Salmeterol is a long-acting beta2-adrenergic receptor agonist drug that is currently prescribed for the treatment of asthma and chronic obstructive pulmonary disease COPD.
Indication
For the treatment of asthma and chronic obstructive pulmonary disease (COPD).
Pharmacology
Salmeterol is a long acting beta2-adrenoceptor agonist (LABA), usually only prescribed for severe persistent asthma following previous treatment with a short-acting beta agonist such as salbutamol and is prescribed concurrently with a corticosteroid, such as beclometasone. The primary noticable difference of salmeterol to salbutamol is that the duration of action lasts approximately 12 hours in comparison with 4-6 hours of salbutamol. When used regularly every day as presecribed, inhaled salmeterol decreases the number and severity of asthma attacks. However, it is not for use for relieving an asthma attack that has already started. Inhaled salmeterol works like other beta 2-agonists, causing bronchodilatation by relaxing the smooth muscle in the airway so as to treat the exacerbation of asthma. Salmeterol is similar in action to formoterol, however formoterol has been demonstrated to have a faster onset of action than salmeterol as a result of a lower lipophilicity, and has also been demonstrated to be more potent - a 12 µg dose of formoterol has been demonstrated to be equivalent to a 50 µg dose of salmeterol.
Toxicity
Symptoms of overdose include angina (chest pain), dizziness, dry mouth, fatigue, flu-like symptoms, headache, heart irregularities, high or low blood pressure, high blood sugar, insomnia, muscle cramps, nausea, nervousness, rapid heartbeat, seizures, and tremor. By the oral route, no deaths occurred in rats at 1,000 mg/kg (approximately 81,000 times the maximum recommended daily inhalation dose in adults and approximately 38,000 times the maximum recommended daily inhalation dose in children on a mg/m2 basis).
Affected Organisms
Humans and other mammals
Biotransformation
Hepatic, metabolized by hydroxylation via CYP3A4
Absorption
Because of the small therapeutic dose, systemic levels of salmeterol are low or undetectable after inhalation of recommended doses.
Half Life
5.5 hours
Protein Binding
96%
References
•
Salpeter SR, Buckley NS, Ormiston TM, Salpeter EE: Meta-analysis: effect of long-acting beta-agonists on severe asthma exacerbations and asthma-related deaths. Ann Intern Med. 2006 Jun 20;144(12):904-12. Epub 2006 Jun 5.
[Pubmed]
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.
References
PubChem Literature
From Data Sources
• Salpeter SR, Buckley NS, Ormiston TM, Salpeter EE: Meta-analysis: effect of long-acting beta-agonists on severe asthma exacerbations and asthma-related deaths. Ann Intern Med. 2006 Jun 20;144(12):904-12. Epub 2006 Jun 5. Pubmed
