Foxglove

Foxglove/Drug Interactions:

  • NoteNote: Agents that may interact with digoxin may also interact with foxglove.
  • Alzheimer's agentsAlzheimer's agents: Foxglove contains ferulic acid and choline, which has been shown to prevent cognitive defects (17; 18). The effects with antidementia agents are not understood.
  • AnalgesicsAnalgesics: Foxglove contains caffeic acid, chlorogenic acid, ferulic acid, and gallic acid, all of which have been shown to have analgesic effects (56; 57; 32). Thus, there is the potential for additive effects.
  • AnestheticsAnesthetics: Foxglove contains benzoic acid, which has been shown to have anesthetic effects in laboratory research (58; 59). Thus, there is the potential for additive effects.
  • AntacidsAntacids: Antacids may interfere with absorption and result in reduced effectiveness of foxglove.
  • AntiarthriticsAntiarthritics: Foxglove contains luteolin, which inhibits collagenase activity in vitro (16). Thus, there is the potential for additive effects with antiarthritic agents. Sulfasalazine, an agent that may be used for arthritis, may interfere with absorption and result in reduced effectiveness of foxglove.
  • Antiasthma drugsAntiasthma drugs: Foxglove contains gallic acid, which has antiasthmatic effects in vitro (11). Gallic acid has also been shown to prevent bronchial hyperreactivity in animal study (60).
  • Anticoagulants and antiplateletsAnticoagulants and antiplatelets: Foxglove contains citric acid, apigenin, caffeic acid, and ferulic acid, all of which have demonstrated anticoagulant or antiaggregant effects in various models (12; 13; 14; 15). Thus, there is the potential for additive effects.
  • AntidepressantsAntidepressants: According to animal study, caffeic acid, which may be found in foxglove, has antidepressant effects (19). Thus, there is the potential for additive effects.
  • AntidiabeticsAntidiabetics: Foxglove contains chlorogenic acid, which has hypoglycemic effects in an animal model (20). Theoretically, concurrent use of foxglove with antidiabetic agents may cause additive glucose lowering.
  • AntifungalsAntifungals: According to secondary sources, benzoic acid, which may be found in foxglove, has antiyeast effects. Thus, there is the potential for additive effects.
  • AntihistaminesAntihistamines: Foxglove contains gallic acid, which has been shown to inhibit histamine release and proinflammatory cytokine production in mast cells (11). Thus, there is the potential for additive effects.
  • AntihypertensivesAntihypertensives: The effects of foxglove on blood pressure are not clear. It has been reported to both increase and decrease blood pressure (30; 27; 28). Foxglove contains acetylcholine, apigenin, and choline, which have hypotensive effects in animal models (27; 28). Theoretically, foxglove may interfere with other agents that affect blood pressure.
  • Anti-inflammatoriesAnti-inflammatories: Foxglove contains ferulic acid, luteolin, and gallic acid, which have demonstrated anti-inflammatory effects in an animal model (32; 33; 34). In vitro, gallic acid inhibits histamine release and proinflammatory cytokine production (11). Sulfasalazine, an anti-inflammatory agent, may interfere with absorption and result in reduced effectiveness of foxglove.
  • AntilipemicsAntilipemics: Foxglove contains ferulic acid, which has exhibited hypolipidemic effects in an animal model (26). Cholestyramine, a bile acid sequestrant, may interfere with absorption and result in reduced effectiveness of foxglove.
  • Antineoplastic sAntineoplastic s: Foxglove contains caffeic acid, gallic acid, chlorogenic acid, ferulic acid, apigenin, and luteolin, which have demonstrated anticancer effects in vitro (61; 62; 22; 63; 64; 65). These drugs may also interfere with absorption and result in reduced effectiveness of foxglove.
  • Antiulcer agentsAntiulcer agents: Foxglove contains chlorogenic acid, which has displayed an inhibitory effect on gastric ulcers (66). The effects with other antiulcer agents are not well understood.
