Herb_Interaction_Chart (PDF, 1mb)
This is the corresponding references for the Herbs on the Hill Herb-Drug Interaction Chart. The co-ordinates can be seen on the chart itself, and can be referenced here, sorted by Drug then Herb. The link above provides access to the chart itself as a PDF (1mb).
| DRUG | HERB | INTERACTION |
|---|---|---|
| 1 | 31 | Mucilages in marshmallow may reduce the absorption of pharmaceutical medications. This is of particular importance in drug that have a narrow therapeutic index (NTI). Separate doses by a minimum of 2 hours. |
| 1 | 41 | Mucilages in slippery elm may reduce the absorption of pharmaceutical medications. This is of particular importance in drug that have a narrow therapeutic index (NTI). Separate doses by a minimum of 2 hours. |
| 2 | 28 | Kava may theoretically increase the CNS depressant activity of codeine and morphine [1]. Close patient monitoring and medical supervision is advised. |
| 3 | 30 | Concurrent administration of Quinidine and Convallaria may enhance both drug effects and side effects [8] Lily-of-the-valley is currently a scheduled (S4) medicine. Avoid concurrent use. |
| 4 | 3 | Andrographis has shown ex-vivo antiplatelet activity [5]. Andrographolide has been shown to inhibit PAF induced platelet aggregation [1] |
| 4 | 10 | Case reports suggest Dan Shen can increase INR and prolong APTT [5]. In-vitro studies have shown Dan Shen to possess anticoagulant and fibrinolytic activity [7]. Avoid concurrent use. |
| 4 | 11 | A case of purpura was reported in a patient taking concurrent Devil’s claw and warfarin [5]. Due to lack of other medications, doses and duration of use in this case report the clinical significance is questionable. Monitor closely. |
| 4 | 12 | Concurrent use may increase risk of bleeding as Dong Quai may potentiate effects of warfarin [5, 8]. IV administration of Dong Quai caused prothrombin time to be significantly longer [8] Uncertain clinical significance for oral dosage forms of this herb. Monitor closely. |
| 4 | 14 | Evening primrose oil contains gamma-linoleic acid which can affect prostaglandin synthesis leading to inhibition of platelet aggregation [1] CAUTION: Avoid high doses of the oil with concurrent use. Interaction is theoretical and of uncertain clinical significance |
| 4 | 16 | Case reports have suggested that garlic may increase INR in patients on warfarin [2]. Caution should be exercised with patients taking any anticoagulant medication [10] Avoid high doses of the herb (>4g/day equiv fresh). |
| 4 | 17 | Ginger has been shown to inhibit platelet aggregation in high dose. Daily doses of 2g/day of ginger should not be exceeded in pregnancy [9]. CAUTION: Avoid high dose (>10g/day) unless under medical supervision [1] , whereas Mills & Bone suggests >4g/day dried ginger requires supervision [5] Monitor closely or avoid concurrent use. |
| 4 | 18 | Isolated case reports have reported increased bleeding tendency for both warfarin and aspirin [5]. Recent clinical studies show Ginkgo has no significant impact on warfarin [1]. Monitor closely. |
| 4 | 19 | Inhibits platelet aggregation in in-vitro and in-vivo tests [1]. A case reports suggest it can lower INR in a previously stabilised patient [8]. Monitor closely or avoid concurrent use. |
| 4 | 22 | Case report suggested increase in INR [5]. CAUTION: Avoid high doses of the herb. Monitor closely. |
| 4 | 23 | Grape seed is rich in polyphenolics, and has the ability to inhibit platelet aggregation [12] CAUTION: With high doses of the herb. Interaction is theoretical and of uncertain clinical significance. |
| 4 | 24 | In-vitro and in-vivo antiplatelet activity has been established [1, 8] Interaction is of uncertain clinical significance. |
| 4 | 25 | In-vitro and clinical data suggest that Guggul increased coagulation and prothrombin time, decreased platelet adhesiveness, increased fibrinolytic activity and inhibited platelet aggregation [7, 13] CAUTION: Unlike Myrrh, use cautiously due to suggestive evidence. |
| 4 | 29 | In-vitro and in-vivo tests suggest glycyrrhizin inhibits prothrombin and Isoliquiritigenin inhibits platelet aggregation [1]. CAUTION: With high doses of this herb. Interaction is of uncertain clinical significance. |
