Description:a non-sedating antihistamineindication :relieving the symptoms of nasal allergies (allergic rhinitis) such as hay fever.relieving the symptoms of an itchy skin rash with no known cause (chronic idiopathic urticaria).mechanism of action :acrivastine works by blocking histamine h1 receptors. it doesn t prevent the actual release of histamine from mast cells, but prevents it binding to its receptors. this in turn prevents the release of other allergy chemicals and increased blood supply to the area, and provides relief from the typical symptoms of nasal allergies such as hayfever.acrivastine can also be used to relieve the symptoms of various itchy rashes and hives. blocking the actions of histamine relieves the itching and reduces the rashdosage:adults and adolescents aged 12 years and over should take one capsule up to three times a day when needed to relieve symptoms.