From the Guidelines
Aminophylline infusion is a second-line treatment for severe, acute asthma exacerbations that don't respond adequately to first-line therapies like inhaled beta-agonists, anticholinergics, and systemic corticosteroids. The recommended loading dose is 5 mg/kg administered intravenously over 20 minutes, followed by a maintenance infusion of 1 mg/kg/h, as stated in the guidelines by the British Thoracic Society 1.
Key Considerations
- Prior to initiating therapy, check if the patient is already taking theophylline products, as this would necessitate dose adjustment.
- Therapeutic serum levels should be maintained, requiring regular monitoring.
- Common side effects include tachycardia, nausea, vomiting, headache, and seizures, particularly at higher serum concentrations.
- Aminophylline works as a bronchodilator by inhibiting phosphodiesterase, which increases intracellular cAMP levels, relaxing bronchial smooth muscle.
- It also has anti-inflammatory properties and enhances diaphragmatic contractility.
- Dose reduction is necessary in patients with liver disease, heart failure, or the elderly, and drug interactions are common with medications like cimetidine, erythromycin, and certain fluoroquinolones which can increase aminophylline levels.
Clinical Context
While effective, aminophylline has largely been superseded by safer bronchodilators with fewer side effects and drug interactions, as noted in the expert panel report 3 (EPR-3) guidelines for the diagnosis and management of asthma 1. However, in the context of severe, acute asthma exacerbations, aminophylline infusion remains a viable option, particularly when first-line treatments are insufficient, as suggested by the British Thoracic Society nebulizer project group 1.
Patient Management
In managing asthma, it's crucial to consider the stepwise approach for managing asthma, evaluating asthma control, and adjusting treatment accordingly, as outlined in the EPR-3 guidelines 1. For patients with chronic lung disease of infancy and childhood, bronchodilators, including methylxanthines like theophylline, can be beneficial in improving pulmonary function, but their use should be carefully monitored due to potential side effects and the need for strict dose control 1.
From the FDA Drug Label
Inhaled beta-2 selective agonists and systemically administered corticosteroids are the treatments of first choice for management of acute exacerbations of asthma The results of controlled clinical trials on the efficacy of adding intravenous theophylline to inhaled beta-2 selective agonists and systemically administered corticosteroids in the management of acute exacerbations of asthma have been conflicting Most studies in patients treated for acute asthma exacerbations in an emergency department have shown that addition of intravenous theophylline does not produce greater bronchodilation and increases the risk of adverse effects In contrast, other studies have shown that addition of intravenous theophylline is beneficial in the treatment of acute asthma exacerbations in patients requiring hospitalization, particularly in patients who are not responding adequately to inhaled beta-2 selective agonists
The role of aminophylline infusion in the management of asthma is as an add-on therapy in certain cases. It may be beneficial in patients requiring hospitalization who are not responding adequately to inhaled beta-2 selective agonists, but it does not produce greater bronchodilation and increases the risk of adverse effects in patients treated in an emergency department 2.
- Key points:
- Not a first-line treatment for acute asthma exacerbations
- May be considered as add-on therapy in hospitalized patients not responding to initial treatment
- Increases the risk of adverse effects in some cases
From the Research
Role of Aminophylline in Asthma Management
- Aminophylline is a methylxanthine derivative that has been used in the treatment of asthma, particularly in severe, acute cases 3, 4, 5, 6, 7.
- The evidence suggests that aminophylline may be effective in improving lung function and reducing symptoms in patients with acute asthma, especially when combined with other treatments such as beta-agonists 3, 5.
- However, the use of aminophylline in asthma management is not without controversy, and some studies have raised questions about its efficacy and potential adverse effects 4, 7.
Comparison with Other Treatments
- Aminophylline has been compared to other treatments such as beta-agonists, and the evidence suggests that it may be as effective or even superior in some cases 5.
- However, other studies have found no significant difference between aminophylline and other treatments, and some have raised concerns about the potential for adverse effects 4, 7.
Specific Patient Populations
- In children, aminophylline may be an alternative to intravenous infusion of beta-agonists, heliox, or magnesium sulfate administration in cases where respiratory fatigue is developing 4.
- In adults, the use of aminophylline is not recommended due to its potential adverse effects 4.