What Is the Difference Between Loratadine and Cetirizine?

Cetirizine (Cetirizine) is an anti-allergic drug, also known as deminidine, styridine, xantamine, Xie Di, CETIN or CETY. It is a second-generation H1 antihistamine, which is a long-acting Selective oral potent anti-allergic drug. For seasonal or perennial allergic rhinitis, urticaria caused by allergens, and itching of the skin. In China, starting from January 11, 2008, cetirizine hydrochloride was converted from prescription to over-the-counter. It is marketed by GlaxoSmithKline as an over-the-counter drug under the name Chi Min Su in Hong Kong.

Drug Name: Cetirizine
Alias: Setzen
Whether prescription drugs: Non-prescription drugs
Main indications: Anti-allergy

Adverse reactions: Slight and transient
Main medication contraindications: Patients who are allergic to hydroxyzine and severely impaired renal function
Drug type: Antiallergic drugs
Ingredients: Cetirizine

Cetirizine Basic Information

Chinese name: ciltirizine

Chinese alias: Setezan

English name: cetirizine

English alias: Zirtek; Cetirizine; Reactine; P-071; vidix;

CAS number: 83881-51-0

Molecular formula: C ₂₁ H ₂₅ ClN ₂ O ₃

Chemical structure:

Molecular weight: 388.888800

Exact mass: 388.15500

PSA: 53.01000

LogP: 3.02400

Cetirizine physical and chemical properties

Appearance and properties: white to off-white crystalline powder

Density: 1.237 g / cm ³

Melting point: 110-115 ° C

Boiling point: 542.1ºC at 760 mmHg

Flash point: 281.6ºC

Water solubility: 101 mg / L ^[1]

Cetirizine molecular structure data

1. Molar refractive index: 105.94

2. Molar volume (cm3 / mol): 314.2

3. Isotonic specific volume (90.2K): 838.8

4. Surface tension (dyne / cm): 50.7

5. Polarizability (10-24cm3): 41.99

Cetirizine Computational Chemical Data

1. Hydrophobic parameter calculation reference value (XlogP): None

2.Number of hydrogen-bonded donors: 1

3.Number of hydrogen bond acceptors: 5

4.Number of rotatable chemical bonds: 8

5.Number of tautomers: none

6. Topological molecular polar surface area 53

7.Number of heavy atoms: 27

8.Surface charge: 0

9.Complexity: 443

10.Number of isotope atoms: 0

11. Determine the number of atomic stereocenters: 0

12. Uncertain number of atomic stereocenters: 1

13. Determine the number of chemical bond stereocenters: 0

14. Uncertain number of chemical bond stereocenters: 0

15. Number of covalent bond units: 1 ^[2]

Cetirizine

1 Cetirizine 1, classification

Respiratory Drugs> Asthma Drugs> Airway Dilators

2 Cetirizine 2, dosage form

Tablet: 10mg.

3 Cetirizine 3, pharmacological effects of cetirizine

Cetirizine has no effect on mast cells in the allergen immunity test, but inhibits the response of neutrophils and platelets. The single dose of clothing was 20mg, and the patient had no severe drowsiness and cognitive behavior changes. The sedative effect of cetirizine 10mg is similar to placebo, loratadine 10mg, and terfenadine 120mg, but it is significantly weaker than oxalimet 30mg or ketotifen 1mg. Cetirizine 5 to 20 mg was taken orally or divided into multiple doses, and there was no damage to psychomotor behavior; however, in a single test, a single dose of 10 mg of cetirizine caused significant damage to driving behavior.

4 Pharmacokinetics of Cetirizine 4, Cetirizine

Healthy adults reached peak plasma concentrations (257 and 580 g / L) within 1 hour after taking 10 to 20 mg of cetirizine. Food delays the rate of absorption but does not affect the extent of absorption. The effect can be maintained for 24h. Cetirizine is basically not metabolized in the body, and most of it is excreted in its original form by urine, stool, sweat, emulsion, and the like. Transurethral excretion rate accounts for 70%, and stools account for 10%. All excreted within 2 days. The t1 / 2 in adults is 7.4 to 11 hours, and the t1 / 2 in children is 6.2 hours. It is not easy to penetrate the blood-cerebrospinal fluid barrier.

