Post Approval Pharmacokinetic Study of Loratadine in Japanese Pediatric and Adult Patients (Study P05539)

Inclusion Criteria: Patients with perennial allergic rhinitis who satisfy all of the following criteria were enrolled in the study: * Pediatric patients between the ages of 3 and 15 years and adult patients between the ages of 16 and 64 at the time of providing informed consent. * Outpatients of either sex. * Pediatric patients for whom written informed consent can be obtained from the guardian before the start of the study. Adult patients from whom written informed consent can be obtained (for patients between the ages of 16 and 19, the guardian must also provide written informed consent). * Pediatric patients who have the ability to make entries in the patient diary (Record of Drugs and Nasal Symptoms) or entry in the diary is made possible by the guardian. Adult patients who have the ability to make entries in the patient diary. * Patients for whom treatment with loratadine monotherapy is judged appropriate based on symptoms of allergic rhinitis during the pretreatment observation period. * Patients confirmed to be allergic to perennial allergen Exclusion Criteria: * Patients with a history of epileptic seizures or organic brain disorder in whom there is a possibility that epileptic seizures may be induced * Patients with a history of hypersensitivity to any component of this drug * Patients who are pregnant or who may be pregnant, and nursing women * Patients with severe hepatic, renal, cardiac, or hematological disease or other serious complications and whose general condition is poor * Patients participating in another clinical study or who have been in a clinical study within the last 30 days. * Other patients judged inappropriate for study by the investigator or sub-investigator * Patients allergic to pollen (cedar, mugwort, common ragweed, orchard grass, etc.) and the pollen season is during the period from 7 days before registration to the end of study drug administration * Patients who developed diseases which might affect nasal symptoms (acute upper respiratory tract infection, acute pharyngo-laryngitis, or acute tonsillitis) in the 7 days before registration * Patients who received treatment for allergic rhinitis in the 7 days before registration