Zingiber officinale
Ginger/Drug Interactions:
AnalgesicsAnalgesics: In animal and human research, ginger monotherapy and combination therapy has demonstrated analgesic effects (137; 260; 149; 1; 215; 261; 262; 217). AntacidsAntacids: According to secondary sources, the ginger rhizome (underground stem) may increase stomach acid production. Therefore, it may interfere with antacids, sucralfate (Carafate?), H2 antagonists, or proton pump inhibitors. In contrast, other in vitro and animal research has revealed gastroprotective properties (263; 264). Also, 6-shogaol has inhibited intestinal motility in intravenous preparations and facilitated gastrointestinal motility in oral preparations. Ginger extract, zingiberene, and 6-gingerol have been observed to afford cytoprotection against chemically induced ulceration in rats (263; 264), and ginger extract has been reported to inhibit the growth of Helicobacter pylori in vitro (56). However, clinical research indicated a significant increase in the exfoliation of gastric surface epithelial cells following the consumption of 6g or more of ginger (265). In human research, ginger monotherapy and combination therapy (Tongyan spray) have demonstrated effects on lower esophageal sphincter function (200), swallowing (266), gastric emptying (199), and stomach hormone levels (261). Antiarrhythmic agentsAntiarrhythmic agents: Arrhythmias are theoretically possible at high doses, based on in vitro and in vivo studies showing that components of ginger activate Ca2+-ATPase and have dose-dependent positive inotropic effects (142). In an equivalence study comparing ginger and vitamin B6 for nausea, arrhythmia occurred in both groups but was minor and not significant (3). Antiarthritic agentsAntiarthritic agents: According to expert opinion, inhibition of prostaglandin and thromboxane formation by human platelets and the subsequent production of lipid peroxides have been proposed as possible mechanisms by which ginger might provide relief of rheumatoid arthritis symptoms (267). AntiasthmaticsAntiasthmatics: In humans, acupoint sticking coadministered with combination ginger medication cakes or ginger-partition moxibustion improved symptoms of bronchial asthma and self-reported quality of life (268; 269). AntibioticsAntibiotics: According to animal research, ginger may increase the absorption and plasma half-life, and significantly decrease the elimination rate constant and clearance, of metronidazole (270). In vitro, ginger and some of its constituents may have antibacterial activity (162; 163; 164; 165; 166; 167; 168; 169; 170; 171; 172; 173; 174; 175; 176; 177; 178; 179; 180). Anticoagulants and antiplateletsAnticoagulants and antiplatelets: In theory, since ginger has been observed to inhibit thromboxane synthetase and because decreased platelet aggregation has been reported in clinical trials, concurrent use of ginger with agents that predispose patients to bleeding may enhance their effect and increase the risk of bleeding (271; 272; 185; 186). Concurrent use of ginger increased the risk of self-reported bleeding in patients taking warfarin (273). One observational study found that frequent (more than four times weekly) dietary consumption of herbs was associated with an international normalized ration (INR) outside of optimal therapeutic range (274). According to a human case report, the INR rose after initiating therapy with ginger and warfarin (214). It is unclear to what extent ginger was responsible for this rise in the INR, although another case report indicated a possible anticoagulant interaction with concurrent use of ginger (247), and the results from one clinical trial have suggested that ginger lacks effect on the pharmacokinetic and pharmacodynamic profile of warfarin and subsequently on the clotting status of healthy individuals (275). Antidepressants: selective serotonin reuptake inhibitors (SSRIs)Antidepressants: selective serotonin reuptake inhibitors (SSRIs): In vitro, ginger may antagonize serotonin receptors (161) and theoretically may interfere with SSRIs. Antidiabetic agentsAntidiabetic agents: In animal research, treatment of streptozotocin (STZ)-induced type 1 diabetic rats with Zingiber officinale significantly increased insulin levels and decreased fasting glucose levels and also decreased serum cholesterol, serum triglyceride, and blood pressure (135; 136; 137; 138; 139; 140). Theoretically, due to its purported hypoglycemic effects, ginger may interfere with diabetes therapy, potentially requiring dosing adjustments (134). AntiemeticsAntiemetics: Ginger, administered as both monotherapy and combination therapy (KSS formula), has been shown to have antiemetic effects in clinical