There are no clear rules about how many days you need to take loratadine for allergic asthma. However, clinically it is generally recommended to take about 1 week, the specific use of drugs need to strictly follow the doctor’s instructions. Loratadine belongs to the antihistamine, commonly used dosage forms include tablets, capsules, granules, dispersible tablets and chewable tablets. Clinically, it is mainly used to relieve allergic rhinitis caused by nasal itching and running, sneezing, nasal congestion, eye itching and burning sensation and other symptoms. It can also be taken for chronic urticaria, allergic asthma, itchy skin diseases and other allergic diseases. It is forbidden to take it if you are allergic to the composition of the drug loratadine. Loratadine is used with caution in people with renal insufficiency, a history of cardiac arrhythmias and allergies. Breastfeeding must be stopped while taking the drug. Adverse reactions such as headache, drowsiness, fatigue, dry mouth, nausea, gastritis and rash may occur after current use of the drug. Allergic asthmatics need to take loratadine under the guidance of a professional doctor, usually can be taken for 1 week, such as after the use of the drug does not see relief, need to consult the hospital in a timely manner, so as to avoid delaying the condition.