| Verifiedrevid: | 460777963 |
| Width: | 222 |
| Tradename: | Clarinex, Aerius, Allex, others[1] |
| Dailymedid: | Desloratadine |
| Pregnancy Au: | B1 |
| Routes Of Administration: | By mouth |
| Atc Prefix: | R06 |
| Atc Suffix: | AX27 |
| Legal Au: | S2 |
| Legal Ca: | OTC |
| Legal Uk: | POM |
| Legal Us: | Rx-only |
| Legal Us Comment: | [2] [3] |
| Legal Eu: | Rx-only |
| Legal Eu Comment: | [4] |
| Bioavailability: | Rapidly absorbed |
| Protein Bound: | 83 to 87% |
| Metabolism: | UGT2B10, CYP2C8 |
| Metabolites: | 3-Hydroxydesloratadine |
| Onset: | within 1 hour |
| Elimination Half-Life: | 27 hours, 33.7 hours in elderly patients |
| Duration Of Action: | up to 24 hours |
| Excretion: | 40% as conjugated metabolites into urine Similar amount into the feces |
| Cas Number: | 100643-71-8 |
| Pubchem: | 124087 |
| Iuphar Ligand: | 7157 |
| Drugbank: | DB00967 |
| Chemspiderid: | 110575 |
| Unii: | FVF865388R |
| Kegg: | D03693 |
| Chebi: | 291342 |
| Chembl: | 1172 |
| Synonyms: | descarboethoxyloratadine[5] |
| Iupac Name: | 8-chloro-6,11-dihydro-11-(4-piperdinylidene)- 5H-benzo[5,6]cyclohepta[1,2-b]pyridine |
| C: | 19 |
| H: | 19 |
| Cl: | 1 |
| N: | 2 |
| Smiles: | Clc4cc2c(C(/c1ncccc1CC2)=C3/CCNCC3)cc4 |
| Stdinchi: | 1S/C19H19ClN2/c20-16-5-6-17-15(12-16)4-3-14-2-1-9-22-19(14)18(17)13-7-10-21-11-8-13/h1-2,5-6,9,12,21H,3-4,7-8,10-11H2 |
| Stdinchikey: | JAUOIFJMECXRGI-UHFFFAOYSA-N |
Desloratadine. sold under the brand name Clarinex among others, is a tricyclic H1 inverse agonist that is used to treat allergies. It is an active metabolite of loratadine.[6]
It was patented in 1984 and came into medical use in 2001.[7] It was brought to the market in the US by Schering Corporation, later named Schering-Plough.
Desloratadine is used to treat allergic rhinitis, nasal congestion and chronic idiopathic urticaria (hives).[8] It is the major metabolite of loratadine and the two drugs are similar in safety and effectiveness.[8] Desloratadine is available in many dosage forms and under many brand names worldwide.[9]
An emerging indication for desloratadine is in the treatment of acne, as an inexpensive adjuvant to isotretinoin and possibly as maintenance therapy or monotherapy.[10] [11]
The most common side-effects are fatigue (1.2%), dry mouth (3%[12]), and headache (0.6%[12]).[8]
Co-administration with erythromycin, ketoconazole, azithromycin, fluoxetine, or cimetidine resulted in elevated blood plasma concentrations of desloratadine and its metabolite 3-hydroxydesloratadine in studies. However, no clinically relevant changes were observed.[13]
Desloratadine is a selective H1-antihistamine which functions as an inverse agonist at the histamine H1 receptor.[14]
At very high doses, is also an antagonist at various subtypes of the muscarinic acetylcholine receptors. This effect is not relevant for the drug's action at therapeutic doses.[15]
Desloratadine is well absorbed from the gut and reaches highest blood plasma concentrations after about three hours. In the bloodstream, 83 to 87% of the substance are bound to plasma proteins.
Desloratadine is metabolized to 3-hydroxydesloratadine in a three-step sequence in normal metabolizers. First, N-glucuronidation of desloratadine by UGT2B10; then, 3-hydroxylation of desloratadine N-glucuronide by CYP2C8; and finally, a non-enzymatic deconjugation of 3-hydroxydesloratadine N-glucuronide.[16] [17] Both desloratadine and 3-hydroxydesloratadine are eliminated via urine and feces with a half-life of 27 hours in normal metabolizers.[18]
It exhibits only peripheral activity since it does not readily cross the blood–brain barrier; hence, it does not normally cause drowsiness because it does not readily enter the central nervous system.[19]
Desloratadine does not have a strong effect on a number of tested enzymes in the cytochrome P450 system. It was found to weakly inhibit CYP2B6, CYP2D6, and CYP3A4/CYP3A5, and not to inhibit CYP1A2, CYP2C8, CYP2C9, or CYP2C19. Desloratadine was found to be a potent and relatively selective inhibitor of UGT2B10, a weak to moderate inhibitor of UGT2B17, UGT1A10, and UGT2B4, and not to inhibit UGT1A1, UGT1A3, UGT1A4, UGT1A6, UGT1A9, UGT2B7, UGT2B15, UGT1A7, and UGT1A8.
2% of Caucasian people and 18% of people from African descent are desloratadine poor metabolizers. In these people, the drug reaches threefold higher plasma concentrations at seven hours after intake, and it has a half-life of 89 hours (compared to a 27-hour half-life in normal metabolizers). Adverse effects were reported at similar rates in poor metabolizers, suggesting that it is not clinically relevant.