| 4 | 42 | Reduced blood levels of warfarin have been noted in case reports from concurrent administration of Hypericum preparations [1, 2, 4, 5, 14]. St. John’s Wort is a known inducer of CYT P450 enzymes causing increase drug metabloism. Avoid concurrent use. |
| 4 | 43 | Due to St Mary’s thistle having inhibitive effects on the CYT P450 system, a potential increase in drug levels is possible [1]. Interaction is of uncertain clinical significance. Monitor patient closely. |
| 4 | 44 | Curcumin, a key constituent of Turmeric, has been shown to inhibit platelet aggregation in-vitro [15]. CAUTION: With doses greater than 15g per day [5] |
| 4 | 46 | Clinical study observed Willow to have antiplatelet activity [5] Higher doses than 240mg of salicin per day may have a more significant effect [1]. Monitor patient closely in higher dosage. |
| 5 | 9 | In-vivo test on rats found that celery juice prolonged the action of phenobarbitone [1]. Interaction is of uncertain clinical significance. |
| 5 | 18 | In-vivo animal studies and 2 case reports suggest a potential interaction is possible with concurrent use of Ginkgo causing reduced drug effects [5]. Monitor patient. |
| 5 | 28 | Isolated methysticin reversibly blocked epileptiform activity in various in-vitro seizure models, showing anticonvulsant activity [2]. Interaction is of uncertain clinical significance. |
| 5 | 42 | St John’s Wort is known to induce the CYT P450 system, resulting in the increased metabolism of multiple drugs. This may lead to reduced drug effectiveness and poor clinical outcomes. No known adverse events have been reported with concurrent use of phenytoin or other anticonvulsants and St. John’s Wort use [9] |
| 5 | 43 | St Mary’s thistle has been shown to inhibit CYT P450 3A4, therefore reducing drug metabolism. This may lead to increased blood levels of carbamazepine (a drug with a narrow therapeutic index (NTI)) and associated adverse effects [1] |
| 6 | 42 | Potential for serotonergic syndrome with concurrent use [1, 2, 5]. Avoid if possible, or use only under close medical supervision. St. John’s Wort may decrease tricyclics drug plasma levels, and also may increase available serotonin [1] Avoid if possible, or use only under close medical supervision. |
| 7 | 42 | A clinical study demonstrated the potential for St. John’s Wort to decrease drug levels [5] Monitor patient. |
| 8 | 29 | High dose administration for longer than 4-6 weeks may result in pseudoaldosteronism and BP increase [5] Avoid long term use at doses > 100mg/day of glycyrrhizin [5] |
| 8 | 36 | Animal studies have shown the oil of peppermint to increase felodipine bioavailability [1]. Monitor patient as drug dosage requirement may need modification |
| 9 | 14 | Case reports suggest that the oil of Evening primrose may reduce seizure threshold and reduce drug effectiveness in patients with schizophrenia being administered phenothiazines [1]. Avoid concurrent use until safety profile is established [1]. |
| 10 | 16 | Garlic has demonstrated in a clinical study to reduce serum levels of saquinivir and drug effectiveness, resulting in poor clinical outcomes [1]. Avoid concurrent use |
| 10 | 42 | Case report suggestive that the effective dose was lowered. Monitor patient and be prepared to shorten treatment or reduce dose [5] St John’s Wort is known to reduce drug levels via the CYTP450 and P-gp systems, resulting in reduced drug effectiveness and poor clinical outcomes [1, 5]. St John’s Wort is known to reduce drug levels via the CYTP450 and P-gp systems, resulting in reduced drug effectiveness and poor clinical outcomes [1, 5]. Avoid concurrent use. |
| 11 | 1 | In-vivo studies demonstrated a potentiation of phenobarbitone-induced sleeping time [1]. Interaction may be beneficial, but is of uncertain clinical significance and requires medical supervision. Use caution. |
| 11 | 28 | Potential to increase sedative effects [1]. Interaction may be beneficial, but is of uncertain clinical significance and requires medical supervision. Drug dosage modification may be required. Use caution. |
| 11 | 34 | Potential to increase sedative effects [1]. Interaction may be beneficial, but is of uncertain clinical significance and requires medical supervision. Use caution. |
| 11 | 42 | St John’s Wort is known to induce the CYT P450 system and P-gp [1], resulting in reduced drug levels and poor clinical outcomes. Avoid concurrent use |
