Medicago sativa
Alfalfa/Drug Interactions:
Anticoagulants and antiplateletsAnticoagulants and antiplatelets: Alfalfa has been reported to contain vitamin K (44; 45), and therefore may reduce the effects of anticoagulant agents that rely on depletion of vitamin K. Antidiabetic agentsAntidiabetic agents: Based on limited case report data (6) and animal research (26), alfalfa may lower blood glucose levels, and may have additive effects when used with other hypoglycemic agents (25). AntifungalsAntifungals: Alfalfa may possess antifungal properties (46), and therefore, may have additive affects when taken concomitantly with antifungals. G2, 2-beta-hydroxy-3-beta-O- (beta-D-glucopyranosyl)-delta 12-oleanene-23, 28-dionic acid has been isolated from alfalfa roots and has been shown in vitro to possess a high degree of activity against Cryptococcus neoformans (MIC 2mcg/mL) (47). G2 exhibits activity against a wide range of yeast strains, and appears to induce lethal ion leakage from yeast cells (48). Medicagenic acid, hederagenin glycosides, and soyasapogenols may contribute to the antifungal actions of alfalfa, including against Aspergillus niger, Candida albicans, and Candida tropicalis (3). Antilipemic agentsAntilipemic agents: Alfalfa may lower total cholesterol, low-density lipoprotein (LDL), and triglyceride concentrations, based on two human case series and animal data (19; 5; 49; 50); alfalfa may therefore have additive effects when used with other cholesterol-lowering medications. Calcium saltsCalcium salts: Mean serum calcium levels decreased significantly in a case series of 15 patients taking 40g of heat prepared alfalfa seed three times daily for eight weeks (5). Alfalfa may increase intracellular Ca+2 levels, based on an in vitro study of the alfalfa constituent L-canavanine (51). Chlorpromazine (Thorazine?)Chlorpromazine (Thorazine?): Chlorpromazine has been reported to increase drug-induced photosensitivity when taken in combination with alfalfa.ContraceptivesContraceptives: Alfalfa has been reported to contain coumestrol and other constituents that may possess estrogenic properties (7; 8). Interactions with other hormonal therapies are not known. Disulfiram (Antabuse?)Disulfiram (Antabuse?): Many tinctures/liquid extracts contain high levels of alcohol, and may cause nausea or vomiting when taken with disulfiram (Antabuse?).EstrogensEstrogens: Alfalfa has been reported to contain coumestrol and other constituents that have estrogenic properties (7; 8). Hormonal agentsHormonal agents: Alfalfa has been reported to contain coumestrol and other constituents that may possess estrogenic properties (7; 8). Interactions with other hormonal therapies are not known. ImmunosuppressantsImmunosuppressants: The alfalfa constituent L-canavanine, an amino acid, has been associated in animals and humans with the development of a lupus-like syndrome, or exacerbation of systemic lupus erythematosus (SLE) (10; 52; 53). In vitro, alfalfa appears to act on CD8 (-) Leu8 (+) T cells to regulate antibody synthesis and proliferation (51). L-canavanine may exert an inhibitory effect on CD8 T cells (53), and may also exert effects on mononuclear cells (52). The mechanism of action remains unknown. Metronidazole (Flagyl?)Metronidazole (Flagyl?): Many tinctures/liquid extracts contain high levels of alcohol and may cause nausea or vomiting when taken with metronidazole (Flagyl?).Photosensitizing agentsPhotosensitizing agents: Based on laboratory study, chlorpromazine may increase drug-induced photosensitivity when taken in combination with alfalfa (9). Furthermore, there have been several reports of photosensitivity in cattle from ingestion of alfalfa (54; 55; 56; 57; 58). Potassium saltsPotassium salts: Alfalfa may lower serum potassium concentrations, based on a human case report (28). Thyroid hormonesThyroid hormones: Immunoreactive thyrotropin-releasing hormone-like material has been found in alfalfa, although its biological action is unknown (4). Warfarin (Coumadin?)Warfarin (Coumadin?): Alfalfa is reported to contain vitamin K (44; 45), and therefore may reduce the effects of vitamin K dependent anticoagulant medications. Alfalfa/Herb/Supplement Interactions:
