Subcutaneous epinephrine is now rarely used in the management of acute exacerbations in asthma. However, it should never be used in the patient with significant cardiovascular or hypertensive disease. When used in combination with aminophylline in acutely ill asthmatics, it may provoke fatal ventricular arrhythmias. Although selective beta 2 -agonists do not have significant cardiac side effects, they may result in an increase in cardiac output due to peripheral vasodilation and a reflex increase in cardiac output. This altered hemodynamic may be significant in those with ischemic heart disease.
Theophylline is a potent inotrope and thus increases myocardial oxygen demand.
Additionally, theophylline may cause arrhythmias in acutely ill asthmatics. In addition, the drug metabolism may be altered by co-existing liver disease. Therefore, this drug is best avoided in those with cardiac co-morbidities. Cromolyn and anticholinergic agents, such as ipratropium, have minimal if any, cardiac side effects. These drugs are thus particularly useful in patients with cardiac disease.