| 11 | 45 | Potential to increase sedative effects [1]. Interaction may be beneficial, but is of uncertain clinical significance and requires medical supervision. Use caution. |
| 12 | 28 | The use of Kava to ease symptoms of benzodiazepine withdrawal exists if done under medical supervision [1]. Potential beneficial interaction. Drug dosage modification may be required. |
| 12 | 34 | Potential to increase sedative effects [1]. Interaction may be beneficial, but is of uncertain clinical significance and requires medical supervision. |
| 12 | 42 | A clinical study demonstrated reduced drug levels with concurrent Midazolam and St John’s Wort use [5]. Avoid concurrent use unless under medical supervision. Drug dosage modification may be required. |
| 13 | 42 | St John’s Wort is known to induce the CYT P450 system and P-gp. Case reports show herb can decrease serum levels [1, 2, 4, 5]. Avoid concurrent use. |
| 14 | 2 | Oral use of Aloe long-term may deplete potassium levels which lower the threshold for Digoxin toxicity [1, 5] Avoid concurrent long-term use unless under medical supervision |
| 14 | 7 | Avoid excessive use of laxative herbs as enhanced digoxin toxicity caused by lowered potassium levels is possible [5]. Avoid concurrent long-term use unless under medical supervision |
| 14 | 20 | Siberian ginseng has the potential to interfere with digoxin assay [5], and may produce false positive test results [1] Consult patients medical practitioner. |
| 14 | 24 | Long-term use of high dose Guarana can deplete potassium levels which lowers the threshold for Digoxin toxicity [1] Avoid concurrent long-term use unless under medical supervision |
| 14 | 27 | In-vitro and in-vivo studies demonstrate Hawthorn as having a positively inotropic and chronotropic activity [1]. Interaction may be beneficial, but is of uncertain clinical significance and requires medical supervision. |
| 14 | 29 | Long-term use of high dose Licorice can deplete potassium levels which lowers the threshold for Digoxin toxicity [1, 5] Avoid concurrent use. |
| 14 | 30 | Concurrent administration of Digoxin and Convallaria may enhance drug effects and side effects [8] Avoid concurrent use. |
| 14 | 40 | Avoid excessive use of laxative herbs as enhanced digoxin toxicity caused by lowered potassium levels is possible [5]. Avoid concurrent long-term use unless under medical supervision |
| 14 | 42 | St John’s Wort is known to induce the CYT P450 system and P-gp [1], resulting in the increased metabolism of Digoxin. A clinical study demonstrated that St John’s Wort significantly decreased serum levels of Digoxin within 10 days of concurrent use [1] Avoid concurrent use [2, 4, 8] |
| 15 | 20 | Co-administration may increase drug tolerance and improve patient immune function [1] Interaction may be beneficial, but is of uncertain clinical significance and requires medical supervision. |
| 15 | 39 | Rosemary inhibits P-glycoprotein so may affect the bioavailability of Pgp substrates BRAUN 2007. |
| 15 | 42 | Clinical studies have shown St. John’s Wort may decrease drug levels resulting in poor clinical outcomes [5]. Avoid concurrent use. Clinical studies have shown St. John’s Wort may decrease drug levels of irinotecan, resulting in poor clinical outcomes [5]. Avoid concurrent use. |
| 15 | 43 | Research suggests that St. Mary’s thistle and cisplatin may reduce toxicity effects yet enhance antitumour activity [1]. Interaction may be beneficial and require drug dosage modification under medical supervision. |
| 16 | 19 | Based on the pharmacological activity of Korean ginseng, the potential to increase stimulating effects exists. Interaction is of uncertain clinical significance |
| 16 | 24 | Based on the pharmacological activity of Guarana, the potential to increase stimulating effects exists. |
| 17 | 42 | Breakthrough bleeding has been reported in 12 cases which is suggestive of reduced drug effectiveness [1]. Reports from Britain and Sweden suggest unwanted pregnancies have occurred with concurrent use [9] Avoid use with low-dose OCP (<50mcg of oestrogen) if possible [1, 2] |
| 20 | 2 | Oral use of Aloe long-term may deplete potassium levels [5]. Monitor patient. |
| 20 | 7 | Oral use of Cascara long-term may deplete potassium levels [5]. Monitor patient. |
