Histamine plays a role in our appetite. When antihistamines block histamine, our appetite can increase. This, plus side effects like drowsiness, could lead to weight gain.
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. If you've been taking cetirizine every day for a long time, talk to your doctor before stopping it.
Difficulty sleeping (insomnia). Convulsions. Fluid retention (oedema). Weight gain.
If you need an antihistamine for frequent allergy symptoms, however, the best choice is Claritin because it does not cross into the brain and has less effect on appetite and sedation.
The most commonly reported side effects include somnolence, dizziness, and headache. Use these dosage charts for infants and children under 12 years old: Zyrtec Dosage Charts (Infants & Children)
Do not use with any other antihistamines applied to the skin (such as diphenhydramine cream, ointment, spray) because increased side effects may occur. Cetirizine is very similar to hydroxyzine and levocetirizine. Do not use these medications while using cetirizine.
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.
Is it safe to use antihistamines every day? In general, most of the available over-the-counter antihistamines are safe for long-term use. There are some potential side effects and there are some cases where long-term antihistamine use can worsen urinary retention or narrow angle glaucoma.
H1 receptor antihistamines such as cetirizine, fexofenadine, and desloratadine are among the most commonly prescribed medications for the treatment of allergies and have been shown to stimulate appetite and weight gain as side effects of treatment (6).
What's the best time of day to take ZYRTEC®? Any time of day works. And ZYRTEC® will continue to work for 24 hours.
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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.
In general, anti-histamines do not cause kidney problems. Some, such as diphenhydramine (Benadryl) can cause retention of urine in your bladder. Others such as Claritin and Zyrtec are generally very safe.
While there's no set timeline for when someone should stop taking an antihistamine, one should speak to a doctor or drug rehabilitation specialist if they feel like they have become addicted to your antihistamine. The severity and length of an antihistamine withdrawal will depend on the specific drug.
Many allergy medications, such as Zyrtec, are recommended every 24 hours. By taking the medication before bedtime you're more likely to get through the night without the active ingredients wearing off or becoming less effective closer to the end of the 24 hour period.
Antihistamines
Antihistamines are known to cause extreme drowsiness; however, in certain people, they can cause insomnia, excitability, anxiety, restlessness, and a rapid heart rate.
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®). Fexofenadine (Allegra®, Aller-ease®, Aller-Fex®, Wal-Fex®).
Excessive antihistamine use has also been shown to increase mental complications such as dementia and short-term memory loss, as these drugs prevent the neurotransmitter acetylcholine (which helps with memory and learning) from functioning as well, potentially leading to memory impairment.
These common side effects include sedation, impaired motor function, dizziness, dry mouth and throat, blurred vision, urinary retention and constipation. Antihistamines can worsen urinary retention and narrow angle glaucoma. The antihistamines rarely cause liver injury.
In general, wean gradually by 25-50% of the daily dose every 1-4 weeks. If reason for deprescribing is serious adverse effects, wean faster or cease immediately. Provide advice to patient/carer on self-monitoring and what to do if symptoms re-occur.
Can antihistamines cause depression? One study of 92 people with chronic itchiness saw that patients who took the antihistamines cetirizine and hydroxyzine reported an increase in depression and anxiety.
The verdict: Food allergies don't cause weight gain
“However, if you're eating food that you're sensitive to, it could lead to bloating and stomach discomfort – and you're less likely to exercise if you're not feeling well.”
Mechanism of Injury. The cause of acute liver injury from cetirizine is not known. It is metabolized by the liver and a toxic metabolite may account for idiosyncratic injury.
First generation antihistamines, while very effective at controlling symptoms, are often associated with symptoms in older adults such as anxiety, confusion, sedation, blurred vision, reduced mental alertness, urinary retention and constipation.
If your allergy symptoms include sinus congestion, it may be worth considering Claritin-D (loratadine/pseudoephedrine], Allegra-D (fexofenadine/pseudoephedrine), or Zyrtec-D (cetirizine/pseudoephedrine).