trials (209; 3; 4; 17; 276; 7; 19; 208; 210; 5; 8; 9; 11; 201; 12; 13; 150; 197; 277; 278; 14) and in animal research (279). Additive effects may occur when taken concomitantly with other antiemetics. Antifungal agentsAntifungal agents: In vitro, ginger and some of its constituents exerted antifungal effects (280; 281; 282; 283; 32). AntihistaminesAntihistamines: According to secondary sources, ginger may interact with antihistamine agents.Anti-inflammatory agentsAnti-inflammatory agents: Ginger suppressed prostaglandin synthesis through the inhibition of cyclooxygenase-1 and cyclooxygenase-2, and suppressed leukotriene biosynthesis by inhibiting 5-lipoxygenase (284; 267). Therefore, ginger may have additive effects when taken with anti-inflammatory agents. According to animal research, Trikatu, an Ayurvedic formulation of a 1:1:1 ratio of dried fruits of Piper nigrum and Piper longum and dried rhizomes of Zingiber officinale, may decrease the bioavailability of diclofenac sodium (285). According to animal research, ginger may also lower body temperature (286). AntilipemicsAntilipemics: Oral ingestion of ginger extract has been shown to have hypocholesterolemic, hypolipidemic, and antiatherosclerotic effects in cholesterol-fed rabbits (141) and in rats (145). Similarly in human research, ginger powder increased high-density lipoprotein (HDL) cholesterol and reduced triglyceride, total cholesterol, and low-density lipoprotein (LDL) cholesterol vs. placebo (146). Inhibition of LDL oxidation and attenuated development of atherosclerosis has also been observed in apolipoprotein E-deficient mice (143). AntimalarialsAntimalarials: In humans, ginger-partitioned moxibustion demonstrated a positive rate of treatment effect (92%) in malaria patients (287). Antineoplastic agentsAntineoplastic agents: According to secondary sources, ginger may induce gastrointestinal bleeding when used with chemotherapy; however, the exact effects are unclear. Use of ginger with chemotherapy has been reported (288; 289); however, any interactions are unclear. In vitro, ginger and some of its constituents may have anticancer activity (290; 291; 292; 293; 44; 294; 295; 296; 297; 298; 299; 300; 301; 302; 162; 303; 304; 305; 306; 307; 308; 309; 310; 311; 312; 313; 314; 315; 316; 317; 65). The constituents isolated from ginger species, including curcumin, 6-gingerol, and labdane-type diterpene compounds, were found to have positive effects on cell proliferation and the induction of apoptosis in cultured human T lymphoma Jurkat cells (291). Ginger in food may interfere with cell-signaling pathways (290). Antiobesity drugsAntiobesity drugs: In animal research, oral administration of zingerone reduced body weight and adipose tissue weight in ovariectomized rats (318; 319). Ginger has been suggested as a possible weight loss aid (320; 321), although further evidence is needed to confirm these preliminary findings. AntiprotozoalsAntiprotozoals: In vitro, ginger extracts demonstrated a reduction in worm numbers (322; 323; 324). Antitussive agentsAntitussive agents: Constituents in ginger have exhibited antitussive effects (325). Antiviral agentsAntiviral agents: In vitro, ginger exerted antiviral activity via inhibition of hepatitis C virus protease and human cytomegalovirus protease (326). BenzodiazepinesBenzodiazepines: In animal research, a mixture of ginger and Ginkgo biloba extracts demonstrated anxiolytic effects in rats (156; 157; 158; 159). In theory, ginger may increase the amount of drowsiness caused by some drugs. Cardiac glycosidesCardiac glycosides: According to secondary sources, ginger may interact with cardiac glycoside agents.Cardiovascular drugsCardiovascular drugs: Ginger may interfere with medications that change the contraction of the heart, including beta-blockers and digoxin. Arrhythmias are theoretically possible at high doses, according to in vitro and in vivo research showing that components of ginger activate Ca2+-ATPase and have dose-dependent positive inotropic effects (142). According to animal research, ginger juice may increase the acute toxicity of quinidine (327). Anecdotally, some experts have reported hemodynamic effects of large doses, including hypertension or hypotension, although scientific data are lacking in this area. In vitro research indicates that gingerols and the related shogaols exhibit cardiodepressant activity at low doses and cardiotonic properties at higher doses (144). In human research, the coadministration of acupuncture and ginger-partitioned moxibustion demonstrated a higher rate of therapeutic efficacy for cardiac arrhythmias and a lower rate of arrhythmia recurrence and complications compared to conventional Western