Desloratadine
Desloratadine is a long-acting tricyclic histamine antagonist with selective H1-receptor activity. Its label indicates it for the relief of nasal and non-nasal symptoms of allergic rhinitis, and it is one of the antihistamines chosen when the sedation of an older agent is unwanted.
Key points
- The label indicates it for the relief of the nasal and non-nasal symptoms of seasonal allergic rhinitis in patients 2 years of age and older.
- For perennial allergic rhinitis, meaning symptoms that persist year round rather than in a season, it is indicated in patients 6 months of age and older.
- Neither food nor grapefruit juice had an effect on the bioavailability of desloratadine, measured as Cmax and AUC.
- Co-administration with cimetidine raised plasma concentrations of desloratadine and its metabolite, but produced no clinically relevant changes in the safety profile.
How it works
The label describes desloratadine as a long-acting tricyclic histamine antagonist with selective H1-receptor histamine antagonist activity. Selectivity for the H1 receptor, without the central effects of an older sedating antihistamine, is what allows it to be taken during the day.
The two age limits in the indication are worth reading carefully, because they differ by condition rather than by product: seasonal allergic rhinitis from 2 years, perennial allergic rhinitis from 6 months.
Safety specific to desloratadine
Food and grapefruit. The label records that neither food nor grapefruit juice had an effect on the bioavailability of desloratadine, measured as Cmax and AUC. That is a useful practical fact rather than a warning, and it distinguishes this medicine from several others where grapefruit matters.
Cimetidine. In controlled clinical studies, co-administration of desloratadine with cimetidine, a histamine H2-receptor antagonist, resulted in increased plasma concentrations of desloratadine and 3-hydroxydesloratadine, but there were no clinically relevant changes in the safety profile of desloratadine. The hedge is the label’s own: concentrations rose, and the observed safety profile did not change.
Further reading
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