Thiamin

Thiamine/Drug Interactions:

  • AlcoholAlcohol: Heavy use of alcohol may lead to thiamine deficiency and Wernicke's encephalopathy. Thiamine administration is required. Reasons for thiamine deficiency associated with alcoholism include inadequate intake, decreased conversion of thiamine to its active coenzyme (thiamine pyrophosphate), and reduced absorption, storage, and transport (203; 204; 205; 206). Scientists have suggested that genetic predisposition to thiamine deficiency may contribute to alcoholism-associated dysfunction of the brain and other organ systems (207; 208; 209; 210; 211).
  • Alzheimer's agentsAlzheimer's agents: Because thiamine deficiency can result in a form of dementia (Wernicke-Korsakoff syndrome), its relationship to Alzheimer's disease and other forms of dementia has been investigated (212). Whether thiamine supplementation is of benefit in Alzheimer's disease remains controversial (212). In dementia of the Alzheimer's-type brain, alpha-ketoglutarate dehydrogenase complex activity, dependent on thiamine pyrophosphate, is reduced (213).
  • AnalgesicsAnalgesics: In animal research, thiamine has been shown to have analgesic effects (214).
  • AntacidsAntacids: According to secondary sources, antacids may lower thiamine levels in the body by decreasing absorption and increasing excretion or metabolism.
  • AntibioticsAntibiotics: According to secondary sources, antibiotics destroy gastrointestinal flora (normal bacteria in the gut), which manufacture some B vitamins. In theory, this may decrease the amount of thiamine available to humans, although the majority of thiamine is obtained through the diet (not via bacterial production).
  • AntihypertensivesAntihypertensives: In an elderly population with subclinical thiamine deficiency, thiamine supplementation resulted in decreased systolic blood pressure (165).
  • Antineoplastic agentsAntineoplastic agents: According to secondary sources, people receiving fluorouracil-containing chemotherapy regimens may be at risk for developing symptoms and signs of thiamine deficiency. According to review data, the antineoplastic activities of thiamine may be due to its antioxidant effects (215). However, some authors have suggested that thiamine is oversupplied in cancer patients because it is considered harmless by many (169). They have suggested limiting administration of thiamine in these patients (169), considering the potential for procancer effects from thiamine (168; 169; 170).
  • AntiretroviralsAntiretrovirals: Thiamine has been investigated as a therapeutic strategy for lactic acidosis associated with antiretroviral therapy (216).
  • Athletic performance enhancersAthletic performance enhancers: In human research, thiamine has been shown to decrease serum lactate levels and heart rate and increase VO2max (166). According to review data, active individuals who reduce intake of food may be at greater risk of vitamin deficiency, including thiamine deficiency (95). Thiamine intakes and blood levels in Tour de France athletes were very high due to intake of enriched sports drinks and intramuscular injections (217).
  • BarbituratesBarbiturates: According to secondary sources, barbiturates may lower thiamine levels in the body by decreasing absorption and increasing excretion or metabolism.
  • Cardiovascular agentsCardiovascular agents: In human research, thiamine supplementation had benefits for patients with heart failure (218; 219; 220; 221). Thiamine deficiency has been associated with ventricular dilation and dysfunction (222) and myocardial failure (223; 224; 225; 226; 219). In human research, thiamine pyrophosphate (TPP) has been shown to decrease heart rate (166).
  • DextroseDextrose: The combination of dextrose, flumazenil, naloxone and thiamine, or a "coma cocktail," has been used in patients in a coma (227; 228).
  • DichloroacetateDichloroacetate: According to a review, dichloroacetate may cause a reversible peripheral neuropathy that may be related to thiamine deficiency and may be improved with thiamine supplementation (229).
