Action of inhalation salbutamol: it is a β2 agonist, it takes effect 30 minutes after oral intake, aerosol inhalation can take effect after 5 minutes, and it can be maintained for 3-4 hours. Clinical main use: treatment of bronchospasm in patients with wheezing bronchitis, bronchial asthma, emphysema. Precautions: 1, a few people can appear nausea, headache, dizziness, palpitations, finger tremor, etc. 2, long-term use of the drug can form drug resistance, reduced efficacy, there is a risk of aggravation of asthma. 3, β-blockers can antagonize the bronchodilator effect of the product, so it is not suitable for use in combination with Propranolol. 4, caution in cardiovascular insufficiency, hypertension and hyperthyroidism.