| 20 | 24 | Guarana may theoretically increase dieresis whilst also decreasing hyptotensive activity [1]. Interaction is of uncertain clinical significance |
| 20 | 29 | Long-term use of high dose Licorice can deplete potassium levels [1, 5] Avoid doses >100mg glycyrrhizin/day for periods > 2 weeks [1] Monitor patient. |
| 20 | 40 | Oral use of Senna long-term may deplete potassium levels [5]. Monitor patient. |
| 21 | 28 | Dopamine antagonistic effects have been reported [1]. Avoid concurrent use unless under medical supervision. |
| 22 | 28 | Based on the pharmacological activity of Kava, concurrent use may theoretically increase sedation [1] Interaction is theoretical and of uncertain clinical significance |
| 22 | 42 | St. John’s Wort may decreased serum levels of methadone [1]. Avoid concurrent use |
| 24 | 42 | Breakthrough bleeding has been reported in 12 cases which is suggestive of reduced drug effectiveness [1]. Reports from Britain and Sweden suggest unwanted pregnancies have occurred with concurrent use [9] Avoid use with low-dose OCP (<50mcg of oestrogen) if possible [1, 2] |
| 25 | 5 | Based on the pharmacological activity of Bladderwrack, the potential to interact with preparations containing thyroid hormones exists [9] |
| 25 | 6 | Based on the pharmacological activity of Bugleweed, the potential to interact with preparations containing thyroid hormones exists [9]. Avoid concurrent use. Bugleweed may also interfere with thyroid diagnostic procedures that utilise radioactive isotopes [9] |
| 25 | 32 | Based on the pharmacological activity of Motherwort, the potential to interact with preparations containing thyroid hormones exists [9]. Avoid concurrent use. |
| 26 | 3 | Andrographis has shown hypoglycaemic activity in-vivo comparable to metformin[1]. Interaction is theoretical and of uncertain clinical significance. Monitor patients BSL. |
| 26 | 15 | Fenugreek reduces BSL but the exact mechanism of action is unclear [8]. Monitor patients BSL. Drug dose modification may be required. |
| 26 | 21 | Galegine, an alkaloid from Goat’s Rue, has been shown to have hypoglycaemic properties. Use cautiously and monitor patients BSL regularly [5]. Drug dose modification may be required. |
| 26 | 26 | Gymnema has a well documented hypoglycaemic activity causing the enhanced reduction of blood glucose. Use cautiously and monitor patients BSL regularly [5]. Drug dose modification may be required. |
| 26 | 33 | Two furanosesquiterpenes isolated from Myrrh exhibited hypoglycaemic activity in-vivo in normal and diabetic models [9] Interaction is theoretical and of uncertain clinical significance. Monitor patients BSL. |
| 27 | 42 | St. John’s Wort increases the metabolism of simvastatin, and therefore drug dosage modification may be required [1] |
| 28 | 3 | Due to the known immunostimulant activity of andrographis, a theoretical potential for reduced drug effectiveness exists. Interaction is of uncertain clinical significance. |
| 28 | 4 | Due to the known immunostimulant activity of astragalus, a theoretical potential for reduced drug effectiveness exists. Interaction is of uncertain clinical significance. |
| 28 | 8 | Due to the known immunostimulant activity of cat’s claw, a theoretical potential for reduced drug effectiveness exists. The manufacturers of products standardised to pentacyclic oxindole alkaloids (POAs) warn against the use of Cats Claw in patients receiving immuneosuppressive medications [5] Interaction is of uncertain clinical significance. |
| 28 | 13 | Due to the known immunostimulant activity of echinacea, a theoretical potential for reduced drug effectiveness exists [5]. Interaction is of uncertain clinical significance. |
| 28 | 16 | Due to the known immunostimulant activity of garlic [1], a theoretical potential for reduced drug effectiveness exists. Interaction is of uncertain clinical significance. |
| 28 | 19 | Due to the known immunostimulant activity of Korean ginseng, a theoretical potential for reduced drug effectiveness exists. Interaction is of uncertain clinical significance. |
| 28 | 20 | Due to the known immunostimulant activity of Siberian ginseng, a theoretical potential for reduced drug effectiveness exists. Interaction is of uncertain clinical significance. |
| 28 | 35 | Due to the known immunostimulant activity of Pau d’Arco, a theoretical potential for reduced drug effectiveness exists. Interaction is of uncertain clinical significance. |