  • DiureticsDiuretics: Thiamine supplementation is often suggested in persons using diuretics, due to increased urinary loss (230; 231; 232; 233). Loop diuretics, particularly furosemide (Lasix?), have been associated with decreased thiamine levels in the body from increasing urinary excretion (and possibly from decreasing absorption and increasing metabolism) (234). Examples of other loop diuretics include bumetanide (Bumex?), ethacrynic acid (Edecrin?), and torsemide (Demadex?). Theoretically, this effect may also occur with other types of diuretics, including thiazide diuretics, such as chlorothiazide (Diuril?), chlorthalidone (Hygroton?, Thalitone?), hydrochlorothiazide (HCTZ, Esidrix?, HydroDIURIL?, Oretic?, Microzide?), indapamide (Lozol?), and metolazone (Zaroxolyn?), and potassium-sparing diuretics, such as amiloride (Midamor?), spironolactone (Aldactone?), and triamterene (Dyrenium?). Effects may be most pronounced with larger doses taken over extended periods of time.
  • FlumazenilFlumazenil: The combination of dextrose, flumazenil, naloxone and thiamine, or a "coma cocktail," has been used in patients in a coma (227; 228).
  • Heart rate-regulating agentsHeart rate-regulating agents: In human research, thiamine pyrophosphate (TPP) has been shown to decrease heart rate (166).
  • HypoglycemicsHypoglycemics: Thiamine has been the topic of reviews as a preventive agent for diabetic complications, including neuropathies, retinopathy, microangiopathies, and nephropathies (235; 236; 237; 238; 239; 240; 241). Thiamine may play a role in the prevention of advanced glycation end products (242). According to review data, other diabetic complications that may benefit from thiamine supplementation include increased diuresis, glucosuria, and dyslipidemia (243). Although thiamine supplementation does not appear to affect blood sugar levels in humans (167), impaired glucose tolerance may be associated with thiamine deficiency.
  • IfosfamideIfosfamide: The role of thiamine in preventing ifosfamide-induced encephalopathy has been discussed (244). Further details are lacking at this time.
  • ImmunostimulantsImmunostimulants: According to reviews, thiamine is involved in the immune response, including humoral antibody formation (189; 190).
  • ImmunosuppressantsImmunosuppressants: According to reviews, thiamine is involved in the immune response, including humoral antibody formation (189; 190).
  • MetforminMetformin: Theoretically, metformin may reduce thiamine activity.
  • NaloxoneNaloxone: The combination of dextrose, flumazenil, naloxone and thiamine, or a "coma cocktail," has been used in patients in a coma (227; 228).
  • Neurologic agentsNeurologic agents: Thiamine deficiency symptoms include neurologic manifestations (245). In dementia of the Alzheimer's-type brain, alpha-ketoglutarate dehydrogenase complex activity, dependent on thiamine pyrophosphate, is reduced (213). Information from a review suggests that activities of the thiamine phosphate dephosphorylating enzymes (thiamine diphosphatase (TDPase) and thiamine monophosphatase (TMPase)) and thiamine diphosphate-dependent enzymes (pyruvate dehydrogenase complex, alpha-ketoglutarate dehydrogenase, and transketolase) are reduced in autopsied brain tissue (246). In animal research, thiamine treatment prevented memory deficit associated with thiamine deficiency feeding (247).
  • Neuromuscular blocking agentsNeuromuscular blocking agents: According to secondary sources, the effects of neuromuscular blocking agents (NMBAs) may be enhanced with concomitant use of thiamine.
  • Oral contraceptivesOral contraceptives: According to review data, the use of oral contraceptives may increase the risk of thiamine deficiency (248).
  • PhenytoinPhenytoin: According to secondary sources, reduced levels of thiamine in blood and cerebrospinal fluid have been reported in individuals taking phenytoin (Dilantin?) for extended periods of time.
  • Thyroid hormoneThyroid hormone: According to a review, thiamine uptake is reduced by thyroid hormone (249).
  • TobaccoTobacco: According to secondary sources, tobacco use decreases thiamine absorption and may lead to decreased levels in the body.
  • VasodilatorsVasodilators: Thiamine has been shown to improve vasodilation in patients with high blood sugar levels or diabetes (167).
  • Weight loss agentsWeight loss agents: In an elderly population with subclinical thiamine deficiency, thiamine supplementation resulted in decreased weight (165).

