NHP used in sample | Adverse events reported for that NHP in the literaturea |
---|---|
Cranberry (Vaccinium macrocarpon) | More than one litre daily may cause kidney stones [31]. (Note: In this sample, cranberry pills were used and did not exceed this level) |
Dehydroepiandrosterone (DHEA) or 5-Dehydro-epiandrosterone (5-DHEA) | People with mood disorders may experience mania, irritability, and sexual inappropriateness [32–35] |
Devil’s Claw (Harpago-phytum procumbens) | Mild gastrointestinal upset, hypotension, diarrhea, loss of taste, anorexia, headache, and tinnitus [32–34]. May interact with warfarin; one case report of purpura [36] |
Dong Quai (Angelica sinensis), Chinese angelica | In a cross-sectional survey (n = 1818), one case was identified as a potential significant interaction between dong quai and anticoagulant/antiplatelet agents [37] |
Echinacea (Echinacea angustifolia, Echinacea pallida, Echinacea purpurea) | Gastrointestinal upset and rashes; in rare cases, has been associated with allergic reactions that may be severe [38]. May interact with amoxicillin [39] |
Evening Primrose Oil (Oenothera biennis) | Case reports of seizures in patients with/without known seizure disorders [40, 41]. In cross-sectional survey (n = 1818), two cases of potential significant interactions with anticoagulant/antiplatelet agents identified [37] |
Feverfew (Tanacetum parthenium; syn. Chrysanthemum parthenium (L.) Pers., Pyrethrum parthenium Sm.) | Gastrointestinal upset [42, 43], nervousness, insomnia [44], and possible allergic responses in those sensitive to chrysanthemums, daisies, or marigolds. Potential cross-reactivity with other members of the Compositae family [45]. In cross-sectional survey (n = 1818), two cases of potential clinically significant interactions with anticoagulant/antiplatelet agents identified [37]. |
Flaxseed (common flax, linseed, Linum usitatissimum) | Rarely, flaxseed (not oil form) has caused gastrointestinal distress [46–50]. A double-blind placebo-controlled trial suggested there may be increased episodes of mania and hypomania in people with bipolar disorder [46] |
Garlic (Allium sativum) | Breath and body odour, and allergic reactions [51]. Excess use associated with spontaneous epidural hematoma [52]. Potential reactions include bleeding and hypoglycemia (likely not clinically significant) [53]. In cross-sectional survey (n = 1818), 25 cases of potential clinically significant interactions with anticoagulant/antiplatelet agents identified [37] |
Ginkgo (Ginkgo biloba) | Surveillance studies (> 10,000 people), found 1.69% incidence of symptoms such as headache and gastrointestinal complaints [54]. Bleeding indicated in a few case reports [55]. May cause allergic hypersensitivity, including Stevens-Johnson syndrome [56–58]. In cross-sectional survey of 1818 patients, 20 cases of potential clinically significant interactions with anticoagulant/antiplatelet agents identified [37]. Infrequent mild gastrointestinal discomfort has been reported when Ginkgo is taken with selective serotonin reuptake inhibitors (SSRIs) [59]. May interact with thiazides [60, 61], and nifedipine [62, 63] |
Ginseng (American, Asian, Chinese, Korean red; Panax ginseng, Panax spp. including P. ginseng and P. quinquefolius) | Long-term use of Panax and American ginseng associated with skin rash, itching, diarrhea, sore throat, loss of appetite, excitability, anxiety, depression, or insomnia [53, 64]. Few reports of headache, fever, dizziness/vertigo, blood pressure changes, chest pain, difficult menstruation, heart palpitations, leg swelling, nausea, vomiting, manic episodes in bipolar disorder, or Stevens-Johnson syndrome (may have been due to product contaminants) [53]. High intake of American ginseng may result in hypoglycemia in people with/without diabetes [65]. May interact with anticoagulants/antiplatelets [66, 67], diabetes medications [37], digoxin [68], estrogenic agents [69–71], furosemide [72], monoaminergic agents [73–75], nifedipine [76] |
Ginseng (American, Asian, Chinese, Korean red; Panax ginseng, Panax spp. including P. ginseng and P. quinquefolius) | Long-term use of Panax and American ginseng associated with skin rash, itching, diarrhea, sore throat, loss of appetite, excitability, anxiety, depression, or insomnia [53, 64]. Few reports of headache, fever, dizziness/vertigo, blood pressure changes, chest pain, difficult menstruation, heart palpitations, leg swelling, nausea, vomiting, manic episodes in bipolar disorder, or Stevens-Johnson syndrome (may have been due to product contaminants) [53]. High intake of American ginseng may result in hypoglycemia in people with/without diabetes [65]. May interact with anticoagulants/antiplatelets [66, 67], diabetes medications [37], digoxin [68], estrogenic agents [69–71], furosemide [72], monoaminergic agents [73–75], nifedipine [76] |
Melatonin (N-acetyl-5-methoxytryptamine) | May worsen depression and irritability. Sedative medications (CNS depressants) and benzodiazepines interact with melatonin [77] |
Omega-3 Fatty Acids, Alpha-Linolenic Acid | Caution indicated for those with diabetes as may increase blood glucose, at risk of bleeding, or with high LDL levels [78–85]. May interact with anticoagulants/antiplatelets [80, 86–90] |
Valerian (Valeriana officinalis) | Mild impairments in concentration, processing, fatigue (less pronounced than with benzodiazepines) [91–95], dizziness, and headache [96, 97]. Drug “hangover” and “withdrawal” effect has been reported with high doses [96]. Delirium, ameliorated by benzodiazepines, indicated in one case report [98]. Some develop a “paradoxical reaction” leading to nervousness, and use for longer than 2 months may result in insomnia [53]. Rare reports of hepatotoxicity with some preparations that include valerian [99] but may have been due to other components. May interact with CNS depressants [91, 92, 100]. In cross-sectional survey (n = 1818), 15 cases of potential clinically significant interactions with sedatives identified [37]. One case of SSRI use and valerian (with alcohol) indicated mental status changes [101] |