5 Indications for Cetirizine 5, Cetirizine

For the treatment of seasonal allergic rhinitis (allergic rhinitis, hay fever). It has good curative effect on acute and chronic skin, eye, respiratory tract and other allergic reactions. It is often used for allergic rhinitis, dermatitis, conjunctivitis, asthma, urticaria and so on.

6 Cetirizine 6, contraindications for cetirizine

1). Allergic to cetirizine, severe liver disease, severe heart disease, arrhythmia, abnormal electrocardiogram (obvious or suspicious prolongation of QT interval), or hypokalemia are contraindicated.

2). Banned during pregnancy, especially in the first 3 months and lactation.

7 Cetirizine 7, precautions

1) Not recommended for children under 12 years of age.

2). Renal dysfunction should be reduced appropriately.

3). Overdose use can cause fatal arrhythmias.

4). The amount of medicine for driving, working at high altitude, diving, etc. should be strictly controlled within a safe range.

5). Patients with severe liver and kidney dysfunction, patients who drink alcohol and often take sleeping pills should be used with caution.

8 Cetirizine 8, adverse reactions of cetirizine

The most common adverse reactions were sedation, headache, dry mouth, fatigue, and nausea. The incidence of sedative effects was similar to placebo, astemizole, loratadine, or terfenadine. Cetirizine 10 mg per day appears to have a stronger sedative effect than 10 mg per day of loratadine, 120 mg per day of terfenadine, or placebo. The sedative effect produced by 5 to 20 mg per day is much weaker than that of 25 to 75 mg per day of hydroxyzine. Hepatic dysfunction caused by cetirizine resolves spontaneously and is not common.

9 Cetirizine 9, dosage and dosage of Cetirizine

1). 10mg each time, once a day.

2). Children 6 to 12 years old take 5 mg once a day.

3). Children under 6 years old, 0.2mg / kg per day.

10 Cetirizine 10, interactions of Cetirizine and other drugs

1). Cannot be used at the same time with imidazole antifungal drugs and macrolide antibiotics (such as erythromycin, xanthomycin, clarithromycin or josamycin).

2). Attention should be paid to the simultaneous use of cimetidine, cyclosporine and heartache. Ethanol and sleeping pills can strengthen the central inhibitory effect of cetirizine.

11 Cetirizine 11, drug evaluation

The inhibitory effects of cetirizine 10 mg with terfenadine 120 mg, cetirizine 10 mg, loratadine 10 mg, and placebo on the formation of rubella and skin flushing were compared. The results show that mizolastine is more effective than loratadine. Eight double-blind, placebo-controlled volunteer studies using standard tests have shown that cetirizine has less impact on driving behavior than newer antihistamines. When 1-2 times higher than the recommended dose, cetirizine shows only a low level of sedation. Other clinical trials have shown that cetirizine has no potential pharmaceutical interaction with ethanol. In 16 male healthy volunteer experiments (10 mg per day). No effect of cetirizine on skill manipulation and memory was found. In multiple randomized double-blind clinical studies, the efficacy of cetirizine 5-20 mg per day on seasonal and long-term allergic rhinitis and chronic spontaneous urticaria has been confirmed. Cetirizine tends to reduce some syndromes of mild allergic asthma at 10 to 30 mg per day; effective at some physical urticaria at 10 to 30 mg / kg per day; moderate to 10 to 40 mg per day Severe atopic dermatitis syndrome; 10 mg daily relieves mosquito bites and causes local reactions. For seasonal allergic rhinitis, cetirizine 5 mg, 10 mg, or 20 mg daily relieves the effect of the syndrome, at least with 10 mg daily for astemizole, 10 mg daily for loratadine, 60 mg daily for terfenadine (twice a day) or 120mg per day is similar; for perennial allergic rhinitis, the effect is at least similar to astemizole 10 mg per day, ketotifen 2 mg per day or terfenadine 120 mg per day; for chronic spontaneous urticaria, the effect is at least as long as asmidazole 10 mg per day, hydroxyzine 25 to 75 mg per day or terfenadine 120 mg per day; for mild allergic asthma or atopic dermatitis, its efficacy is similar to 60 mg (twice) terfenadine per day; cetirizine 5 mg per day Or 10 mg is also effective for children with rhinitis ( 12 years old); 5 to 15 mg (twice) daily reduces the number of children with mild asthma. ^[3]