    • Thiamine/Herb/Supplement Interactions:

  • Alzheimer's agentsAlzheimer's agents: Because thiamine deficiency can result in a form of dementia (Wernicke-Korsakoff syndrome), its relationship to Alzheimer's disease and other forms of dementia has been investigated (212). Whether thiamine supplementation is of benefit in Alzheimer's disease remains controversial (212). In dementia of the Alzheimer's-type brain, alpha-ketoglutarate dehydrogenase complex activity, dependent on thiamine pyrophosphate, is reduced (213).
  • AnalgesicsAnalgesics: In animal research, thiamine has been shown to have analgesic effects (214).
  • AntacidsAntacids: According to secondary sources, antacids may lower thiamine levels in the body by decreasing absorption and increasing excretion or metabolism.
  • AntibacterialsAntibacterials: According to secondary sources, antibiotics destroy gastrointestinal flora (normal bacteria in the gut), which manufacture some B vitamins. Theoretically, this may decrease the amount of thiamine available to humans, although the majority of thiamine is obtained through the diet (not via bacterial production).
  • AntineoplasticsAntineoplastics: According to review data, the antineoplastic activities of thiamine may be due to its antioxidant effects (215). However, some authors suggest that thiamine is oversupplied in cancer patients because it is considered harmless by many (169). They suggest limiting administration of thiamine in these patients (169), considering the potential for procancer effects from thiamine (168; 169; 170).
  • Athletic performance enhancersAthletic performance enhancers: In human research, thiamine has been shown to decrease serum lactate levels and heart rate and increase VO2max (166). According to review data, active individuals who reduce intake of food may be at greater risk of vitamin deficiency, including thiamine deficiency (95). Thiamine intakes and blood levels in Tour de France athletes were very high due to intake of enriched sports drinks and intramuscular injections (217).
  • BenfotiamineBenfotiamine: Benfotiamine is a synthetic S-acyl derivative of thiamine that increases blood levels of thiamine (250).
  • Betel nutsBetel nuts: In human research, consumption of betel nuts (Areca catechu L.) reduced thiamine activity due to chemical inactivation, and may lead to symptoms and signs of thiamine deficiency (251).
  • Cardiovascular agentsCardiovascular agents: In human research, thiamine supplementation had benefits for patients with heart failure (218; 219; 220; 221). Thiamine deficiency is associated with ventricular dilation and dysfunction (222) and myocardial failure (223; 224; 225; 226; 219). In human research, thiamine pyrophosphate (TPP) has been shown to decrease heart rate (166).
  • ContraceptivesContraceptives: According to review data, use of oral contraceptives may increase the risk of thiamine deficiency (248).
  • DiureticsDiuretics: Thiamine supplementation is often suggested in persons using diuretics, due to increased urinary loss (230; 231; 232; 233).
  • Heart rate-regulating agentsHeart rate-regulating agents: In human research, thiamine pyrophosphate (TPP) has been shown to decrease heart rate (166).
  • HorsetailHorsetail: The potential antithiamine effects of horsetail (Equisetum arvense L.) have been discussed in a review (252). According to secondary sources, horsetail contains a thiaminase-like compound that may destroy thiamine in the stomach and theoretically may cause symptomatic thiamine deficiency. Horsetail products are available without this property, and, for example, the Canadian government requires that horsetail products be certified free of thiaminase activity.
  • HypoglycemicsHypoglycemics: Thiamine has been the topic of reviews as a preventive agent for diabetic complications, including neuropathies, retinopathy, microangiopathies, and nephropathies (235; 236; 237; 238; 239; 240). Thiamine may play a role in the prevention of advanced glycation end products (242). According to review data, other diabetic complications that may benefit from thiamine supplementation include increased diuresis, glucosuria, and dyslipidemia (243). Although thiamine supplementation does not appear to affect blood sugar levels in humans (167), impaired glucose tolerance may be associated with thiamine deficiency.
  • HypotensivesHypotensives: In an elderly population with subclinical thiamine deficiency, thiamine supplementation resulted in decreased systolic blood pressure (165).
  • ImmunomodulatorsImmunomodulators: According to reviews, thiamine is involved in the immune response, including humoral antibody formation (189; 190).
  • Neurologic agentsNeurologic agents: Thiamine deficiency symptoms include neurologic manifestations (245). In dementia of the Alzheimer's-type brain, alpha-ketoglutarate dehydrogenase complex activity, dependent on thiamine pyrophosphate, is reduced (213). Information from a review suggests that activities of the thiamine phosphate dephosphorylating enzymes (thiamine diphosphatase (TDPase) and thiamine monophosphatase (TMPase)) and thiamine diphosphate-dependent enzymes (pyruvate dehydrogenase complex, alpha-ketoglutarate dehydrogenase, and transketolase) are reduced in autopsied brain tissue (246). In animal research, thiamine treatment prevented memory deficit associated with thiamine deficiency feeding (247).
  • Neuromuscular blocking agentsNeuromuscular blocking agents: According to secondary sources, the effects of neuromuscular blocking agents (NMBAs) may be enhanced with concomitant use of thiamine.
  • PolyphenolsPolyphenols: According to a review of in vitro and animal studies, polyphenols may effect intestinal and placental transport of thiamine (253). According to secondary sources, chronic intake of polyphenols such as tannins in coffee and tea may convert thiamine to an unabsorbable and inactive form and theoretically can worsen or cause thiamine deficiency. However, this interaction appears to lack clinical relevance in industrialized countries, where most individuals consume adequate dietary thiamine and ascorbic acid (which prevents this interaction). This interaction has been described in Asian populations that chew fermented tea leaves.
  • SedativesSedatives: According to secondary sources, barbiturates may lower thiamine levels in the body by decreasing absorption and increasing excretion or metabolism.
  • Thyroid agentsThyroid agents: According to a review, thiamine uptake is reduced by thyroid hormone (249).
  • TobaccoTobacco: According to secondary sources, tobacco use decreases thiamine absorption and may lead to decreased levels in the body.
  • VasodilatorsVasodilators: Thiamine has been shown to improve vasodilation in patients with high blood sugar levels or diabetes (167).
  • VitaminsVitamins: The interaction of thiamine with other B vitamins has been discussed in a review (254). The authors suggested that the interactions of the B-complex vitamins are essential for metabolic and catabolic reactions in the body, and that vitamin C and the fat-soluble vitamins may also be involved in the interactions.
  • Weight loss agentsWeight loss agents: In an elderly population with subclinical thiamine deficiency, thiamine supplementation resulted in decreased weight (165).

