Well absorbed following oral administration. Extensively metabolized by the liver, partially converted to desmethylastemizole, which has antihistaminic activity. Patients taking ketoconazole , itraconazole, erythromycin, or other macrolide anti-infectives. History of syncope during previous astemizole therapy. Underlying cardiovascular disease.
Food decreases the absorption of astemizole.
Assess lung sounds and character of bronchial secretions. May cause false-negative allergy skin testing. Administer on an empty stomach. May cause drowsiness. Caution patient to avoid driving or other activities requiring alertness until response to medication is known.