GENERIC MANE: salmeterol
DRUG CLASS AND MECHANISM: Asthma is a breathing problem involving narrowing of the airways. Airways are breathing passages that allow air to move in and out of the lungs. In patients with asthma, airways can be narrowed by accumulation of mucus, spasm of the muscles that surround these airways, or swelling of the lining of the airways. Airway narrowing lead to symptoms of shortness of breath, wheezing, cough and congestion. Medications used in treating asthma open airways are called bronchodilators. Salmeterol is a bronchodilator of the beta-2 agonist type. Beta-2 agonists are medications that stimulate beta-2 receptors on the smooth muscle cells that line the airways, causing these muscle cells to relax, thus, opening airways.

Certain allergens (such as pollen) can cause airway narrowing by inducing release of histamine by mast cells. Histamine is a natural chemical that causes tissue swelling and other allergic reactions in the body when released into the tissue. Mast cells belong to a class of immune cells located around the airways. Salmeterol is an inhaled medication that blocks the release of histamine by the mast cells, thus preventing airway narrowing when exposed to allergens.

PRESCRIPTION: yes

GENERIC AVAILABLE: no

PREPARATIONS: Canisters (13g with 120 inhalations and 6.5g with 60 inhalations).

STORAGE: Salmeterol should be stored between 36 and 86 degrees F. The canister should be kept away from heat or flame and not punctured; it should not be frozen or placed in direct sunlight .

PRESCRIBED FOR: Salmeterol is used twice daily (morning and evening) for the maintenance treatment of asthma and in preventing spasm of the airways (bronchospasm) in patients 12 years and older. Salmeterol is also used for the prevention of exercise induced asthma. Salmeterol is a long-acting beta-2 agonist, its action starts within 15 minutes and can last more than 12 hours. Therefore, salmeterol is useful in patients that require frequent administration of short acting beta-2 agonists, such as albuterol, for control of their asthma symptoms. Salmeterol is generally not used in patients whose asthma symptoms can be easily controlled with infrequent administration of short acting inhalers. Some patients with chronic bronchitis and emphysema may also benefit from salmeterol when their symptoms are related to reversible airway narrowing.

DOSING: Salmeterol inhalations should not be used more often than prescribed (twice per day) and proper techniques of inhalation closely followed. Salmeterol is metabolized by the liver and should be used with caution in patients with liver dysfunction. Salmeterol is not meant to be used in treating acute asthma attacks; short acting inhaler medications are used for acute attacks. When using salmeterol in preventing exercised induced asthma, the medication is administered 30 to 60 minutes before exercise. Salmeterol does not take the place of oral or inhaled corticosteroids.

DRUG INTERACTIONS: Salmeterol can increase heart rate, blood pressure, and cause chest pain and excitement, especially if used in higher doses than recommended or used in those with coronary heart disease or high blood pressure. Tricyclic antidepressants and salmeterol should not be combined because of additive effect on the vascular system. In rare instances, salmeterol can induce paradoxical worsening of bronchospasm (which can be life-threatening). If this occurs, salmeterol should be discontinued, and the doctor notified immediately. Rare allergic reactions to salmeterol can cause skin rash, hives, swelling, bronchospasm, and anaphylaxis. Worsening of diabetes and lowering of potassium have also been described.

PREGNANCY: Adequate studies of salmeterol during pregnancy have not been done. In some, but not all, pregnant animal models exposure to very high doses of oral salmeterol has led to offspring with birth defects. The concentrations of salmeterol in the blood after these very high doses, however, were much higher than the concentrations observed after inhalation. Salmeterol inhalation should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

NURSING MOTHERS: In rats, salmeterol is excreted in milk. Therefore, caution should be exercised when salmeterol is administered to nursing women.

SIDE EFFECTS: Side effects include palpitations, fast heart rate, elevated blood pressure, tremor, nervousness, and headache. Throat and upper airway irritation can occur.