Cetirizine

  • (RS ) -2 - ( (4 - ( 4-chlorophenyl) - phenylmethyl) - 1 - piperazinyl) ethoxyacetic acid
  • Rac -2-( (4 - ( 4-chlorophenyl) - phenylmethyl) - 1 - piperazinyl) ethoxyacetic acid
  • (±) -2 - ( (4 - ( 4-chlorophenyl) - phenylmethyl) - 1 - piperazinyl) ethoxyacetic acid
  • DL-2- ( (4 - ( 4-chlorophenyl) - phenylmethyl) - 1 - piperazinyl) ethoxyacetic acid
  • C21H25ClN2O3 [ cetirizine ]
  • C21H25ClN2O3 · 2 HCl [ cetirizine dihydrochloride ]
  • 83881-51-0 [( RS)- cetirizine ]
  • 83881-52-1 [( RS)- cetirizine dihydrochloride · ]
  • 130018-77-8 [(R) - cetirizine ]
  • 130018-87-0 [(R ) cetirizine dihydrochloride · ]

R06AE07

Antihistamines of ethylenediamine - type

  • 388.89 g · mol -1 [( RS)- cetirizine ]
  • 461.81 g · mol -1 [( RS)- cetirizine dihydrochloride · ]

Attention

365 mg · kg -1 ( LD50, Rat, oral, dihydrochloride)

Template: Infobox chemical / molecular formula search available

Cetirizine is a drug selected from the group of the second-generation antihistamines, which is used for relieving symptoms of allergic diseases. The substance is from hydroxyzine, a first-generation antihistamine, developed. Chemically counts cetirizine on derivatives of ethylenediamine and the piperazine.

Application

Cetirizine is used to relieve the symptoms of allergies, eczema, hives and itching and other allergic skin reactions. Furthermore Cetirizine may be taken for hayfever and allergic -related conjunctivitis. Among the newer H1 antihistamines cetirizine, loratadine, in addition to the substance, probably the most widely used anti-allergic tablets.

Mechanism of action

The effect of histamine on the H1 receptor is interrupted. Histamine causes the typical hay fever symptoms such as watery eyes and nasal congestion, but also itching of the skin. The second-generation antihistamines have the advantage that very little active substance passes into the central nervous system because the drug molecule exists as a zwitterion under physiological conditions and the blood -brain barrier as well as can not be overcome. Compared to first-generation antihistamines sedative side effects such as fatigue appear less frequently.

Cetirizine and levocetirizine to be metabolized to 30 % of the liver ( metabolized ) and 70% is excreted via the kidney ( renal ). The maximum plasma concentrations are achieved after 40-60 min and the plasma half -life is approximately 9-10 hours.

Side effects

In part (about 1 in 100 patients) reported fatigue, headache, drowsiness or dry mouth. In addition, cetirizine is as loratadine and azelastine suspected in certain predisposition to trigger cardiac arrhythmias under certain circumstances - but not as often as terfenadine, where this side effect is known and proven, and therefore is also available on prescription.

Interactions

At therapeutic doses of cetirizine were associated with the intake of alcohol - at a plasma concentration of 0.5 grams / liter ( 0.5 " per thousand ", a glass of wine corresponding to approximately ) - no clinically significant drug interactions.

Due to the pharmacokinetic, pharmacodynamic and tolerance profile of cetirizine, no interactions with this antihistamine can be expected. In fact, neither pharmacodynamic nor significant pharmacokinetic interactions were reported in studies carried out interaction, especially with pseudoephedrine and theophylline (400 mg / day). The extent of absorption of cetirizine is not reduced with food, although the rate of absorption is reduced.

Stereochemistry

Cetirizine is a 1:1 mixture of the (R ) - (- )-enantiomer and (S ) - ( )- enantiomer ( racemate). Through a resolution can be specifically the active ( R) - ( -)- enantiomer ( eutomer ) of cetirizine win, that is referred to as levocetirizine. The significance of the enantiomeric purity of the active compounds synthetically produced was given by the development of levocetirizine attention, for the two enantiomers of a chiral drug almost always show a different pharmacology and pharmacokinetics. This was previously often ignored due to ignorance of stereochemical relationships.

A superiority over the parent drug cetirizine in terms of efficacy, however, can prove for Levocetirizine due to the lack of comparative studies so far not unique, even if some studies suggest.

Trade names

Cerchio (IT), Cerzin (CH), Cetallerg (CH), Cet eco ( CH), Ceterifug (D), Cetiderm (D), CetiLich (D), Ceti -grooves (D), Cetirigamma (D), Cetrin ( CH), Cetryn (TR ), Helvecin (CH), histamine -X ( CH), RatioAllerg (A), Reactine (D), Tirizin (A), Triofan allergy ( CH), Zyrtec (D, A, CH), numerous generics (D)

Reactine Duo (D)

CAS registry number PubChem Anatomical Therapeutic Chemical Classification System DrugBank Dangerous Substances Directive (67/548/EEC) Active ingredient Lightheadedness Xerostomia Pharmacodynamics Digital Object Identifier European Journal of Clinical Pharmacology
173973
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