Description

Simple

A medication used to treat the symptoms of allergies such as runny nose, red and watery eyes, as well as itchiness.

Clinical

A selective Histamine-1 antagonist drug used in allergic rhinitis and chronic urticaria.

Overview

Cetirizine, also commonly known as _Zyrtec_, is an orally active second-generation histamine H1 antagonist proven effective in the treatment of various allergic symptoms, such as sneezing, coughing, nasal congestion, hives, and other symptoms [1], [2].

One of the most common uses for this drug is for a condition called _allergic rhinitis_. The prevalence of allergic rhinitis in the United States is about 15% according to physician diagnoses, and up to 30%, according to self-reported nasal symptoms. Allergic rhinitis is associated with multiple missed or unproductive days at work and school, problems with sleep, and other difficulties with day to day activities for many individuals [3]. Furthermore, some antihistamine agents that are used to treat this condition cause undesirable, sedating effects [Read more

Pharmacology

Indication

**Seasonal Allergic Rhinitis**: Indicated for the relief of symptoms associated with seasonal allergic rhinitis caused by allergens such as ragweed, grass and tree pollens in adults and children 2 years of age and above. Symptoms treated effectively include sneezing, rhinorrhea, nasal pruritus, ocul... Read more

Pharmacodynamic

**General effects and respiratory effects**

Cetirizine, the active metabolite of the piperazine H1-receptor antagonist hydroxyzine, minimizes or eliminates the symptoms of chronic idiopathic urticaria, perennial allergic rhinitis, seasonal allergic rhinitis, allergic asthma, physical u... Read more

Mechanism of action

Cetirizine, a metabolite of _hydroxyzine_, is an antihistamine drug. Its main effects are achieved through selective inhibition of peripheral H1 receptors. The antihistamine activity of cetirizine has been shown in a variety of animal and human models. _In vivo_ and _ex vivo_ animal models have sho... Read more

Absorption

Cetirizine was rapidly absorbed with a time to maximum concentration (Tmax) of about 1 hour after oral administration of tablets or syrup formulation in adult volunteers [FDA label]. Bioavailability was found to be similar between the tablet and syrup dosage forms. When healthy study volunteers were... Read more

Protein binding

The mean plasma protein binding of cetirizine is 93% [FDA label].

Volume of distribution

Apparent volume of distribution: 0.44 +/- 0.19 L/kg [ Read more

Clearance

Apparent total body clearance: approximately 53 mL/min [FDA label].Cetirizine is mainly eliminated by the kidneys [ Read more

Half life

Plasma elimination half-life is 8.3 hours [FDA label].

Route of elimination

Mainly eliminated in the urine [FDA label], [1].

Betwe... Read more

Toxicity

Oral LD50 (rat): 365 mg/kg; Intraperitoneal LDLO (mouse): 138 mg/kg; Oral TDLO (rat): 50 mg/kg; Oral TDLO (mouse): 0.1 mg/kg [MSDS].

**Carcinogenesis and mutagenesis**: In a 2-year carcinogenicity study in rats, cetirizine was not shown to be carcinogenic at dietary doses up to 20 mg/kg (approxi... Read more

Adverse Effects

Effect Regions Age Groups Incidences Evidence Type
Headache US
  • pediatric
  • Kind: experimental
    • Percent: 11.0-14.0%
  • Kind: placebo
    • Percent: 12.3%
  • Clinical Trial
    Pharyngitis US
    • pediatric
  • Kind: experimental
    • Percent: 2.8-6.2%
  • Kind: placebo
    • Percent: 2.9%
  • Clinical Trial
    Fatigue US
  • Kind: experimental
    • Percent: 5.9
  • Clinical Trial
    Abdominal Pain US
    • pediatric
  • Kind: experimental
    • Percent: 4.4-5.6%
  • Kind: placebo
    • Percent: 1.9%
  • Clinical Trial
    Dry Mouth US
  • Kind: experimental
    • Percent: 5
  • Clinical Trial
    Cough US
    • pediatric
  • Kind: experimental
    • Percent: 2.8-4.4%
  • Kind: placebo
    • Percent: 3.9%
  • Clinical Trial
    Somnolence US
    • pediatric
  • Kind: experimental
    • Percent: 1.2-4.2%
  • Kind: placebo
    • Percent: 1.3%
  • Clinical Trial
    Epistaxis US
    • pediatric
  • Kind: experimental
    • Percent: 1.9-3.7%
  • Kind: placebo
    • Percent: 2.9%
  • Clinical Trial
    Diarrhea US
    • pediatric
  • Kind: experimental
    • Percent: 1.9-3.1%
  • Kind: placebo
    • Percent: 1.3%
  • Clinical Trial
    Bronchospasm US
    • pediatric
  • Kind: experimental
    • Percent: 1.9-3.1%
  • Kind: placebo
    • Percent: 1.9%
  • Clinical Trial
    Nausea US
    • pediatric
  • Kind: experimental
    • Percent: 1.9-2.8%
  • Kind: placebo
    • Percent: 1.9%
  • Clinical Trial
    Vomiting US
    • pediatric
  • Kind: experimental
    • Percent: 2.3-2.5%
  • Kind: placebo
    • Percent: 1.0%
  • Clinical Trial
    Dizziness US
  • Kind: experimental
    • Percent: 2
  • Dizziness US
  • Kind: experimental
    • Percent: 2
  • Clinical Trial
    Photosensitivity reaction US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Maculopapular rash US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Increases sweating US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Pruritus US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Toxic photosensitivity reaction US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Seborrhea US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Rash US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Purpura US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Urticaria US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Skin nodule US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Skin disorder US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Angioedema US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Acne US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Alopecia US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Dermatitis US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Dry Skin US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Bullous eruption US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Erythematous rash US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Eczema US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Hypertrichosis US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Furunculosis US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Hyperkeratosis US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Back Pain US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Asthenia US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Chest Pain US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Enlarged abdomen US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Fever US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Facial edema US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Generalized edema US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Hot Flashes US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Leg edema US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Increased weight US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Malaise US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Parosmia US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Taste loss US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial
    Taste perversion US
  • Kind: experimental
    • Percent: <2%
  • Clinical Trial

    Contraindications

    • Route:
      • Oral
    • Hypersensitivity:
      • true
      • hydroxyzine
    • Regions: US
    • Route:
      • Oral
    • Hypersensitivity:
      • true
    • Regions: US

    Food Interactions

    Avoid alcohol.

    Take with or without food. The absorption is unaffected by food.