  • AntiviralsAntivirals: Foxglove contains apigenin, luteolin, gallic acid, caffeic acid, digitoxin, ferulic acid, gitoxin, and chlorogenic acid, which have reported antiviral effects (67; 68; 69). According to in vitro study, apigen, luteolin, and gallic acid have displayed inhibitory human immunodeficiency virus (HIV) and hepatitis C activity (67; 68).
  • Beta BlockersBeta Blockers: Concurrent use of ( blockers with foxglove may cause additive cardiac effects on atrioventricular (AV) node conduction and result in advanced or complete heart block.
  • Calcium channel blockersCalcium channel blockers: Concurrent use of calcium channel blockers with foxglove may cause additive cardiac effects on AV node conduction and result in advanced or complete heart block. Additionally, foxglove contains luteolin, which has calcium antagonistic effects (70). According to secondary sources, foxglove also contains caffeic acid, which has calcium antagonistic effects.
  • Calcium saltsCalcium salts: Concurrent use of foxglove and calcium may have additive or synergistic effects, which may cause serious arrhythmias.
  • Cardiac glycosidesCardiac glycosides: Theoretically, concomitant use of foxglove, which contains cardiac glycosides, and the cardiac glycoside digitalis may increase the risk for cardiac glycoside toxicity.
  • Cardiovascular agentsCardiovascular agents: Digitalis toxicity may cause cardiac arrhythmias. Cardiac function should be monitored with concurrent use of foxglove with other cardiovascular agents.
  • CharcoalCharcoal: Charcoal may be used to bind some cardiac glycosides for removal from the body (71).
  • CNS stimulantsCNS stimulants: According to secondary sources, foxglove contains chlorogenic acid, which has CNS stimulatory and depressive effects. The effects with CNS stimulants are not well understood.
  • Dermatologic agentsDermatologic agents: Foxglove contains luteolin, which inhibits collagenase activity in vitro (16). Thus, there is the potential for additive effects with dermatologic agents.
  • DiphenoxylateDiphenoxylate: Diphenoxylate may increase digoxin absorption and drug levels by decreasing gut motility.
  • Diuretics, potassium sparingDiuretics, potassium sparing: Concomitant use of foxglove and potassium-sparing diuretics may increase the risk of toxicity. Patients using these types of diuretics should be advised to consume extra potassium in the diet.
  • Diuretics, thiazideDiuretics, thiazide: Concomitant use of foxglove and thiazide diuretics may increase the risk of toxicity. Patients using these types of diuretics should be advised to consume extra potassium in the diet.
  • EstrogensEstrogens: Foxglove contains apigenin and luteolin, which have estrogenic effects in vitro (73; 74). Thus, there is the potential for additive effects.
  • Fertility agentsFertility agents: According to secondary sources, foxglove contains coumaric acid, which has antifertility effects. The effects with antifertility agents are not well understood.
  • Heart rate-regulating agentsHeart rate-regulating agents: Foxglove is considered an antiarrhythmic agent and may cause additive cardiac effects when used with other antiarrhythmic agents.
  • Hypertensive drugsHypertensive drugs: The effects of foxglove on blood pressure are not clear. It has been reported to both increase and decrease blood pressure (30; 27; 28). Foxglove contains acetylcholine, apigenin, and choline, which have hypotensive effects in animal models (27; 28). Theoretically, foxglove may interfere with other agents that affect blood pressure.
  • ImmunosuppressantsImmunosuppressants: In vitro, gallic acid inhibits histamine release and proinflammatory cytokine production (11). Saponins have immunological adjuvant effects in animal models (31). Foxglove may alter the effects of immunosuppressive agents.
  • LaxativesLaxatives: Laxatives like senna may cause potassium loss. In an elderly man using digitalis, congestive heart failure occurred due to increased toxicity following the use of an herbal laxative (75). Concurrent use of aloe with foxglove may cause hypokalemia and digoxin toxicity.
  • MacrolidesMacrolides: Macrolide antibiotics may inactivate digoxin by bacterial metabolism in the lower intestine and result in toxicity.
  • MagnesiumMagnesium: Based on digitalis studies, foxglove may reduce levels of magnesium (76; 77). Thus, magnesium supplements may counteract this effect.
  • MetoclopramideMetoclopramide: Metoclopramide may interfere with absorption and result in reduced effectiveness of foxglove.
