Begs the question on how careful we might have to be with supplements in general.
Results
Ten brands of galantamine supplements and 11 brands of generic galantamine medications were included. Generic drugs were labeled as containing 4, 8, and 12 mg of galantamine per tablet or capsule. The actual content of galantamine in the generic drugs ranged from 97.5% to 104.2% of the labeled content (Table 1). No generic drugs were contaminated with microorganisms.
Dietary supplements were labeled as containing 4, 6, 8, and 12 mg of galantamine per serving. The actual quantity of galantamine in the dietary supplements ranged from less than 2% to 110% of the labeled quantity.
**Three supplements (30%) were contaminated with Bacillus cereus sensu stricto–encoding enterotoxin genes associated with diarrheal illness **(Table 2). The contaminated supplements contained 60%, 62%, and 75% of the labeled quantity of galantamine. All 11 generic drugs (100%) and 1 supplement (10%) contained a quantity of galantamine that was within 10% of the quantity declared on the label.
Discussion
Galantamine sold as generic drugs was accurately labeled and free of contamination, in contrast to galantamine sold as dietary supplements. The detected quantities of B cereus ss may suggest lack of appropriate quality control during manufacturing. However, adverse health effects would not be expected with these quantities of bacteria. For patients with Alzheimer disease, use of galantamine supplements instead of generic galantamine may adversely affect their care. Furthermore, the sale of inaccurately labeled galantamine supplements promoted for nonspecific memory and other cognitive problems is concerning given the lack of proven efficacy, potential drug-drug interactions, and adverse effects, including nausea, vomiting, dizziness, bradycardia, and syncope.6
The study has limitations. First, products were purchased at only 1 time point and the results may not be generalizable to galantamine supplements currently available given that manufacturers can introduce, reformulate, or withdraw supplement products without notifying the FDA. Second, whether the results are generalizable to other supplement ingredients, such as niacin, potassium, and iron, which are also available as either dietary supplements or generic drugs, is unknown.
The laws regulating dietary supplements should be reformed such that the FDA has enforcement mechanisms to ensure that dietary supplement labels accurately reflect their contents. Meanwhile, clinicians should query patients with memory concerns about the use of dietary supplements and advise patients not to use galantamine supplements.