| 28 | 36 | Peppermint oil has been shown in animal studies to increase the oral bioavailability of cyclosporin [1]. Interaction is of uncertain clinical significance. |
| 28 | 37 | Due to the known immunostimulant activity of pokeroot a theoretical potential for reduced drug effectiveness exists. Interaction is of uncertain clinical significance. |
| 28 | 42 | St John’s Wort is known to induce the CYT P450 system and P-gp. Case reports suggest it may reduce drug effectiveness [5]. Avoid concurrent use. St John’s Wort is known to induce the CYT P450 system and P-gp. Herb decreases tacrolimus serum levels [1]. Avoid concurrent use |
| 28 | 43 | Research suggests that St. Mary’s thistle and cisplatin may reduce toxicity effects yet enhance antitumour activity [1]. Interaction may be beneficial and require drug dosage modification under medical supervision. |
| 29 | 27 | Clinical studies have shown the ability for tannins and other polyphenolics to reduce Iron absorption. Separate doses of Iron by 2 hours. Caution in patients suffering from anaemia |
| 29 | 39 | Clinical studies have shown the ability for tannins and other polyphenolics to reduce Iron absorption. Separate doses of Iron by 2 hours. Caution in patients suffering from anaemia |
| 30 | 38 | A case report suggests decreased lithium concentrations with concurrent administration of Psyllium [5], resulting in reduced drug effectiveness. Ensure dosage is separated by a minimum of 2 hours. |
| 32 | 9 | Celery contains psoralens, however, does not seem to be photosensitising even after large oral doses. May increase the risk of phototoxicity with concurrent PUVA therapy [1] Interaction is of uncertain clinical significance. |
| 32 | 42 | Hypericin may increase sensitivity to UV radiation [1]. Use caution, especially in preparations containing high hypericin content. Interaction is of uncertain clinical significance. |
REFERENCES
[1] Braun L, & Cohen, M. Herbs and Natural Supplements: An Evidence-Based Guide. Marrickville NSW: Elsevier Australia 2005.
[2] ESCOP Monographs. 2nd ed. Exeter European Scientific Cooperative on Phytotherapy 2003.
[3] Wilt T, Ishani A, Mac Donald R, Rutks I, Stark G. Pygeum africanum for benign prostatic hyperplasia. Cochrane Database of Systematic Reviews 2008(3):1-20.
[4] WHO monographs on selected medicinal plants. Geneva World Health Organisation 2003.
[5] Mills S, & Bone, K. The Essential Guide to Herbal Safety. St Louis, Missouri USA: Churchill Livingstone 2005.
[6] Shanmuganayagam D, Beahm MR, Osman HE, Krueger CG, Reed JD, Folts JD. Grape Seed and Grape Skin Extracts Elicit a Greater Antiplatelet Effect When Used in Combination than When Used Individually in Dogs and Humans. Journal of Nutrition. 2002 December 1, 2002;132(12):3592-8.
[7] Bone K. Clinical Applications of Ayurvedic and Chinese Herbs: Monographs for the Western Herbal Practitioner. Warwick QLD Australia: Phytotherapy Press 1996.
[8] Gruenwald J, Brendler, T & Jaenicke, C. Physicians Desk Reference for Herbal Medicines. 3rd ed. Montvale New Jersey USA: Thomson PDR 2004.
[9] Bone K. A Clinical Guide to Blending Liquid Herbs: Herbal Formulations for the Individual Patient. St Louis, Missouri USA: Churchill Livingston 2003.
[10] WHO monographs on selected medicinal plants Geneva: World Health Organization 1999.
[11] Yun-Choi. H, Kim. J, Lee. J. Potential inhibitors of platelet aggregation from plant sources, III. Journal of Natural Products. 1987 Nov-Dec;50(6):1059-64.
[12] Shanmuganayagam D, Beahm MR, Osman HE, Krueger CG, Reed JD, Folts JD. Grape Seed and Grape Skin Extracts Elicit a Greater Antiplatelet Effect When Used in Combination than When Used Individually in Dogs and Humans. Journal of Nutrition. 2002 December 1, 2002;132(12):3592-8.
[13] Satyavati GV. Gum guggul (Commiphora mukul): the success story of an ancient insight leading to a modern discovery. The Indian Journal Of Medical Research. 1988;87:327-35.
[14] Blumenthal M, Brinckmann J, Wollschlaeger B. The ABC Clinical Guide to Herbs. 1st ed. Austin Texas: American Botanical Council 2003.
[15] Mills S, Bone, K. Principles and Practice of Phytotherapy. London UK: Churchill Livingstone 2000.
[16] Mills S, Bone, K. The Essential Guide To Herbal Safety. Missouri USA: Elsevier 2005.