medications, such as aspirin, metoprolol, or propafenone (328). CNS depressantsCNS depressants: In animal research, a mixture of ginger and Ginkgo biloba extracts demonstrated anxiolytic effects in rats (156; 157; 158; 159). In theory, since large doses of ginger have been reported to depress the central nervous system (CNS), it may cause additive sedation when used with CNS-depressant drugs. CNS stimulantsCNS stimulants: Inhalation of ginger essential oil reduced immobility in mice (329). COX inhibitorsCOX inhibitors: According to a review, ginger has been shown to share pharmacological properties with nonsteroidal anti-inflammatory drugs (NSAIDs) because it suppresses prostaglandin synthesis through the inhibition of cyclooxygenase-1 and cyclooxygenase-2 (284). CyclosporineCyclosporine: According to animal research, ginger may decrease the oral bioavailability of cyclosporine (182). Cytochrome P450-modifying agentsCytochrome P450-modifying agents: The Chinese herbal medicine sho-saiko-to, which contains ginger and six other herbs (bupleurum, pinellia tuber, scutellaria root, jujube fruit, ginseng, and licorice root), has been associated in healthy humans with reduced activity of cytochrome P450 1A2, P450 3A, and xanthine oxidase (in 26 healthy subjects) (153). According to secondary sources, ginger may interact with such agents (330); however, the contribution of ginger to this effect is unclear. In addition, according to secondary sources, ginger may interact with cytochrome P450 2C9, 1A2, 2D6, and 3A4(4,5,7) inhibitors. Dental agentsDental agents: In humans, a combination herbal toothpaste (Sudantha) containing Zingiber officinale Roscoe, Acacia chundra Willd., Adhatoda vasica Nees, Mimusops elengi L., Piper nigrum L., Pongamia pinnata L.Pierre, Quercus infectoria Olivier, Syzygium aromaticum L., and Terminalia chebula Retz. decreased anaerobic bacterial count, plaque index, and the percentage of bleeding sites on probing (331). Dermatologic agentsDermatologic agents: Dermatitis may occur in individuals with sensitive skin when applied topically. Allergic contact dermatitis to ginger has been reported (189). Incidences of hives (149), rash (150), bruising and flushing (150), and other nonspecific skin conditions (151) have also been observed. EstrogensEstrogens: Ginger may exert high estrogenic potency, according to in vitro evidence (160). Gastrointestinal agentsGastrointestinal agents: According to secondary sources, the ginger rhizome (underground stem) may increase stomach acid production. Therefore, it may interfere with antacids, sucralfate (Carafate?), H2 antagonists, or proton pump inhibitors. In contrast, other in vitro and animal research has revealed gastroprotective properties (263; 264). Also, 6-shogaol has inhibited intestinal motility in intravenous preparations and facilitated gastrointestinal motility in oral preparations. Ginger extract, zingiberene, and 6-gingerol have been observed to afford cytoprotection against chemically induced ulceration in rats (263; 264), and ginger extract has been reported to inhibit the growth of Helicobacter pylori in vitro (56). However, clinical research indicated a significant increase in the exfoliation of gastric surface epithelial cells following the consumption of 6g or more of ginger (265). In human research, ginger monotherapy and combination therapy (Tongyan spray) have demonstrated effects on lower esophageal sphincter function (200), swallowing (266), gastric emptying (199), and stomach hormone levels (261). HypertensivesHypertensives: Anecdotally, some experts have reported hemodynamic effects of large doses, including hypertension or hypotension, although scientific data are lacking in this area. Theoretically, concurrent use may have additive effects.HypoglycemicsHypoglycemics: Theoretically, due to its purported hypoglycemic effects, ginger may lower blood glucose levels when taken concomitantly with hypoglycemic or antihyperglycemic herbs or supplements (134). HypotensivesHypotensives: In animal research, an aqueous extract of ginger induced a dose-dependent fall in arterial blood pressure (332). ImmunosuppressantsImmunosuppressants: In vitro evidence indicates that ginger may have immunomodulatory effects (154; 155). Impotence agentsImpotence agents: In vitro, Zingiber officinalis may exert short-lived and dose-dependent rabbit corpus cavernosum relaxations (333). MetronidazoleMetronidazole: In animal research, ginger may increase the absorption and plasma half-life, and significantly decrease the elimination rate constant and clearance, of metronidazole (270).Neurologic agentsNeurologic agents: In human research, sleepiness (147), minor sedation (3), headache (194), and dizziness (149) have been reported following ginger supplementation. NifedipineNifedipine: In human research, antiplatelet aggregation was increased when nifedipine and ginger were used. Nifedipine and ginger had a synergistic effect on the inhibition of platelet aggregation (181). Nonsteroidal anti-inflammatory agents (NSAIDs)Nonsteroidal anti-inflammatory agents (NSAIDs)