  • Neurologic agentsNeurologic agents: Foxglove toxicity may cause dizziness, stupor, confusion, convulsions, delirium, hallucinations, and decreased consciousness. Foxglove contains apigenin, which has antagonistic effects on GABA and NMDA channels in vitro (72). The effects of foxglove with neurologic agents are not well understood.
  • PropanthelinePropantheline: Propantheline may increase digoxin absorption and drug levels by decreasing gut motility.
  • RifampinRifampin: Rifampin may reduce levels of foxglove, especially in patients with renal dysfunction, by increasing hepatic metabolism and induction of P-glycoprotein (78).
  • SedativesSedatives: Foxglove contains apigenin, which has antagonistic effects on GABA and NMDA channels in vitro (72). Thus, there is the potential for additive effects.
  • Skeletal muscle relaxantsSkeletal muscle relaxants: According to secondary sources, apigenin, gallic acid, and luteolin, which are found in foxglove, have myorelaxant effects.
  • SuccinylcholineSuccinylcholine: The use of succinylcholine with foxglove may increase the risk of arrhythmias by causing shifts of potassium from muscle cells.
  • SympathomimeticsSympathomimetics: The use of foxglove with sympathomimetics may increase the risk of arrhythmia.
  • TetracyclinesTetracyclines: Tetracycline antibiotics may inactivate digoxin by bacterial metabolism in the lower intestine and result in toxicity.
  • Thyroid hormonesThyroid hormones: Thyroid hormones may decrease the effectiveness of foxglove. Foxglove also contains apigenin, caffeic acid, and chlorogenic acid, which have antithyroid effects (29).
  • VasodilatorsVasodilators: Apigenin inhibits nitric oxide synthesis in vitro (79). In rat thoracic aorta, luteolin induces vasorelaxation (80). The effects of foxglove with vasodilators are not well understood.
  • Foxglove/Herb/Supplement Interactions:

  • Activated charcoalActivated charcoal: Charcoal may be used to bind some cardiac glycosides for removal from the body (71).
  • Alzheimer's agentsAlzheimer's agents: Foxglove contains ferulic acid and choline, which has been shown to prevent cognitive defects (17; 18). The effects with antidementia agents are not understood.
  • AnalgesicsAnalgesics: Foxglove contains caffeic acid, chlorogenic acid, ferulic acid, and gallic acid, all of which have been shown to have analgesic effects (56; 57; 32). Thus, there is the potential for additive effects.
  • AnestheticsAnesthetics: Foxglove contains benzoic acid, which has been shown to have anesthetic effects in laboratory research (58; 59). Thus, there is the potential for additive effects.
  • AntacidsAntacids: Antacids may interfere with absorption and result in reduced effectiveness of foxglove.
  • Antiarrhythmics. Antiarrhythmics: Foxglove is considered an antiarrhythmic agent and may cause additive cardiac effects when used with other antiarrhythmic agents.
  • AntiarthriticsAntiarthritics: Foxglove contains luteolin, which inhibits collagenase activity in vitro (16). Thus, there is the potential for additive effects with antiarthritic agents.
  • AntiasthmaticsAntiasthmatics: Foxglove contains gallic acid, which has antiasthmatic effects in vitro (11). Gallic acid has also been shown to prevent bronchial hyperreactivity in animal study (60).
  • AntibacterialsAntibacterials: Macrolide and tetracycline antibiotics may inactivate digoxin by bacterial metabolism in the lower intestine and result in toxicity.
  • Anticoagulants and antiplateletsAnticoagulants and antiplatelets: Foxglove contains citric acid, apigenin, caffeic acid, and ferulic acid, all of which have demonstrated anticoagulant or antiaggregant effects in various models (12; 13; 14; 15). Thus, there is the potential for additive effects.
  • Antidepressant agents, monoamine oxidase inhibitors (MAOIs)Antidepressant agents, monoamine oxidase inhibitors (MAOIs): Foxglove contains caffeic acid, which has antidepressant effects in an animal model (19). Thus, there is the potential for additive effects.
