, that patients on prolonged antihistamine therapy may develop clinical tolerance. When this is suspected the dose should be increased or the drug discontinued for a short perior (3 to 14 days) before resuming therapy.