Which of the following drug causes least sedation?
Loratadine is a second-generation tricyclic H1 histamine antagonist which acts as a selective inverse agonist of peripheral histamine H1-receptors. As a "non-sedating" antihistamine, loratadine causes less sedation and psychomotor retardation than the older antihistamines because it penetrates the blood brain barrier to a smaller extent. Other possible side-effects include headache and antimuscarinic effects such as urinary retention, dry mouth, blurred vision, and gastrointestinal disturbances.
Hydroxazine
Phenergan
Chlopheneramine
Loratidine