Salmeterol

Mechanism :

Salmeterol is a selective, long-acting beta2-adrenergic agonist. The pharmacologic effects of beta2-adrenoceptor agonist drugs, including salmeterol, are at least in part attributable to stimulation of intracellular adenyl cyclase, the enzyme that catalyzes the conversion of adenosine triphosphate (ATP) to cyclic-3,5 -adenosine monophosphate (cyclic AMP). Increased cyclic AMP levels cause relaxation of bronchial smooth muscle and inhibition of release of mediators of immediate hypersensitivity from cells, especially from mast cells.

Indication :

Persistent Asthma

Contraindications :

Hypersensitivity to any ingredient of the preparation. Should not be started in patients with significantly worsening or acutely deteriorating asthma. Not designed to relieve acute asthma symptoms.

Dosing :

<4 years:

Safety and efficacy not established.

>4 years:

50 mcg (1 oral inhalation) 2 times daily. It should not be used without an asthma controller medication (i.e. inhaled corticosteroid).

Adverse Effect :

Commonly seen adverse effects are pain, nasal congestion, migraine, dizziness, sleep disturbances, tremor, subjective palpitations, headache, tachycardia, hyperglycemia, hypokalemia and paradoxical bronchospasm with aerosol inhaler. Skin reactions, muscle cramps, non-specific chest pain, local irritation and arthralgia have been reported.

Interaction :

Monoamine Oxidase Inhibitors and Tricyclic Antidepressants: Salmeterol should be administered with extreme caution to patients being treated with monoamine oxidase inhibitors or tricyclic antidepressants, or within 2 weeks of discontinuation of such agents, because the action of salmeterol on the vascular system may be potentiated by these agents.
Corticosteroids and Cromoglycate: Inhaled corticosteroids and/or inhaled cromolyn sodium did not alter the safety profile of salmeterol when administered concurrently.
Beta-Adrenergic Receptor Blocking Agents: Beta-blockers not only block the pulmonary effect of beta-agonists, but may also produce severe bronchospasm in patients with asthma or COPD.
Diuretics: The ECG changes and/or hypokalemia that may result from the administration of non-potassium-sparing diuretics (such as loop or thiazide diuretics) can be acutely worsened by beta-agonists.

Hepatic Dose :

Dose reduction may be required as drug has extensive hepatic metabolism and hepatic impairment can cause increased drug accumulation.