: According to a review, ginger has been shown to share pharmacological properties with nonsteroidal anti-inflammatory drugs (NSAIDs) because it suppresses prostaglandin synthesis through the inhibition of cyclooxygenase-1 and cyclooxygenase-2 (284). P-glycoprotein-regulated agentsP-glycoprotein-regulated agents: In vitro, 6-gingerol has been reported to have inhibitory effects on p-glycoprotein (334). Sedative agentsSedative agents: In animal research, a mixture of ginger and Ginkgo biloba extracts demonstrated anxiolytic effects in rats (156; 157; 158; 159). In theory, ginger may increase the amount of drowsiness caused by some agents. StimulantsStimulants: Inhalation of ginger essential oil reduced immobility in mice (329). VasodilatorsVasodilators: In animal research, mild vasodilator effects were observed following supplementation with ginger aqueous extract (332). Ginger/Herb/Supplement Interactions:
AnalgesicsAnalgesics: In animal and human research, ginger monotherapy and combination therapy have demonstrated analgesic effects (137; 260; 149; 1; 215; 261; 262; 217). AntacidsAntacids: According to secondary sources, the ginger rhizome (underground stem) may increase stomach acid production. Therefore, it may interfere with antacids, sucralfate (Carafate?), H2 antagonists, or proton pump inhibitors. In contrast, other in vitro and animal research has revealed gastroprotective properties (263; 264). Also, 6-shogaol has inhibited intestinal motility in intravenous preparations and facilitated gastrointestinal motility in oral preparations. Ginger extract, zingiberene, and 6-gingerol have been observed to afford cytoprotection against chemically induced ulceration in rats (263; 264), and ginger extract has been reported to inhibit the growth of Helicobacter pylori in vitro (56). However, clinical research has indicated a significant increase in the exfoliation of gastric surface epithelial cells following the consumption of 6g or more of ginger (265). In human research, ginger monotherapy and combination therapy (Tongyan spray) have demonstrated effects on lower esophageal sphincter function (200), swallowing (266), gastric emptying (199), and stomach hormone levels (261). Antiarrhythmic agentsAntiarrhythmic agents: Arrhythmias are theoretically possible at high doses, according to in vitro and in vivo studies showing that components of ginger activate Ca2+-ATPase and have dose-dependent positive inotropic effects (142). In an equivalence study comparing ginger and vitamin B6 for nausea, arrhythmia occurred in both groups but was minor and not significant (3). Antiarthritic herbs and supplementsAntiarthritic herbs and supplements: According to expert opinion, inhibition of prostaglandin and thromboxane formation by human platelets and the subsequent production of lipid peroxides have been proposed as possible mechanisms by which ginger might provide relief of rheumatoid arthritis symptoms (267). AntiasthmaticsAntiasthmatics: In humans, acupoint sticking coadministered with combination ginger medication cakes or ginger-partition moxibustion has been shown to improve symptoms of bronchial asthma and self-reported quality of life (268; 269). AntibacterialsAntibacterials: According to animal research, ginger may increase the absorption and plasma half-life, and significantly decrease the elimination rate constant and clearance, of metronidazole (270). In vitro, ginger and some of its constituents may have antibacterial activity (162; 163; 164; 165; 166; 167; 168; 169; 170; 171; 172; 173; 174; 175; 176; 177; 178; 179; 180). Anticoagulants and antiplateletsAnticoagulants and antiplatelets: In theory, inhibition of thromboxane synthetase and decreased platelet aggregation have been reported in clinical trials (271; 272; 185; 186). Concurrent use of ginger with agents that predispose patients to bleeding may enhance their effect and increase the risk of bleeding. One observational study found that frequent (more than four times weekly) dietary consumption of herbs was associated with an INR outside of optimal therapeutic range (274). According to a case report, a patient using chronic warfarin had an increase in the INR after initiating therapy with ginger (214). It is unclear to what extent ginger was responsible for this rise in the INR, although another case report indicated