From the Guidelines
Metaproterenol is a bronchodilator medication used to treat asthma, bronchitis, emphysema, and other breathing disorders, belonging to the class of drugs called beta-2 adrenergic agonists, which work by relaxing the smooth muscles in the airways, making breathing easier. According to the most recent study 1, metaproterenol can cause an increase in heart rate, which could lead to myocardial ischemia in patients with cardiac disease. The medication is typically administered via an inhaler or nebulizer solution, with common dosages being 2-3 puffs every 3-4 hours as needed for the inhaler form, or 0.2-0.3 mL of a 5% solution in 2-3 mL of saline via nebulizer.
Some key points to consider when using metaproterenol include:
- Side effects may include tremors, nervousness, headache, increased heart rate, and palpitations 1
- The medication works quickly, usually within minutes, by stimulating beta-2 receptors in the lungs, which triggers the relaxation of bronchial smooth muscle and reduces airway resistance
- Patients should be aware that overuse can lead to decreased effectiveness and potentially worsening symptoms, so it's essential to use it exactly as prescribed
- Those with heart conditions, high blood pressure, diabetes, or thyroid disorders should use metaproterenol with caution and inform their healthcare provider about all medications they are taking to avoid potential interactions 1
It's also important to note that metaproterenol has been compared to other medications, such as epinephrine, in the treatment of acute asthma, and the results show that there were no deaths or intubations recorded in the final outcomes of any study 1. However, the most recent and highest quality study 1 provides the most relevant information for clinical practice.
From the FDA Drug Label
Combined therapy produced significant additional improvement in FEV1 and FVC On combined therapy, the median duration of 15% improvement in FEV1 was 5 to 7 hours, compared with 3 to 4 hours in patients receiving a beta agonist alone. Metaproterenol is a beta adrenergic bronchodilator solution, used in combination with ipratropium bromide inhalation solution for the treatment of bronchospasm associated with chronic obstructive pulmonary disease (COPD) 2.
- It is used to produce bronchodilation
- The combination of metaproterenol and ipratropium bromide has been shown to produce significant improvements in pulmonary function compared to either agent alone 2.
From the Research
Definition and Uses of Metaproterenol
- Metaproterenol is a beta-adrenergic agonist used for the relief of bronchospasm in conditions such as asthma and chronic obstructive pulmonary disease (COPD) 3, 4, 5, 6, 7.
- It is available in various forms, including inhalation solutions and oral formulations, and can be administered via different routes, such as inhalation or orally 4, 7.
Efficacy and Safety
- Studies have shown that metaproterenol is effective in providing bronchodilation in patients with COPD and asthma, with significant improvements in forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) 3, 5, 6.
- The combination of metaproterenol with other bronchodilators, such as ipratropium bromide, has been shown to offer a potential therapeutic advantage in patients with COPD, with improved bronchodilation and duration of action 3, 6.
- Metaproterenol has been associated with side effects, such as tremor, palpitation, and increased pulse rate, particularly when administered orally 4, 7.
Comparison with Other Treatments
- Metaproterenol has been compared to other treatments, such as ipratropium bromide and theophylline, in patients with COPD and asthma, with varying results 5, 6, 7.
- Inhaled metaproterenol has been shown to be superior to oral theophylline in improving spirometric variables and breathlessness rating in patients with chronic airflow obstruction 7.