Use of herbal supplements and potential for herb-drug interactions among older adults in southeast Idaho

Purpose: This cross-sectional study examined the use of herbal supplements (HS) and potential for herb-drug interactions among older adults in southeast Idaho.

Methods: A written questionnaire on HS was developed and pilot tested. Data were collected from a convenience sample of 112 adults, aged 60 to 92, participating in congregate meal programs in southeast Idaho. Frequency distributions and percentages were calculated to examine the use of HS and potential for herb-drug interactions. The Mann-Whitney U t-test compared perceived safety of HS between users and nonusers.

Results: Of the 112 participants who completed the written questionnaire, 55% (n=62) reported they had used HS in the past. The top five most commonly used HS were garlic, aloe vera, echinacea, ginger, and ginkgo biloba. Participants reported that print media, television, family, and friends, were the most common sources of HS information. Herbal supplement users disclosed their use of HS to family (89%) and friends (77%) most frequently, while fewer disclosed their use to a doctor (51%), nurse (21%), pharmacist (12%), or dietitian (10%). Ninety-five percent of those using HS and 75% of nonusers reported that they believed most or some HS were safe. There was a significant difference in perceived safety between HS users and nonusers (p<.001). The majority of HS users reported use of prescription medication(s) and aspirin. Among HS users, 45% used garlic and aspirin, 25% used ginger and aspirin, and 18% used ginkgo biloba and aspirin.

Conclusion: Since the potential for herb-drug interactions exist, health professionals should act as a HS resource and inform patients about HS use and concerns.