a possible anticoagulant interaction with concurrent use of ginger (247), and the results from one clinical trial suggest that ginger lacks effect on the pharmacokinetic and pharmacodynamic profile of warfarin and subsequently, on the clotting status of healthy individuals (275). Concurrent use of ginger has been associated with an increased risk of self-reported bleeding in patients taking warfarin (273). Antidepressants: selective serotonin reuptake inhibitors (SSRIs)Antidepressants: selective serotonin reuptake inhibitors (SSRIs): In vitro, ginger may antagonize serotonin receptors (161) and theoretically may interfere with herbs or supplements with SSRI effects. Antidiabetic agentsAntidiabetic agents: In animal research, treatment of streptozotocin (STZ)-induced type 1 diabetic rats with Zingiber officinale significantly increased insulin levels and decreased fasting glucose levels and also decreased serum cholesterol, serum triglyceride, and blood pressure (135; 136; 137; 138; 139; 140). Theoretically, due to its purported hypoglycemic effects, ginger may interfere with diabetes therapy, potentially requiring dosing adjustments (134). AntiemeticsAntiemetics: Ginger, administered as both monotherapy and combination therapy (KSS formula), has been shown to have antiemetic effects in clinical trials (209; 3; 4; 17; 276; 7; 19; 208; 210; 5; 8; 9; 11; 201; 12; 13; 150; 197; 277; 278; 14) and in animal research (279). Additive effects may occur when taken concomitantly with other antiemetics. Antifungal agentsAntifungal agents: In vitro, ginger and some of its constituents exerted antifungal effects (280; 281; 282; 283; 32). AntihistaminesAntihistamines: According to secondary sources, ginger may interact with antihistamine agents.Anti-inflammatory herbs and supplementsAnti-inflammatory herbs and supplements: According to a review, ginger suppressed prostaglandin synthesis through the inhibition of cyclooxygenase-1 and cyclooxygenase-2, as well as leukotriene biosynthesis by inhibiting 5-lipoxygenase (284; 267). In animal research, ginger may lower body temperature (286). AntilipemicsAntilipemics: Oral ingestion of ginger extract has been shown to have hypocholesterolemic, hypolipidemic, and antiatherosclerotic effects in cholesterol-fed rabbits (141) and in rats (145). Similarly in human research, ginger powder increased high-density lipoprotein (HDL) cholesterol and reduced triglyceride, total cholesterol, and LDL cholesterol vs. placebo (146). Inhibition of LDL oxidation and attenuated development of atherosclerosis has also been observed in apolipoprotein E-deficient mice (143). AntimalarialsAntimalarials: In humans, ginger-partitioned moxibustion demonstrated a positive rate of treatment effect (92%) in malaria patients (287). AntineoplasticsAntineoplastics: According to secondary sources, ginger may induce gastrointestinal bleeding when used with chemotherapy; however, the exact effects are unclear. Use of ginger with chemotherapy has been reported (288; 289); however, any interactions are unclear. In vitro, ginger and some of its constituents may show anticancer activity (290; 291; 292; 293; 44; 294; 295; 296; 297; 298; 299; 300; 301; 302; 162; 303; 304; 305; 306; 307; 308; 309; 310; 311; 312; 313; 314; 315; 316; 317). The constituents isolated from ginger species, including curcumin, 6-gingerol, and labdane-type diterpene compounds, were found to have positive effects on cell proliferation and the induction of apoptosis in cultured human T lymphoma Jurkat cells (291). Ginger in food may interfere with cell-signaling pathways (290). Antiobesity herbs and supplementsAntiobesity herbs and supplements: In animal research, oral administration of zingerone reduced body weight and adipose tissue weight in ovariectomized rats (318; 319). Ginger has been suggested as a possible weight loss aid (320; 321), although further evidence is needed to confirm these preliminary findings. AntiparasiticsAntiparasitics: In vitro, ginger extracts demonstrated a reduction in worm numbers, as well as antifungal activity (322; 323; 324). AntitussivesAntitussives: Constituents in ginger have exhibited antitussive effects (325). Antiviral agentsAntiviral agents: In vitro, ginger exerted antiviral activity via inhibition of hepatitis C virus protease and human cytomegalovirus protease (326). CalciumCalcium: Ginger or ginger extracts may stimulate calcium uptake in both skeletal and cardiac muscle. In vitro research on gingerol involving canine cardiac tissue and rabbit skeletal muscle demonstrated that gingerol activates the Ca2+-ATPase pump in a dose-dependent manner (359). In theory, ginger coupled with high serum levels of calcium may cause hyperexcitability