Pharmacology: Pharmacodynamics: Loratadine is a non-sedative histamine H1 receptor antagonist with anti-allergic properties. It binds selectively to peripheral histamine H1 receptors with a lower affinity to brain H1 receptors. It is a long-acting antihistamine with little anti-muscarinic activity.
Pharmacokinetics: Loratadine is rapidly and almost completely absorbed after oral administration. Loratadine is about 98% bound to plasma proteins. It crosses the placental barrier and is detected in the human breast milk. Loratadine is extensively and rapidly metabolized in the liver to form a major metabolite, descarboethoxyloratadine. Descarboethoxyloratadine has potent histamine H1 blocking activity. Loratadine and its metabolites are excreted in the urine and faeces.