Oral. Take the medicine daily 1 time. Because asthma often attacks or worsens in the early hours of the morning, it is best to take the medicine at 8 ~ 9 pm. (1) Adult patients: Generally, 1 time per day (200mg), patients with serious illness or chronic diseases should take 1 time (200mg, at 8-9am), but the dosage should be gradually increased from small dosage according to individual differences, and the maximum dosage per day should not exceed 600mg. When the dose is large, it can be taken twice a day in the morning and evening, and the blood concentration should be determined as much as possible to adjust the dose. (2) Children over 3 years old can start treatment with 100mg, and the maximum daily dose should not exceed 10mg/kg.