How long does Cetirizine take to work?

Claritin is the brand name for loratadine tablets. Generally, the onset of action after oral administration of loratadine occurs within 1–3 hours, although this may vary slightly depending on individual metabolism and the severity of allergic symptoms. If in doubt, it is recommended to consult a healthcare professional in advance. Detailed analysis is as follows:

For individuals with mild allergy symptoms and normal metabolic function, symptom relief can typically be felt within 1–2 hours after taking the medication. After absorption through the gastrointestinal tract, the drug quickly exerts its antihistamine effect, alleviating discomfort such as sneezing and skin itching. In these cases, the response is fast and stable, effectively improving everyday mild allergic symptoms.

However, for individuals with more severe allergic reactions, or those with impaired liver or kidney function and slower metabolism, the onset of action may be delayed to 2–3 hours or even longer. During severe allergic reactions, large amounts of histamine are released in the body, requiring the drug to accumulate to a certain concentration before becoming effective. Additionally, metabolic abnormalities can slow down drug absorption, further delaying the onset of action. In such cases, it may take 1–2 days of continuous use to achieve optimal results.

Before taking loratadine tablets, ensure there is no history of drug allergy and follow the recommended dosage to avoid overdose. If symptoms do not improve or worsen after taking the medication, seek medical attention promptly to adjust the treatment plan. During treatment, avoid driving or operating precision instruments, and stay away from allergens to enhance therapeutic effectiveness.