Evaluation of presence of aspirin-related warnings with willow bark.

BACKGROUND: The dietary supplement willow bark, also known simply as willow, contains salicylates that may present a safety risk to people. Current regulations do not require willow bark to include any cautions on its label. OBJECTIVE: To evaluate the absence or presence of label warnings related to salicylates contained in willow bark to ascertain whether a potentially dangerous lack of information exists. METHODS: The label of each willow supplement and willow-containing product was assessed for the presence or absence of 3 warnings: (1) aspirin allergy/sensitivity, (2) use of anticoagulants or "blood thinners," and (3) children with flu-like symptoms or Reye's syndrome. Products from pharmacies and health food stores were targeted and their labels analyzed. A compilation of the identified products was used to conduct a similar evaluation of warnings from their Web sites. RESULTS: A total of 58 willow bark-containing and 12 single-ingredient willow bark products were assessed. Of the 70 products evaluated, only 8.6% listed a warning. The warning regarding aspirin sensitivity was present on 4.3%, Reye's syndrome was 2.9%, and interactions with anticoagulants/"blood thinners" was 4.3%. One product was labeled as aspirin-free. Percentages were lower on Web sites. CONCLUSIONS: There is a dearth of information regarding potential safety risks on the labels of willow bark and willow bark-containing products. Combination products containing willow bark may pose a greater danger to at-risk patients based on their sheer volume. Counseling of patients who take dietary supplements can improve the situation; however, it may ultimately take improved requirements for dietary supplement labeling to fully address this problem.

Anaphylactic reaction to a dietary supplement containing willow bark.

OBJECTIVE: To report a case of anaphylaxis resulting from the use of a willow bark-containing dietary supplement in a patient with a history of an aspirin allergy. CASE SUMMARY: A 25-year-old white woman presented to the emergency department of a community teaching hospital with anaphylaxis requiring epinephrine, diphenhydramine, methylprednisolone, and volume resuscitation to which she responded favorably. Medication history revealed that she had ingested 2 capsules of Stacker 2 (NVE Pharmaceuticals, Newton, NJ), a dietary supplement promoted for weight loss, prior to experiencing her initial symptoms. Among other active ingredients, this product contains willow bark. Of significance is that this patient also reported a history of allergy to acetylsalicylic acid. No other causes for anaphylaxis were identified. She continued to receive routine supportive care and the remaining hospital course was uncomplicated. DISCUSSION: Dietary supplements, including herbal products, are used by many individuals who consider them to be inherently safe despite limited regulatory oversight by the Food and Drug Administration. While there may be value to specific botanical ingredients, a potential for adverse effects also exists. The popular product consumed by our patient is used for weight loss and contains willow bark, a source of salicylates. Based on the Naranjo probability scale, it is probable that this case of anaphylaxis was due to this dietary supplement. CONCLUSIONS: The use of any willow bark-containing dietary supplement may present a risk of anaphylactic reaction to patients with a history of allergy to salicylates. Clinicians need to recognize the potential for adverse effects from dietary supplements.