Metaproterenol Sulfate Inhalation Solution is indicated as a bronchodilator for bronchial asthma and for reversible bronchospasm which may occur in association with bronchitis and emphysema.Following controlled single dose studies by an intermittent positive pressure breathing apparatus (IPPB) and by hand bulb nebulizers, significant improvement (15% or greater increase in FEV1) occurred within 5 to 30 minutes and persisted for periods varying from 2 to 6 hours.In these studies, the longer duration of effect occurred in the studies in which the drug was administered by IPPB, i.e.

6 hours versus 2 to 3 hours when administered by hand bulb nebulizer.

In these studies the doses used were 0.3 mL by IPPB and 10 inhalations by hand bulb nebulizer.In controlled repetitive dosing studies by IPPB and by hand bulb nebulizer the onset of effect occurred within 5 to 30 minutes and duration ranged from 4 to 6 hours.

In these studies the doses used were 0.3 mL b.i.d.

or t.i.d.

when given by IPPB and 10 inhalations q.i.d.

(no more often than q 4h) when given by hand bulb nebulizer.

As in the single dose studies, effectiveness was measured as a sustained increase in FEV1 of 15% or greater.

In these repetitive dosing studies there was no apparent difference in duration between the two methods of delivery.During other clinical tolerance studies, metaproterenol was administered q.i.d.

(by nebulizer) for periods of 60 and 90 days.

On specified days before, during and after these open label trials, patients were referred to a laboratory where the effects of single doses of metaproterenol and isoproterenol on pulmonary function were recorded (in a double blind crossover controlled setting).

Both drugs continued to exert significant improvement in function throughout this period of treatment.

---

Asthma -- A form of bronchial disorder with three distinct components: airway hyper-responsiveness (RESPIRATORY HYPERSENSITIVITY), airway INFLAMMATION, and intermittent AIRWAY OBSTRUCTION. It is characterized by spasmodic contraction of airway smooth muscle, WHEEZING, and dyspnea (DYSPNEA, PAROXYSMAL).

Bronchial spasm -- Spasmodic contraction of the smooth muscle of the bronchi.

Acute bronchitis -- sudden inflammation of the tracheobronchial tree, which comprises the trachea, or windpipe, and the bronchi; typically associated with a viral upper respiratory tract infection, such as the common cold, and is usually mild; in patients with chronic lung or heart disease, acute bronchitis is more severe, and can become chronic and progress to pneumonia.

Bronchitis -- Inflammation of the large airways in the lung including any part of the BRONCHI, from the PRIMARY BRONCHI to the TERTIARY BRONCHI.

Pathological accumulation of air in tissues -- A pathological accumulation of air in tissues or organs.

Pulmonary Emphysema -- Enlargement of air spaces distal to the TERMINAL BRONCHIOLES where gas-exchange normally takes place. This is usually due to destruction of the alveolar wall. Pulmonary emphysema can be classified by the location and distribution of the lesions.

Use in patients with cardiac arrhythmias associated with tachycardia is contraindicated.Although rare, immediate hypersensitivity reactions can occur.

Therefore, Metaproterenol Sulfate Inhalation Solution is contraindicated in patients with a history of hypersensitivity to any of its components.

---

cardiac arrhythmia -- any variation from the normal rhythm or rate of the heart beat.

Tachycardia -- Abnormally rapid heartbeat, usually with a HEART RATE above 100 beats per minute for adults. Tachycardia accompanied by disturbance in the cardiac depolarization (cardiac arrhythmia) is called tachyarrhythmia.

Immediate hypersensitivity -- Hypersensitivity reactions which occur within minutes of exposure to challenging antigen due to the release of histamine which follows the antigen-antibody reaction and causes smooth muscle contraction and increased vascular permeability.

Hypersensitivity -- Altered reactivity to an antigen, which can result in pathologic reactions upon subsequent exposure to that particular antigen.

Excessive use of adrenergic aerosols is potentially dangerous.

Fatalities have been reported following excessive use of metaproterenol sulfate as with other sympathomimetic inhalation preparations, and the exact cause is unknown.

Cardiac arrest was noted in several cases.Paradoxical bronchoconstriction with repeated excessive administration has been reported with sympathomimetic agents.Patients should be advised to contact their physician in the event that they do not respond to their usual dose of sympathomimetic amine aerosol.

The following US Branded drugs contain Metaproterenol Sulfate

---

ALUPENT -- BOEHRINGER INGELHEIM PHARMACEUTICALS INC

PROMETA -- MURO PHARMACEUTICAL INC

ALUPENT -- BOEHRINGER INGELHEIM