desloratadine

Desloratadine is a second-generation antihistamine used to treat allergic conditions. It is the primary active metabolite of loratadine and functions as a selective antagonist of peripheral histamine H1 receptors. Compared with first-generation antihistamines, desloratadine has a lower tendency to cause central nervous system effects and sedation.

Indications include relief of symptoms of seasonal allergic rhinitis, perennial allergic rhinitis, and chronic idiopathic urticaria (hives). It helps reduce sneezing, itching, rhinorrhea, and urticarial lesions, improving overall comfort during allergic episodes.

Pharmacology and mechanism of action: desloratadine blocks H1 receptors outside the brain, which accounts for its relatively minimal sedative effect. It has a long duration of action and is commonly taken once daily. The drug is rapidly absorbed after oral administration and is extensively metabolized in the liver, with the active metabolite contributing to its effects.

Administration and dosing: desloratadine is available in tablet and liquid forms. The typical adult dose is 5 mg once daily, with pediatric dosing adjusted by age and weight. Dose adjustments may be recommended for severe hepatic impairment or significant kidney disease; always follow a clinician’s guidance.

Safety and adverse effects: common adverse events include headache, fatigue, and dry mouth. Sedation is uncommon but can occur in some individuals. Desloratadine is contraindicated in people with hypersensitivity to the drug. Caution is advised in liver or kidney disease, and potential drug interactions should be reviewed with a healthcare professional.

Interactions: desloratadine exposure may increase with potent inhibitors of cytochrome P450 enzymes; use with such drugs requires medical supervision. Alcohol generally has minimal additive effects on alertness, but caution is advised.