Cetirizine dihydrochloride

Generic name: Cetirizine hydrochloride.
Chemical name:  [2- [4- [(4-chlorophenyl) phenylmethyl] -1- piperazinyl] ethoxy]acetic acid, dihydrochloride.
Cetirizine, a metabolite of hydroxyzine, is an antihistamine drug. Its main effects are achieved through selective inhibition of peripheral H1 receptors.
Cetirizine was rapidly absorbed with a time to maximum concentration of about 1 hour after oral administration of tablets or syrup formulation in adult volunteers.
Cetirizine hydrochloride syrup is indicated for the relief of symptoms associated with perennial allergic rhinitis due to allergens such as dust mites, animal dander and molds.
Cetirizine is a second generation drug.
Second generation antihistamines are developed to avoid or reduce the sedative effects of drug.
Second-generation antihistamines cross the blood–brain barrier to a much lower degree than the first-generation antihistamines. Their main benefit is they primarily affect peripheral histamine receptors and therefore are less sedating.

1. Generic name : Cetirizine hydrochloride. Chemical name:  [2- [4- [(4-chlorophenyl) phenylmethyl ] -1- piperazinyl ] ethoxy ]acetic acid, dihydrochloride. Cetirizine, a metabolite of  hydroxyzine , is an antihistamine drug. Its main effects are achieved through selective inhibition of peripheral H1 receptors. Cetirizine was rapidly absorbed with a time to maximum concentration of about 1 hour after oral administration of tablets or syrup formulation in adult volunteers. Cetirizine hydrochloride syrup is indicated for the relief of symptoms associated with perennial allergic rhinitis due to allergens such as dust mites, animal dander and molds . Cetirizine is a second generation drug. Second generation antihistamines are developed to avoid or reduce the sedative effects of drug. Second-generation antihistamines cross the blood–brain barrier to a much lower degree than the first-generation antihistamines. Their main benefit is they primarily affect peripheral histamine receptors and therefore are less sedating. Cetirizine hydrochloride

2. M ode of action of Allergen Mast cells generate mediators of inflammation which are stored in granules and secreted  on activation either by allergen crosslinking of membrane-bound IgE or through other stimuli. The H 1  receptor  is a histamine receptor belonging to the family of rhodopsin-like G-protein-coupled  receptors. This H1 receptor  is activated by the biogenic amine histamine. It is expressed in smooth muscles, on vascular endothelial cells, in the heart, and in the central nervous system.

3. Mode of action of Cetirizine

4. Mode of action of cetirizine

5. Side effects of cetirizine The most commonly reported side effects include somnolence, dizziness, and headache. Applies to cetirizine : oral solution, oral tablets and chewable tablets Side effects include: Adults and children ≥12 years of age: Somnolence, fatigue, dry mouth.  Insomnia  reported with cetirizine hydrochloride-pseudoephedrine hydrochloride fixed combination. Children 2–11 years of age:  Headache, pharyngitis, abdominal pain. Children 6 months to 2 years of age: Irritability, fussiness, insomnia, fatigue, malaise. Cetirizine is a second generation drug. It can cross blood brain barrier (BBB) and result in side effects like sleepiness or dizziness. But it is effective than first generation drugs. Now, third generation is most efficient because it can not cross BBB. i.e., Desloratadine . BS Chemistry Section Analytical Semester 8 th Group # 4 th Sheffer , A. L., & Samuels, L. L. (1990). Cetirizine: antiallergic therapy beyond traditional H1 antihistamines.  Journal of Allergy and Clinical Immunology ,  86 (6), 1040-1046. Bhatia, N. M., Ganbavale , S. K., Bhatia, M. S., More, H. N., & Kokil , S. U. (2008). RP-HPLC and spectrophotometric estimation of ambroxol hydrochloride and cetirizine hydrochloride in combined dosage form.  Indian journal of pharmaceutical sciences ,  70 (5), 603 . www.drugs.com www.webmed.com www.echo.co.uk