If that is not effective, the sufferer should take another puff in half an hour, and if that does not work they should immediately be rushed to an emergency ward. If the respiratory tract has contracted to the point where the bronchodilator cannot get through, the patient will need an immediate injection before it is too late. Repeated use of a bronchodilator, however, can lead to cardiac arrhythmia.
氣喘發作時，氣管擴張劑如果噴一次沒有效果，半小時之後再噴一次，如果仍然沒有效果，就要立刻送急診，因為氣管如果收縮到一個程度，藥噴不進去，此時如果不立即打針給藥，可能就會來不及。