of cardiac muscle. Cardiac glycosidesCardiac glycosides: According to secondary sources, ginger may interact with cardiac glycoside agents.Cardiovascular herbs and supplementsCardiovascular herbs and supplements: Ginger may also interfere with medications that change the contraction of the heart. Arrhythmias are theoretically possible at high doses, according to in vitro and in vivo research showing that components of ginger activate Ca2+-ATPase and have dose-dependent positive inotropic effects (142). In animal research, ginger juice may increase the acute toxicity of some cardiovascular agents (327). Anecdotally, some experts have reported hemodynamic effects of large doses, including hypertension or hypotension, although scientific data are lacking in this area. In vitro research indicates that gingerols and the related shogaols exhibit cardiodepressant activity at low doses and cardiotonic properties at higher doses (144). In human research, the coadministration of acupuncture and ginger-partitioned moxibustion demonstrated a higher rate of therapeutic efficacy for cardiac arrhythmias and a lower rate of arrhythmia recurrence and complications compared to conventional Western medications, such as aspirin, metoprolol, or propafenone (328). COX inhibitorsCOX inhibitors: According to a review, ginger has been shown to share pharmacological properties with nonsteroidal anti-inflammatory drugs (NSAIDs) because it suppresses prostaglandin synthesis through the inhibition of cyclooxygenase-1 and cyclooxygenase-2 (284). Cytochrome P450-modifying herbs and supplementsCytochrome P450-modifying herbs and supplements: The Chinese herbal medicine sho-saiko-to contains ginger and six other herbs (bupleurum, pinellia tuber, scutellaria root, jujube fruit, ginseng, and licorice root) and has been associated in healthy humans with reduced activity of cytochrome P450 1A2, P450 3A, and xanthine oxidase (in 26 healthy subjects) (153). The contribution of ginger alone to this effect is unclear. In addition, according to secondary sources, ginger may interact with cytochrome P450 2C9, 1A2, 2D6, and 3A4(4,5,7) inhibitors. Dental agentsDental agents: In humans, combination herbal toothpaste (Sudantha) containing Zingiber officinale Roscoe, Acacia chundra Willd., Adhatoda vasica Nees, Mimusops elengi L., Piper nigrum L., Pongamia pinnata L.Pierre, Quercus infectoria Olivier, Syzygium aromaticum L., and Terminalia chebula Retz. decreased anaerobic bacterial count, plaque index, and the percentage of bleeding sites on probing (331). GarlicGarlic: In theory, since ginger has been observed to inhibit thromboxane synthetase, the concurrent use of ginger with agents that predispose patients to bleeding, such as garlic or ginkgo, may enhance their effect and increase the risk of bleeding (271; 272; 185; 186). In animal research, a combination of garlic and ginger was found to be more effective in reducing blood glucose and serum lipids (360). Gastrointestinal herbs and supplementsGastrointestinal herbs and supplements: According to secondary sources, ginger rhizome (underground stem) may increase stomach acid production. In contrast, other in vitro and animal study has revealed gastroprotective properties (263; 264). Ginger extract, zingiberene, and 6-gingerol have been observed to afford cytoprotection against chemically induced ulceration in rats (263; 264), and ginger extract has been reported to inhibit the growth of Helicobacter pylori in vitro (56). However, clinical research indicated a significant increase in the exfoliation of gastric surface epithelial cells following the consumption of 6g or more of ginger (265). In human research, ginger monotherapy and combination therapy (Tongyan spray) have demonstrated effects on lower esophageal sphincter function (200), swallowing (266), gastric emptying (199), and stomach hormone levels (261). GinkgoGinkgo: In theory, since ginger has been observed to inhibit thromboxane synthetase, the concurrent use of ginger with agents that predispose patients to bleeding, such as garlic or ginkgo, may enhance their effect and increase the risk of bleeding (271; 272; 185; 186). Herbs or supplements used in hematology and blood disordersHerbs or supplements used in hematology and blood disorders: In theory, since ginger has been observed to inhibit thromboxane synthetase, concurrent use of ginger with agents that predispose patients to bleeding, such as garlic or ginkgo, may enhance their effect and increase the risk of bleeding (271; 272; 185; 186). According to a case report, a patient using chronic warfarin had an increase in the international normalized ratio (INR) after initiating therapy with ginger (214). It is not