Keratan is an anti-allergic drug and patients are advised to take it before going to bed. Because anti-allergic drugs will have more or less adverse reactions, such as weakness, headache, drowsiness, after the drug may affect the normal work and life of patients, especially patients working at height or drivers, and even life-threatening, it is recommended to take it before going to bed to help ease sleep and not affect the normal work and life during the day. According to the patient’s condition regular medication for a week to observe, if necessary, and then to the hospital for further consultation, keratan medication after must drink more water to promote the absorption and metabolism of drugs. If patients have hair loss, liver function abnormalities, or even convulsions, tachycardia, must be timely to discontinue the drug and consider further consultation in the hospital.