Anticoagulants and antiplateletsAnticoagulants and antiplatelets: Alfalfa has been reported to contain vitamin K (44; 45), and therefore may reduce the effects of anticoagulant agents that rely on depletion of vitamin K. AntifungalsAntifungals: Alfalfa may possess antifungal properties (46), and therefore, may have additive affects when taken concomitantly with antifungals. G2, 2-beta-hydroxy-3-beta-O- (beta-D-glucopyranosyl)-delta 12-oleanene-23, 28-dionic acid has been isolated from alfalfa roots and has been shown in vitro to possess a high degree of activity against Cryptococcus neoformans (MIC 2mcg/mL) (47). G2 exhibits activity against a wide range of yeast strains, and appears to induce lethal ion leakage from yeast cells (48). Medicagenic acid, hederagenin glycosides, and soyasapogenols may contribute to the antifungal actions of alfalfa, including against Aspergillus niger, Candida albicans, and Candida tropicalis (3). AntilipemicsAntilipemics: Alfalfa may lower total cholesterol, low-density lipoprotein (LDL), and triglyceride concentrations, based on two human case series and animal data (19; 5; 49; 50); alfalfa may therefore have additive effects when used with other cholesterol-lowering agents. CalciumCalcium: Mean serum calcium levels decreased significantly in a case series of 15 patients taking 40g of heat prepared alfalfa seed three times daily for eight weeks (5). Alfalfa may increase intracellular Ca+2 levels, based on an in vitro study of the alfalfa constituent L-canavanine (51). Hormonal herbs and supplementsHormonal herbs and supplements: Alfalfa has been reported to contain coumestrol and other constituents that have estrogenic properties (7; 8). HypoglycemicsHypoglycemics: Based on limited case report data (6) and animal research (26), alfalfa may lower blood glucose levels, and may have additive effects when used with other hypoglycemic agents (25). ImmunostimulantsImmunostimulants: The alfalfa constituent L-canavanine, an amino acid, has been associated in animals and humans with the development of a lupus-like syndrome, or exacerbation of systemic lupus erythematosus (SLE) (10; 52; 53). In vitro, alfalfa appears to act on CD8 (-) Leu8 (+) T cells to regulate antibody synthesis and proliferation (51). L-canavanine may exert an inhibitory effect on CD8 T cells (53), and may also exert effects on mononuclear cells (52). The mechanism of action remains unknown. ImmunosuppressantsImmunosuppressants: The alfalfa constituent L-canavanine, an amino acid, has been associated in animals and humans with the development of a lupus-like syndrome, or exacerbation of systemic lupus erythematosus (SLE) (10; 52; 53). In vitro, alfalfa appears to act on CD8 (-) Leu8 (+) T cells to regulate antibody synthesis and proliferation (51). L-canavanine may exert an inhibitory effect on CD8 T cells (53), and may also exert effects on mononuclear cells (52). The mechanism of action remains unknown. IronIron: Alfalfa and other fibers have been shown in vitro to bind iron, therefore reducing its absorption (59). PhotosensitizersPhotosensitizers: Based on laboratory study, chlorpromazine may increase drug-induced photosensitivity when taken in combination with alfalfa (9). Furthermore, there have been several reports of photosensitivity in cattle from ingestion of alfalfa (54; 55; 56; 57; 58) PhytoestrogensPhytoestrogens: Alfalfa has been reported to contain coumestrol and other constituents that have estrogenic properties (7; 8). PotassiumPotassium: Alfalfa may lower serum potassium concentrations, based on a human case report (28). Thyroid agentsThyroid agents: Immunoreactive thyrotropin-releasing hormone-like material has been found in alfalfa, although its biological action is unknown (4). Vitamin EVitamin E: Alfalfa contains saponins, which may interfere with the absorption or activity of vitamin E. In addition, it has been postulated that vitamin E may potentiate the effects of L-canavanine, a component of alfalfa associated with the development of lupus-like syndrome, or exacerbation of lupus (13). Data are limited in this area. Vitamin KVitamin K: Alfalfa contains vitamin K (44; 45), and when taken with other sources of vitamin K, it may additively reduce the efficacy of anticoagulants such as warfarin. Alfalfa/Food Interactions:
Vitamin K-containing foodsVitamin K-containing foods: Foods containing vitamin K, such as green leafy vegetables, may have additive effects with alfalfa (which also contains vitamin K) in reducing the efficacy of anticoagulants such as warfarin (44; 45). Alfalfa/Lab Interactions:
Blood glucoseBlood glucose: Based on limited case report data and animal research, alfalfa may lower blood glucose levels (6; 25; 26). Coagulation panelCoagulation panel: Alfalfa contains vitamin K (44; 45), and when taken with other sources of vitamin K, it may additively reduce the efficacy of anticoagulants such as warfarin. Lipid panelLipid panel: Alfalfa may lower total cholesterol, low-density lipoprotein (LDL), and triglyceride concentrations (19; 5; 49; 50). Serum calciumSerum calcium: Mean serum calcium levels decreased significantly in a case series of 15 patients taking 40g of heat prepared alfalfa seed three times daily for eight weeks (5). Alfalfa may increase intracellular Ca+2 levels, based on an in vitro study of the alfalfa constituent L-canavanine (51). Serum potassiumSerum potassium: Alfalfa may lower serum potassium concentrations, based on a human case report (28). Uric acidUric acid: Alfalfa may increase serum urate levels (5).