|Systematic (IUPAC) name|
|Licence data||EMA: , US FDA:|
|Pregnancy cat.||B1 (AU) C (US)|
|Legal status||POM (UK) ℞-only (US)|
|Excretion||40% as conjugated metabolites into urine
Similar amount into the feces
|(what is this?)|
Desloratadine is a drug used to treat allergies. It is marketed under several trade names such as NeoClarityn, Claramax, Clarinex, Larinex, Aerius, Dazit, Azomyr, Deselex and Delot. It is an active metabolite of loratadine, which is also on the market.
Desloratadine is available as tablets (including orally disintegrating and extended release) and as syrup. In Colombia (South America) it is marketed under Dexio from Laboratorios Bussié, as tablets and as syrup to children. In Nepal and India it is widely available under the trade name Daziti and Dazit.
Mechanism of action
Desloratadine is a tricyclic antihistamine, which has a selective and peripheral H1-antagonist action. It is an antagonist at histamine H1 receptors, and an antagonist at all subtypes of the muscarinic acetylcholine receptor. It has a long-lasting effect and in moderate and low doses, does not cause drowsiness because it does not readily enter the central nervous system. Unlike other antihistamines, desloratadine is also effective in relieving nasal congestion, particularly in patients with allergic rhinitis. 
Most common side-effects are fatigue, dry mouth, headache, and gastrointestinal disturbances.
Desloratadine vs. loratadine
Desloratadine is the major metabolite of loratadine. There are no head-to-head randomised controlled trials of the two drugs. A survey of patients dissatisfied with loratadine published in August 2003 reported equal or better satisfaction with desloratadine, concluding:
When severity of disease was controlled for in the analysis, a pattern emerged suggesting greater levels of satisfaction amongst loratadine dissatisfied patients who converted to desloratadine. Point estimates suggest a consistent pattern favoring desloratadine patient satisfaction, with statistically significant results reported for sum of adverse effects, nighttime awakening due to symptoms, symptom severity just prior to the next dose, and overall satisfaction (p < 0.05).
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.
In Canada and Denmark, desloratadine is available as a generic, without a prescription, and prices are comparable to those of loratadine. In Russia and Belarus, desloratadine is also available without a prescription (Aerius by Schering-Plough; Desloratadine-Teva by Teva). However prices in these markets are much higher if compared to those of loratadine.
- FDA Electronic Orange Book http://www.fda.gov/cder/ob/default.htm.
- Mann R, Pearce G, Dunn N, Shakir S (2000). "Sedation with "non-sedating" antihistamines: four prescription-event monitoring studies in general practice". BMJ 320 (7243): 1184–6. doi:10.1136/bmj.320.7243.1184. PMC 27362. PMID 10784544.
- Horak F, Stübner UP, Zieglmayer R, Harris AG (June 2002). "Effect of desloratadine versus placebo on nasal airflow and subjective measures of nasal obstruction in subjects with grass pollen-induced allergic rhinitis in an allergen-exposure unit". J. Allergy Clin. Immunol. 109 (6): 956–61. PMID 12063524.
- Glass D, Harper A (August 13, 2003). "Assessing satisfaction with desloratadine and fexofenadine in allergy patients who report dissatisfaction with loratadine". BMC Fam Pract 4: 10. doi:10.1186/1471-2296-4-10. PMC 194638. PMID 12917016.
- See S (2003). "Desloratadine for allergic rhinitis". Am Fam Physician 68 (10): 2015–6. PMID 14655812.