Patterns of natural health product use at an outpatient heart function clinic.

Background: Natural health product (NHP) use is common among Canadians, but the NHPs used by outpatients with cardiovascular conditions such as atrial fibrillation and heart failure have not been identified. Objectives: Describe NHP use among outpatient cardiac patients, assess drug interactions and their potential implications and determine NHP documentation by health care providers. Methods: Telephone interviews were conducted by the main researcher with patients who attended the Cardiac Clinics at the Royal Columbian Hospital. Medication reconciliation was performed to elicit information regarding NHP use and clinic charts were used to supplement demographic information. Results: There were 119 successful interviews. Most patients were approximately 65 years old and male, were diagnosed with atrial fibrillation, had 2 to 3 queried comorbidities and took 2 cardiovascular medications. It was found that 62% of patients use NHPs, and 239 individual NHPs were identified. The most common NHPs used were vitamins and minerals (63%), especially vitamin D (13%), multivitamins (8%) and omega-3s (8%). Interactions between cardiac medications and NHPs occurred in 86% of patients. NHP use was completely documented by health care providers in 24% of patients. Conclusion: NHP use is common among patients who attend outpatient cardiac clinics. Interactions between NHPs and cardiovascular medications are prevalent and may carry specific individual patient risks. NHP documentation by health care providers is often incomplete.