  • Antidepressants, selective serotonin reuptake inhibitors (SSRIsAntidepressants, selective serotonin reuptake inhibitors (SSRIs): Foxglove contains caffeic acid, which has antidepressant effects in an animal model (19). Thus, there is the potential for additive effects.
  • AntifungalsAntifungals : According to secondary sources, benzoic acid, which may be found in foxglove, has antiyeast effects. Thus, there is the potential for additive effects.
  • AntihistaminesAntihistamines : Foxglove contains gallic acid, which has been shown to inhibit histamine release and proinflammatory cytokine production in mast cells. (11). Thus, there is the potential for additive effects.
  • Anti-inflammatoriesAnti-inflammatories: Foxglove contains ferulic acid, luteolin, and gallic acid, which have demonstrated anti-inflammatory effects in an animal model (32; 33; 34). In vitro, gallic acid inhibits histamine release and proinflammatory cytokine production (11).
  • AntilipemicsAntilipemics : Foxglove contains ferulic acid, which has demonstrated hypolipidemic effects in an animal model (26). Cholestyramine, a bile acid sequestrant, may interfere with absorption and result in reduced effectiveness of foxglove.
  • AntineoplasticsAntineoplastics : Foxglove contains caffeic acid, gallic acid, chlorogenic acid, ferulic acid, apigenin, and luteolin, which have anticancer effects in vitro (61; 62; 22; 63; 64; 65). These agents may also interfere with absorption and result in reduced effectiveness of foxglove.
  • Antiulcer agentsAntiulcer agents : Foxglove contains chlorogenic acid, which has displayed an inhibitory effect on gastric ulcers (66). The effects with other antiulcer agents are not well understood.
  • AntiviralsAntivirals : Foxglove contains apigenin, luteolin, gallic acid, caffeic acid, digitoxin, ferulic acid, gitoxin, and chlorogenic acid, which have reported antiviral effects (67; 68; 69). According to in vitro study, apigen, luteolin, and gallic acid have displayed inhibitory HIV and hepatitis C activity (67; 68).
  • Calcium Calcium : Concurrent use of foxglove and calcium may have additive or synergistic effects that may cause serious arrhythmias.
  • Cardiac glycosidesCardiac glycosides: Theoretically, concomitant use of foxglove, which contains cardiac glycosides, and the cardiac glycoside digitalis may increase the risk for cardiac glycoside toxicity.
  • Cardioactive herbsCardioactive herbs: Digitalis toxicity may cause cardiac arrhythmias. Cardiac function should be monitored with concurrent use of foxglove with other herbs/supplements that affect the heart.
  • CarobCarob: Concurrent use of carob and foxglove may increase concentrations of foxglove and result in toxicity. The exact mechanism for this interaction is unknown (81).
  • Dermatologic agentsDermatologic agents: Foxglove contains luteolin, which inhibits collagenase activity in vitro (16). Thus, there is the potential for additive effects with dermatologic agents.
  • DiureticsDiuretics: Concomitant use of foxglove and potassium-depleting herbs/supplements may increase the risk of toxicity. Patients using these types of diuretics should be advised to consume extra potassium in the diet.
  • Fertility agentsFertility agents : According to secondary sources, foxglove contains coumaric acid, which has antifertility effects. The effects with antifertility agents are not well understood.
  • GossypolGossypol: Theoretically, gossypol may reduce the efficacy of foxglove as well as increase the risk of foxglove toxicity due to potassium depletion (82).
  • HypertensivesHypertensives: The effects of foxglove on blood pressure are not clear. It has been reported to both increase and decrease blood pressure (30; 27; 28). Foxglove contains acetylcholine, apigenin, and choline, which have hypotensive effects in animal models (27; 28). Theoretically, foxglove may interfere with other agents that affect blood pressure.
  • HypoglycemicsHypoglycemics : Foxglove contains chlorogenic acid, which has demonsrated hypoglycemic effects in an animal model (20). Theoretically, concurrent use of foxglove with antidiabetic agents may cause additive glucose lowering.