clear to what extent ginger was responsible for this rise in INR. HypertensivesHypertensives: Anecdotally, some experts report hemodynamic effects of large doses, including hypertension or hypotension, although scientific data are lacking in this area. Theoretically, concurrent use may have additive effects.HypoglycemicsHypoglycemics: Theoretically, due to its purported hypoglycemic effects, ginger may lower blood glucose levels when taken concomitantly with hypoglycemic or antihyperglycemic herbs or supplements (134). HypotensivesHypotensives: In animal research, an aqueous extract of ginger induced a dose-dependent fall in arterial blood pressure (332). ImmunostimulantsImmunostimulants: The authors of a systematic review concluded that in vitro evidence indicates that ginger has immunomodulatory effects and is an effective antimicrobial and antiviral agent (228). ImmunosuppressantsImmunosuppressants: The authors of one systematic review concluded that in vitro evidence indicates that ginger has immunomodulatory effects and is an effective antimicrobial and antiviral agent (228). Impotence herbs and supplementsImpotence herbs and supplements: In vitro, Z. officinalis may exert short-lived and dose-dependent rabbit corpus cavernosum relaxations (333). Neurologic agentsNeurologic agents: In human research, sleepiness (147), minor sedation (3), headache (194), and dizziness (149) have been reported. Perillyl alcohol-containing agentsPerillyl alcohol-containing agents: According to secondary sources, ginger may interact with perillyl alcohol-containing agents.P-glycoprotein-regulated agentsP-glycoprotein-regulated agents: In vitro, 6-gingerol has been reported to have inhibitory effects on p-glycoprotein (334). PhytoestrogensPhytoestrogens: Ginger may exert high estrogenic potency, according to in vitro evidence (160). Sedative herbs and supplementsSedative herbs and supplements: In animal research, a mixture of ginger and Ginkgo biloba extracts demonstrated anxiolytic effects in rats (156; 157; 158; 159). In theory, ginger may increase the amount of drowsiness caused by some herbs or supplements. StimulantsStimulants: Inhalation of ginger essential oil has been shown to reduce immobility in mice (329). VasodilatorsVasodilators: In animal research, mild vasodilator effects were observed (332). Ginger/Food Interactions:
GarlicGarlic: In theory, since ginger has been observed to inhibit thromboxane synthetase, the concurrent use of ginger with agents that predispose patients to bleeding, such as garlic or ginkgo, may enhance their effect and increase the risk of bleeding (271; 272; 185; 186). In animal research, a combination of garlic and ginger was found to be more effective in reducing blood glucose and serum lipids (360). Ginger/Lab Interactions:
Blood pressureBlood pressure: An aqueous extract of ginger induced a dose-dependent (3-10mg/kg) fall in the arterial blood pressure (BP) of anesthetized rats, which was partially blocked by atropine (1mg/kg) (332). Blood glucoseBlood glucose: Theoretically, due to its purported hypoglycemic effects, ginger may lower blood glucose levels when taken concomitantly with hypoglycemic or antihyperglycemic herbs or supplements (134). Coagulation panelCoagulation panel: There is a European case report of a 75 year-old woman taking chronic warfarin whose international normalized ratio (INR) rose after initiating therapy with ginger and was complicated by epistaxis (214). Her INR normalized after discontinuation of ginger and treatment with vitamin K. It is unclear to what extent ginger was responsible for this rise in the INR. In one clinical trial, ginger did not affect the pharmacokinetics or pharmacodynamics of warfarin in healthy subjects (361). However, studies in patients taking anticoagulants are needed to assess the clinical significance of these interactions. LipidsLipids: Oral ingestion of ginger extract has been shown to have hypocholesterolemic, hypolipidemic, and antiatherosclerotic effects in cholesterol-fed rabbits (141) and in rats (145). Similarly in human research, ginger powder increased high-density lipoprotein (HDL) cholesterol and reduced triglyceride, total cholesterol, and (low-density lipoprotein) LDL cholesterol vs. placebo (146). Inhibition of LDL oxidation and attenuated development of atherosclerosis have also been observed in apolipoprotein E-deficient mice (143). Liver enzymesLiver enzymes: The ethanol extract of the rhizome of Zingiber officinale attenuated, in a dose-dependent manner, CCl(4)- and acetaminophen-induced increases in the activities of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, lactate dehydrogenase, and sorbitol dehydrogenases in the blood serum (362).