Loratadine

  • IUPAC: 4 - ( 8-chloro- 5 ,6 -dihydro- 11H -benzo [ 5,6] cyclohepta [1,2-b ] pyridin- 11 -ylidene) piperidine-1- carboxylic acid ethyl ester
  • Latin: Loratadinum

R06AX13

White to almost white polymorphic crystalline powder

Systemic antihistamines

Antagonist at histamine H1 receptors

134-136 ° C

  • Practically insoluble in water ( 0.011 mg · l-1 at 25 ° C)
  • Slightly soluble in acetone and methanol

> 5 g · kg -1 ( LD50, rat, oral)

Template: Infobox chemical / molecular formula search available

Loratadine is a drug from the group of antihistamines, which is used for the relief of allergies and atopic dermatitis ( eczema ). It was introduced in Germany in 1989 and is no longer available on prescription since 1994. In Germany finished product are available with loratadine as a tablet or effervescent tablet in the U.S. and UK, there are additional juice.

Mechanism of Action

Loratadine is an antihistamine H1 of the second generation. It blocks the specific binding sites for histamine at the histamine H1 - receptors. Histamine is therefore not enough free binding sites to exert its effects (eg, skin redness, itching, hypotension and bronchospasm ). As a representative of the second generation of H1 - antihistamines, loratadine is largely free from side effects on the central nervous system, such as sedation. Loratadine also acts as FIASMA ( functional inhibitors of acid sphingomyelinase ). The plasma half -life is around eight hours. Metabolites in case of 12 to 24 hours

Side effects

In addition to non-specific side effects such as headache, fatigue and disorders of the gastrointestinal tract are uncommon dryness of the mouth and in some cases, hair loss, liver dysfunction, and allergic reactions. Chance also Cardiac arrhythmias are observed. In rare cases it can also cause tinnitus.

Interactions

Loratadine is metabolized by the enzyme CYP3A4. Concomitant use of agents that inhibit the enzyme CYP3A4 or have similar side effects, such as ketoconazole, erythromycin, macrolide antibiotics, HIV protease inhibitors, propafenone and grapefruit juice side effects listed above can be strengthened, particularly cardiac arrhythmias.

Patent dispute

After the expiry of the patent period for the production of loratadine, a larger legal dispute arose: Schering- Plough sued Geneva Pharmaceuticals for the production of loratadine generic based on the argument that Schering -Plough an even more valid patent on the artificial production of loratadine metabolites descarboethoxyloratadine ( desloratadine ) have. Since the loratadine in humans also leads to the formation of descarboethoxyloratadine infringes the production of loratadine this patent. The U.S. federal appeals court ruled in favor of Geneva, which led to strong concerns among pharmaceutical companies on the protection of its products.

Trade names

Allernon (A), Claritin (CH), Clarityn (A), Lisino (D ) and various generics (D, A, CH)

  • With pseudoephedrine: Clarinase (A)
CAS registry number PubChem Anatomical Therapeutic Chemical Classification System DrugBank Receptor antagonist Histamine receptor Active ingredient Allergy Xerostomia Schering-Plough Digital Object Identifier
528862
de