Desloratadine

Desloratadine is a drug used to treat allergies. It is marketed under several trade names such as NeoClarityn®, Claramax®, Clarinex® and Aerius®. It is an active metabolite of loratadine, which is also on the market.

Descarboethoxyloratadine
8-chloro-6,11-dihydro-11-(4-piperdinylidene)- 5H-benzo[5,6]cyclohepta[1,2-b]pyridine
Molecular Weight	310.82
Empiric Formula	C19H19ClN2
ATC code	R06AX27
Metabolism	Liver
Pregnancy category	C (USA) B1 (Aus)

Available forms

Desloratadine is available as tablets and oral suspension.

Mechanism of action

Desloratadine is a tricyclic antihistamine, which has a selective and peripheral H₁-antagonist action. It has a long-lasting effect and does not cause drowsiness because it does not readily enter the central nervous system. It is 10-20 times more potent as an antihistamine than loratadine.

Pharmacokinetics

Desloratadine is rapidly absorbed from the gastro-intestinal tract. Desloratadine is moderately bound to plasma proteins (85%). The half-life of desloratadine is on average 28 hours. About 40% is excreted as conjugated metabolites into the urine and similar amount into the feces. Traces of unmetabolised desloratadine can be found in the urine.

Side effects

Most common side-effects are fatigue, drowsiness, dry mouth, headache, and gastrointestinal disturbances.

Desloratadine vs. loratadine

A November 2003 article published in the journal American Family Physician about the safety, tolerability, effectiveness, price, and simplicity of desloratadine concluded the following:

Desloratadine is similar in effectiveness to fexofenadine and would be expected to produce results similar to loratadine and other nonsedating antihistamines. There is no clinical advantage to switching a patient from loratadine to desloratadine. However, it may be an option for patients whose medical insurance no longer covers loratadine if the co-pay is less than the cost of the over-the-counter product.

External link

• Desloratadine for Allergic Rhinitis, a November 2003 article from American Family Physician