Formoterol fumarate is a long-acting β2-adrenergic receptor agonist (β2-agonist). Inhaled formoterol fumarate acts locally in the lung as a bronchodilator. In vitro studies have shown that formoterol has more than 200-fold greater agonist activity at β2-receptors than at β1-receptors. Although β2-receptors are the predominant adrenergic receptors in bronchial smooth muscle and β1-receptors are the predominant receptors in the heart, there are also β2-receptors in the human heart comprising 10%-50% of the total beta-adrenergic receptors. The precise function of these receptors has not been established, but they raise the possibility that even highly selective β2-agonists may have cardiac effects.

The pharmacologic effects of β2-adrenoceptor agonist drugs, including formoterol, 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.

In vitro tests show that formoterol is an inhibitor of the release of mast cell mediators, such as histamine and leukotrienes, from the human lung. Formoterol also inhibits histamine-induced plasma albumin extravasation in anesthetized guinea pigs and inhibits allergen-induced eosinophil influx in dogs with airway hyper-responsiveness. The relevance of these in vitro and animal findings to humans is unknown.

Treatment of Asthma: Formoterol Fumarate is indicated for the treatment of asthma and in the prevention of bronchospasm only as concomitant therapy with a long-term asthma control medication, such as an inhaled corticosteroid, in adults and children 5 years of age and older with reversible obstructive airways disease, including patients with symptoms of nocturnal asthma.

Prevention of Exercise-Induced Bronchospasm: Formoterol Fumarate is also indicated for the acute prevention of exercise-induced bronchospasm in adults and children 5 years of age and older, when administered on an occasional, as-needed basis. Use of Formoterol Fumarate as a single agent for the prevention of exercise-induced bronchospasm may be clinically indicated in patients who do not have persistent asthma. In patients with persistent asthma, use of Formoterol Fumarate for the prevention of exercise-induced bronchospasm may be clinically indicated, but the treatment of asthma should include a long-term asthma control medication, such as an inhaled corticosteroid.

Maintenance Treatment of Chronic Obstructive Pulmonary Disease: Formoterol Fumarate is indicated for the long-term, twice daily (morning and evening) administration in the maintenance treatment of bronchoconstriction in patients with Chronic Obstructive Pulmonary Disease including chronic bronchitis and emphysema.

Inhalation Acute bronchospasm; Reversible airways obstruction:

• As inhalation cap: 12 mcg twice daily, up to 24 meg twice daily in severe cases.
• As dry powder inhaler: 6 or 12 mcg 1 -2 times/day, up to to 24 mcg twice daily in sever cases. As metered doses from aerosol inhaler: 12 or 24 mcg twice daily.

Prevention of exercise-induced bronchospasm: 6 or 12 mcg at least 15 mins before exercise. Additional doses may be given 12 hr later.

Hypersensitivity.

Common side effects are Viral infection, Bronchitis, Chest infection, Dyspnea , Chest pain, Tremor, Dizziness, Angina, Arrhythmias, Hypo/hypertension, Tachycardia, Hypokalemia, Hyperglycemia, Metabolic acidosis, Headache, Insomnia, Paradoxical bronchospasm, Severe asthma exacerbation

Thyrotoxicosis; severe CV disorders e.g. ischaemic heart disease, tachyarrhythmias or severe heart burn; prolonged QT-interval. DM; pregnancy; lactation; children, do not initiate or increase the dose during an exacerbation. May produce paradoxical bronchospasm.

Pregnancy & Lactation

Pregnancy Category-C. Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks

Lactation: Not known if it is excreted in breast milk or not.