Aerinaze contains two active substances: desloratadine, an antihistamine, and pseudoephedrine, which is a nasal decongestant. Desloratadine works by blocking the receptors on which histamine, a substance in the body that causes allergic symptoms, normally fixes itself. When the receptors are blocked, histamine cannot have its effect, and this leads to a decrease in the symptoms of allergy. Pseudoephedrine works by stimulating nerve endings to release the chemical noradrenaline, which causes the blood vessels to constrict (narrow). This reduces the amount of fluid released from the vessels, resulting in less swelling and less mucus production in the nose. In Aerinaze, the two active substances are used together, since an antihistamine alone may not provide adequate relief for patients with nasal congestion.
Aerinaze tablets have two layers, one containing desloratadine, and the other containing pseudoephedrine. Desloratadine is released from its layer immediately after it is taken, while pseudoephedrine is released slowly over 12 hours. This means that patients only need to take the tablet twice a day.
Desloratadine has been available in the European Union (EU) since 2001, and pseudoephedrine is widely used in medicines that have been available over-the-counter for many years.