A potent second-generation histamine H1 antagonist that is effective in the treatment of allergic rhinitis, chronic urticaria, and pollen-induced asthma. Unlike many traditional antihistamines, it does not cause drowsiness or anticholinergic side effects. .

Medicinal name:
  • 12 HR cetirizine hydrochloride 5 MG / Pseudoephedrine Hydrochloride 120 MG Extended Release Oral Tablet [Zyrtec-D]
  • Cetirizine hydrochloride 10 MG Oral Tablet [Zyrtec]
  • Cetirizine hydrochloride 10 MG Oral Capsule [Zyrtec]
  • Cetirizine hydrochloride 10 MG Disintegrating Oral Tablet [Zyrtec]
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Zyrtec - Pharmacology:

Zyrtec competes with histamine for binding at H1-receptor sites on the effector cell surface, resulting in suppression of histaminic edema, flare, and pruritus. The low incidence of sedation can be attributed to reduced penetration of cetirizine into the CNS as a result of the less lipophilic carboxyl group on the ethylamine side chain.

Zyrtec for patients

What is cetirizine?
- Zyrtec is an antihistamine. Zyrtec blocks the actions of the naturally occurring chemical histamine in the body. Zyrtec is less likely than some other antihistamines to cause side effects such as drowsiness and dizziness.
- Zyrtec is used to treat the symptoms of allergies such as sneezing; runny nose; itching, tearing, and redness of the eyes; and hives.
- Zyrtec may also be used for purposes other than those listed in this medication guide.

What should I discuss with my healthcare provider before taking cetirizine?
- Do not take cetirizine without first talking to your doctor if you have had an allergic reaction to it or to the medication hydroxyzine (Atarax, Vistaril).
- Before taking cetirizine, tell your doctor if you have kidney or liver disease. You may need a dosage adjustment or special monitoring during treatment.
- Zyrtec is in the FDA pregnancy category B. This means that it is not expected to be harmful to an unborn baby. Do not take cetirizine without first talking to your doctor if you are pregnant or could become pregnant during treatment.
- Zyrtec passes into breast milk and may affect a nursing baby. Do not take cetirizine without first talking to your doctor if you are breast-feeding a baby.
- If you are over 65 years of age, you may be more likely to experience side effects from cetirizine. Your doctor may prescribe a lower dose of this medication.

How should I take cetirizine?
- Take cetirizine exactly as directed by your doctor. If you do not understand these directions, ask your pharmacist, nurse, or doctor to explain them to you.
- Take the tablets with a full glass of water.
- Chew the chewable tablets thoroughly before swallowing.
- To ensure you get the correct dose, measure the liquid form of cetirizine with a dose-measuring spoon, cup, or dropper, not with a regular table spoon. If you do not have a dose-measuring device, ask your pharmacist where you can get one.
- Zyrtec can be taken with or without food.
- Store cetirizine at room temperature away from moisture and heat.

Zyrtec Interactions

Pharmacokinetic interaction studies with cetirizine in adults were conducted with pseudoephedrine, antipyrine, ketoconazole, erythromycin and azithromycin. No interactions were observed. In a multiple dose study of theophylline (400 mg once daily for 3 days) and cetirizine (20 mg once daily for 3 days), a 16% decrease in the clearance of cetirizine was observed. The disposition of theophylline was not altered by concomitant cetirizine administration.

Drug-Drug Interactions: No clinically significant drug interactions have been found with theophylline at a low dose, azithromycin, pseudoephedrine, ketoconazole, or erythromycin. There was a small decrease in the clearance of cetirizine caused by a 400-mg dose of theophylline; it is possible that larger theophylline doses could have a greater effect.

Zyrtec Contraindications

Zyrtec is contraindicated in those patients with a known hypersensitivity to it or any of its ingredients or hydroxyzine.

Manufacturers name:

  • Physicians Total Care, Inc
  • Bryant Ranch Prepack
  • McNeil Consumer Healthcare Div McNeil-PPC, Inc
  • McNeil Consumer Healthcare Division of McNeil-PPC, Inc

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