    • Thiamine/Food Interactions:

  • Betel nutsBetel nuts: In human research, consumption of betel nuts (Areca catechu L.) reduced thiamine activity due to chemical inactivation, and it may lead to symptoms and signs of thiamine deficiency (251).
  • Carbonated beveragesCarbonated beverages: According to secondary sources, carbonated beverages may decrease the effects of thiamine in the body.
  • Citrate-containing foods or beveragesCitrate-containing foods or beverages: According to secondary sources, foods or beverages with citrates may decrease the effects of thiamine in the body.
  • Food preservativesFood preservatives: The effects of sulfite on thiamine have been reported (256). Further details are unknown at this time.
  • Foods containing antithiamine factorsFoods containing antithiamine factors: Beriberi caused by antithiamine factors in food and its prevention have been discussed (255). Further details are lacking at this time, although it has been suggested in secondary sources that some foods (e.g., coffee) contain enzymes that may break down thiamine.
  • Raw seafoodRaw seafood: Raw freshwater fish and shellfish contain thiaminase enzymes that destroy thiamine. Cooking destroys these enzymes, and therefore consumption of cooked seafood lacks an effect on thiamine levels.
  • SucroseSucrose: Sucrose was theoretically thought to deplete the body of nutrients such as thiamine, however, such evidence is lacking (257).
  • Tannin-containing beverages (coffee, tea)Tannin-containing beverages (coffee, tea): According to secondary sources, chronic intake of polyphenols such as tannins in coffee and tea may convert thiamine to an unabsorbable and inactive form, and theoretically may worsen or cause thiamine deficiency. However, this interaction appears to lack clinical relevance in industrialized countries, where most individuals consume adequate dietary thiamine and ascorbic acid (which prevents this interaction). This interaction has been described in Asian populations that chew fermented tea leaves.

    • Thiamine/Lab Interactions:

  • Advanced glycation end productsAdvanced glycation end products: Thiamine may play a role in the prevention of advanced glycation end products (242). In hemodialysis patients, high-dose thiamine lacked effect on advanced glycation end products (258).
  • Blood glucoseBlood glucose: Although thiamine supplementation lacks an effect on blood sugar levels in humans (167), impaired glucose tolerance may be associated with thiamine deficiency.
  • Blood pressureBlood pressure: In an elderly population with subclinical thiamine deficiency, thiamine supplementation resulted in decreased systolic blood pressure (165).
  • Body weightBody weight: In an elderly population with subclinical thiamine deficiency, thiamine supplementation resulted in decreased weight (165).
  • Heart rateHeart rate: In human research, thiamine pyrophosphate (TPP) has been shown to decrease heart rate (166).
  • Immune panelImmune panel: According to reviews, thiamine is involved in the immune response, including humoral antibody formation (189; 190).
  • Oxidative stress markersOxidative stress markers: In hemodialysis patients, high-dose thiamine lacked effect on oxidative stress markers (258).
  • PyruvatePyruvate: In burn patients, thiamine supplementation has been shown to reduce lactate levels (259).
  • Urinary albumin excretion (UAE)Urinary albumin excretion (UAE): In a pilot study of type 2 diabetic patients with microalbuminuria, high doses of thiamine for three months resulted in decreased UAE (260).
  • VO2maxVO2max: In human research, thiamine has been shown to increase VO2max (166).