Information about Loratadine
Loratadine and its metabolic derivative desloratadine are second generation antihistamines that are used for the treatment of allergic rhinitis, angioedema and chronic urticaria.
Liver safety of Loratadine
Loratadine and desloratadine have been linked to rare, isolated instances of clinically apparent acute liver injury.
Mechanism of action of Loratadine
Loratadine (lor at' a deen) and desloratadine (des" lor at' a deen) are second generation antihistamines (H1 receptor blockers) that are used widely to treat allergic symptoms associated with hay fever, seasonal allergies, urticaria, angioedema and atopic dermatitis. Like other second generation antihistamines, loratadine and desloratadine are considered to be nonsedating, and prospective studies have shown that sedation is less common with them than first generation antihistamines such as diphenhydramine. Loratadine and desloratadine belong to the piperidine class of antihistamines (similar to fexofenadine). The two agents appear to have a similar spectrum of activity and side effects, although some patients are found to prefer one over the other.
FDA approval information for Loratadine
Loratadine was approved for use by prescription in the United States in 1993 and as an over-the-counter medication in 2002.
Brand name for Loratadine
It is available in 5 and 10 mg tablets and capsules generically and under the trade name Claritin.
Dosage and administration for Loratadine
The typical dose is 10 mg once daily and it is often given chronically, at least during allergic season.
Desloratadine, which is the major metabolite of loratadine, was approved for use in the United States in 2001 and is currently available by prescription only in tablets of 2.5 or 5 mg in multiple generic forms and under the trade name Clarinex.
Side effects of Loratadine
Common side effects of second generation antihistamines include blurred vision, dry mouth and throat, palpitations, tachycardia, abdominal distress, constipation and headache. Although considered to be nonsedating antihistamines, loratadine and desloratadine can cause mild drowsiness particularly at higher doses. Antihistamines can worsen urinary retention and glaucoma.
First Generation Antihistamines
Second Generation Antihistamines