Nitroglycerin Prescription and Potency in Patients Participating in Exercise-Based Cardiac Rehabilitation

PURPOSE: Current guidelines call for nitroglycerin to be prescribed in patients with coronary heart disease, including those with stable angina and those recovering from acute coronary syndromes and myocardial infarction. These patients are at risk for coronary events, and nitroglycerin may be required to treat acute symptoms of myocardial ischemia. Nitroglycerin rapidly loses potency when stored improperly, compromising effectiveness. Previous studies indicate that patients frequently fail to store nitroglycerin properly. Accordingly, pharmacists routinely advise patients to renew nitroglycerin tablets every 6 months. The purpose of this study was to determine frequency of prescription of nitroglycerin and the relationship to potency in patients participating in exercise-based cardiac rehabilitation programs. METHODS: A Survey was performed over a 3-month period of 617 patients enrolled in 9 exercise-based cardiac rehabilitation centers in New York, Michigan, and Rhode Island. Patient data were evaluated according to cardiac diagnoses and the use of sublingual nitroglycerin. RESULTS: A total of 380% of patients did not have a prescription for nitroglycerin. Patients with potentially subpotent nitroglycerin tablets included 23% whose prescription was older than 1 year and an additional 15% whose tablets were between 6 and 12 months old. CONCLUSIONS: The prescription of nitroglycerin is frequently omitted in patients with coronary heart disease. Those who are prescribed nitroglycerin frequently carry a potentially subpotent medication. Education is necessary for both patients and physicians. The findings have implications for counseling patients who are enrolled in exercise-based cardiac rehabilitation programs.