Zyrtec is an antihistamine that reduces the effects of natural chemical histamine in the body. Histamine can produce symptoms of sneezing, itching, watery eyes, and runny nose. Zyrtec is used in adults and children to treat cold or allergy symptoms such as sneezing, itching, watery eyes, or runny nose.
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.
Antihistamines block the effects of a substance called histamine in your body. Histamine is normally released when your body detects something harmful, such as an infection. It causes blood vessels to expand and the skin to swell, which helps protect the body.
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.
Cetirizine does not influence the immune response.
Conclusion: Our findings indicate that sedating first-generation H1R antihistamines and H2R blockers might impair innate immune responses to bacteria and that these drugs should be used with caution in patients with severe bacterial infections.
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.
Is it safe to take Zyrtec every day? Yep. "When taken in the recommended doses, antihistamines can be taken daily. This is especially true with Zyrtec, since it doesn't show decreasing effectiveness if used daily," says Sima Patel, MD, an allergist at New York Allergy & Sinus Centers.
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.
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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.
Feeling drowsy or sleepy is one of the most common antihistamine side effects, especially in regard to first-generation antihistamines.
Hypertension, cardiovascular disease, urinary retention, increased ocular pressure are relative contraindications to the use of antihistamines.
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. I recommend that you always discuss this with your physician.
What happens if I overdose on Zyrtec (Cetirizine (Oral/Injection))? Overdose symptoms may include extreme drowsiness, vision problems, agitation, feeling restless and then drowsy or tired, fast heartbeats, stomach pain, nausea, vomiting, trouble walking, or trouble swallowing or speaking.
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.
Claritin and Zyrtec are effective and safe for most people with minor allergies.
Taking too much antihistamine can lead to adverse side effects and a potential antihistamine overdose. Antihistamines are a class of medication that treat allergy symptoms, such as sneezing, runny nose, and itching. As with any medication, taking too much can be harmful.
Antihistamines
Antihistamines are known to cause extreme drowsiness; however, in certain people, they can cause insomnia, excitability, anxiety, restlessness, and a rapid heart rate.
Some medications for treating allergies, like Zyrtec (cetirizine) and Allegra (fexofenadine) last 24 hours and don't need to be taken at night. But if you're combating allergy symptoms with a different antihistamine first thing in the morning, keep in mind that its effects will only last six to eight hours.
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.
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.
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.
Flonase and Zyrtec belong to different drug classes. Flonase is a corticosteroid and Zyrtec is an antihistamine.
The Journal of Clinical Sleep Medicine in its guidelines for sleep medications does not recommend the use of antihistamines for chronic insomnia. Sedating antihistamines can lead to dry mouth, constipation, retention of urine in the bladder, blurred vision and a drop of blood pressure upon standing.