| Asthma curative |
Salmeterol is an asthma remedy. It is developed from the molecular structure of salbutamol with only an additional tail part. This part is closely associated with the specific structure of the beta 2 receptor, the external receptor site. This allows the other parts of the molecule to act freely on the beta 2 receptor. And for this reason, this product can continue to stay in the position of action. Salmeterol can be used as a bronchodilator for long-acting beta 2 receptor agonists in daily control of asthma symptoms. It can be used for long-term treatment of asthma (including nocturnal asthma and exercise-induced asthma), reversible airway obstruction in chronic bronchitis and emphysema, and is not suitable for acute attack of asthma. |
| Antiasthmatic medicine |
Antiasthmatic drugs are the drugs that can act on the different links of the asthma attack in order to relieve or prevent the attack of asthma.
Salmeterol is a new long-acting beta 2 agonist antiasthmatic drug, derived from salbutamol, and closely linked to beta 2 receptor, resulting in more durable activation. Its chemical name is hydroxy naphthalate, which is white or white like powder with bitter taste. It was first developed by the British GlaxoSmithKline Co and was first listed in the UK in 1990.
Its commodity name is Serevent, Salmeterol Xinafoate Aerosol,Sertindole and Salmeterol. It can inhibit the release of hypersensitivity mediators from the mast cells in the lung. It can inhibit the early and late phase reaction induced by inhalation antigen and reduce the hyperresponsiveness of the trachea. Clinical trials show that is salmeterol stronger than salbutamol. It has a longer duration effect to protect asthma caused by histamine induced bronchoconstriction and movement. It features long duration, small extrapulmonary effect and good tolerance. It is an ideal drug for the treatment of nocturnal attack and asthma. The pharmacokinetic study has indicated that this dose of this product twice a day, 50μg each time. 5～15 min after 1 inhalation of 50 and 400μg, the highest plasma concentration will be 0.1 to 0.2μg /L and 1 ~ μg/L respectively. This product is strongly metabolizing by hydrolysis, and most of the dosage is eliminated in 72h. The doses of 23% and 57% in 168h can be found in urine and feces respectively. In addition, salmeterol has a controlled effect on histamine, leukotrienes and prostaglandins. It is worth notice that this product can not be used with non selective beta blockers for the treatment of asthma, and it should be prudent for patients with asthma with heart disease. Salmeterol 's common adverse reactions include hypokalemia, abnormal bronchospasm, tremor, headache, and palpitations. Its common beta agonists include: ephedrine, isoproterenol, salbutamol, terbutaline, clenbuterol, clorprenaline, tulobuterol, clenbuterol, procaterol, salmeterol, bambuterol, methoxyphenamine, rimiterol, bitolterol, sonarin, butero, fenoterol etc.. |
| Clinical evaluation |
It has been proved that this product dose is 50μg, inhaled 2 twice a day, and is effective for mild to moderate asthma. In patients with moderate asthma, it will be more efficient to take a dose of 100μg by inhalation twice a day. The effect is longer and up to 12 h.
It has been proved that the dose of 5050μg by inhaling twice a day will be more effectivethan the dose of 200μg salbutamol by inhaling 4 times a day in improving lung function and lightening the day and night respiratory syndrome. Salmeterol aerosol should used in adult bronchial asthma, 50μg each time, twice a day (morning, before bedtime), and the longest medication time is 71 weeks. The results shows an obvious tendency to improve compared with the pre medication. The improvement in the fourth week after administration is 15%. The moderate improvement is 50%, and the mild improvement is 72.5%. The improvement rate of long-term medication is 15%, 68.2% and 88.6%, respectively. 18 patients with bronchial asthma have been given aerosol 25μg and inhalation powder 25μg each time. The results have indicated that FEV10, PEFR, MMEF, V50 and V25 begin to be improved after 25 min, and their effects have maintained for 8h. The results of lung function examination after inhalation of 4h are the same.
Both the total improvement and the moderate improvement are both 81.8%, and the effectis completely equal. For the patients with asthma at night, inhalation of 50μg and 100μg every day for twice can obviously improve the expiratory flow rate throughout the night and increase the percentage of sleep in patients with nocturnal asthma.
These indexes are superior to placebo. Most studies have shown that this product improves the quality of sleep in the subjects. |
| Uses |
Bronchodilator. |
| Definition |
ChEBI: A phenol having a hydroxymethyl group at C-2 and a 1-hydroxy-2-{[6-(4-phenylbutoxy)hexyl]amino}ethyl group at C-4; derivative of phenylethanolamine. |
| Hazard |
A poison by inhalation. |
| Biological Activity |
Potent and selective β 2 -adrenoceptor agonist (EC 50 = 5.3 nM); bronchodilator. Unlike other β 2 agonists, binds to exo-site domain of β 2 receptors, producing a slow onset of action and prolonged activation. Also available as part of the β -Adrenoceptor Agonist Tocriset™ . |
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