answer
Saba is the first choice for acute attack of asthma, but not SAMA.
(Note: the following drugs refer to inhaled preparations)
analysis
β There are many kinds of 2-receptor agonists, which can be divided into short-term (maintenance time 4-6 h), long-term (maintenance time 10-12 h, suitable for bid) and super long-term (maintenance time 24 h, suitable for QD).
Long term effect β 2 receptor agonists (Laba) can also be divided into fast acting Laba (such as formoterol, indarterol, vilanterol and odaterol) and slow acting Laba (such as salmeterol).
Short acting anticholinergic drug (SAMA) is the most commonly used ipratropium bromide, lasting for 6-8 hours, while long acting anticholinergic drug (Lama) is more commonly used tiotropium bromide, lasting for 24 hours, so it is QD.
Short acting β 2 receptor agonist (Saba) can rapidly relieve bronchospasm, usually within a few minutes, and the curative effect can last for several hours. It is the first choice and the most effective drug to relieve the acute symptoms of asthma [1].
Saba salbutamol, the most commonly used, takes effect 3-5 minutes after inhalation and lasts for 4-6 hours; However, the pulmonary function was significantly improved 15 min after inhalation of ipratropium bromide (SAMA), and reached the peak 1-2 h later, with a maintenance time of 6-8 hours, so the onset of SAMA was slow.
So how slow does SAMA work? Finally, I found the answer
Basic guidelines for routine pulmonary function examination in 2018 [2]:
If Saba such as salbutamol was inhaled, the ventilation function test should be repeated 15-30 minutes after inhalation;
If the patients were treated with salbutamol (SAMA), the examination should be repeated 30-60 min after inhalation.
It also shows that the effect of SAMA is slow and weak.
How to use Saba and SAMA?
The overall treatment goal of acute asthma attack is to relieve symptoms, relieve bronchospasm, improve hypoxia, restore lung function, prevent further deterioration or recurrence, and prevent complications.
The bronchodilation effect of SAMA is relatively weak. In acute attack, it is not suitable to use it alone, but should be combined with Saba, and the bronchodilation effect is better. The management process of acute asthma attack can be seen in Figure 1.
Specific usage of Saba and SAMA:
Mild to moderate acute attack: 4-10 sprays in the first hour and 20 minutes can effectively reverse airflow limitation (A-level evidence) [3], then according to the treatment response, mild acute attack is adjusted to 2-4 sprays in the third to fourth hour, and moderate acute attack is adjusted to 6-10 sprays in the first to second hour. The response to the initial inhalation of Saba was good, dyspnea was significantly relieved, PEF accounted for more than 60% – 80% of the expected value, and the curative effect was maintained for 3-4 hours, so other drugs were usually not needed. Saba and SAMA aerosol solution can also be inhaled once every 4-6 hours.
Moderate to severe acute attack: self-treatment should be carried out according to the above plan, and the patients should go to the hospital as soon as possible. After arriving at the hospital, Saba is the first choice. In the initial stage, intermittent (every 20 minutes) or continuous atomization administration is recommended, followed by intermittent administration as needed (once every 4 hours). Saba combined with SAMA aerosol solution inhalation can be used for patients with moderate to severe asthma acute attack or poor effect after Saba treatment [1].
summary
The overall treatment goal of acute asthma attack is to relieve symptoms, relieve bronchospasm, improve hypoxia, restore lung function, prevent further deterioration or recurrence, and prevent complications;
Saba is the first choice for acute attack of asthma;
The bronchodilation effect of SAMA is weak and the onset is slow. Patients with poor effect after Saba treatment can be treated with Saba combined with SAMA aerosol solution inhalation.