  • HypotensivesHypotensives: The effects of foxglove on blood pressure are not clear. It has been reported to both increase and decrease blood pressure (30; 27; 28). Foxglove contains acetylcholine, apigenin, and choline, which have hypotensive effects in animal models (27; 28). Theoretically, foxglove may interfere with other agents that affect blood pressure.
  • ImmunosuppressantsImmunosuppressants: In vitro, gallic acid inhibits histamine release and proinflammatory cytokine production (11). Saponins have immunological adjuvant effects in animal models (31). Foxglove may alter the effects of immunosuppressive agents.
  • LaxativesLaxatives: Laxatives like senna and aloe may cause potassium loss. In an elderly man using digitalis, congestive heart failure occurred due to increased toxicity following the use of a herbal laxative (75). Concurrent use of aloe with foxglove may cause hypokalemia and digoxin toxicity.
  • LicoriceLicorice: In an elderly man using digitalis, congestive heart failure occurred due to increased toxicity following the use of a licorice-containing herbal laxative (75). Thus, concomitant use of foxglove and licorice may increase the risk for toxicity.
  • MagnesiumMagnesium: Based on digitalis studies, foxglove may reduce levels of magnesium (76; 77). Thus, magnesium supplements may counteract this effect.
  • Neurologic agentsNeurologic agents: Foxglove toxicity may cause dizziness, stupor, confusion, convulsions, delirium, hallucinations, and decreased consciousness. Foxglove contains apigenin, which has antagonistic effects on GABA and NMDA channels in vitro (72). The effects of foxglove with neurologic agents are not well understood.
  • PhytoestrogensPhytoestrogens: Foxglove contains apigenin and luteolin, which have estrogenic effects in vitro (73; 74). Thus, there is the potential for additive effects.
  • SedativesSedatives: Foxglove contains apigenin, which has antagonistic effects on GABA and NMDA channels in vitro (72). Thus, there is the potential for additive effects.
  • StimulantsStimulants: According to secondary sources, foxglove contains chlorogenic acid, which has CNS stimulatory and depressive effects. The effects with CNS stimulants are not well understood.
  • SympathomimeticsSympathomimetics: The use of foxglove with sympathomimetics may increase the risk of arrhythmia.
  • Thyroid agentsThyroid agents: Thyroid agents may decrease the effectiveness of foxglove. Foxglove also contains apigenin, caffeic acid, and chlorogenic acid, which have antithyroid effects (29).
  • VasodilatorsVasodilators: Apigenin inhibits nitric oxide synthesis in vitro (79). In rat thoracic aorta, luteolin induces vasorelaxation (80). The effects of foxglove with vasodilators are not well understood.
  • Foxglove/Food Interactions:

  • Carob fiberCarob fiber: Concurrent use of carob fiber and foxglove may increase concentrations of foxglove and result in toxicity (81). The exact mechanism for this interaction is unknown (81).
  • Foxglove/Lab Interactions:

  • Blood glucoseBlood glucose: Foxglove contains chlorogenic acid, which has demonsrated hypoglycemic effects in an animal model (20).
  • Coagulation panelCoagulation panel: Foxglove contains citric acid, apigenin, caffeic acid, and ferulic acid, all of which have demonstrated anticoagulant or antiaggregant effects in various models (12; 13; 14; 15).
  • Electrocardiogram (ECG)Electrocardiogram (ECG): Digoxin may prolong the PR interval and depress the ST segment on the electrocardiogram (ECG). False positive ST-T changes may also occur on the ECG during exercise testing.
  • Lipid profileLipid profile: Foxglove contains ferulic acid, which has exhibited hypolipidemic effects in an animal model (26).
  • MagnesiumMagnesium: Based on digitalis studies, foxglove may reduce levels of magnesium (76; 77).
  • PotassiumPotassium: Based on digitalis studies, foxglove may reduce levels of potassium (83).
  • Sex hormonesSex hormones: Foxglove contains apigenin and luteolin, which have estrogenic effects in vitro (73; 74).
  • Thyroid hormonesThyroid hormones: Thyroid hormones may decrease the effectiveness of foxglove. Foxglove also contains apigenin, caffeic acid, and chlorogenic acid, which have antithyroid effects (29).