thiamine (Rx, OTC)

Brand and Other Names:vitamin B1
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Dosing & Uses

AdultPediatric

Dosage Forms & Strengths

tablet

  • 50mg
  • 100mg
  • 250mg

capsule

  • 50mg

injectable solution

  • 100mg/mL

RDA

Males: 1.2 mg/day

Females: 1.1 mg/day

Pregnancy/Lactation: 1.4 mg/day

Beriberi

IM: 5-30 mg three times daily (if critically ill); then 5-30 mg three times daily for 1 month

Duration dependent on persistence of symptoms

Wernicke Encephalopathy

100 mg IV; then 50-100 mg/day IM or IV until consuming regular balanced diet

Thiamin Deficiency

1 tablet or capsule/day

Need for thiamin increases when carbohydrate content of diet is high

Dosage Forms & Strengths

tablet

  • 50mg
  • 100mg
  • 250mg

capsule

  • 50mg

injectable solution

  • 100mg/mL

RDA

0-6 months: 0.2 mg/day

6-12 months: 0.3 mg/day

1-3 years old: 0.5 mg/day

3-8 years old: 0.6 mg/day

8-13 years old: 0.9 mg/day

13-18 years old: 1.2 mg/day (male), 1 mg/day (female)

Deficiency

10-50 mg/day PO in divided doses

Beriberi

10-25 mg IV/IM qDay (if crtically ill) or 10-50 mg/dose PO qDay for at least 2 weeks, THEN

5-10 mg/day PO for 1 month

Duration dependent on persistence of symptoms

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Interactions

Interaction Checker

and thiamine

No Results

     activity indicator 
    No Interactions Found
    Interactions Found

    Contraindicated

      Serious - Use Alternative

        Significant - Monitor Closely

          Minor

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             activity indicator 

            Contraindicated (0)

              Serious - Use Alternative (0)

                Monitor Closely (8)

                • azithromycin

                  azithromycin will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Use Caution/Monitor.

                • clarithromycin

                  clarithromycin will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Use Caution/Monitor.

                • erythromycin base

                  erythromycin base will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Use Caution/Monitor.

                • erythromycin ethylsuccinate

                  erythromycin ethylsuccinate will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Use Caution/Monitor.

                • erythromycin lactobionate

                  erythromycin lactobionate will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Use Caution/Monitor.

                • erythromycin stearate

                  erythromycin stearate will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Use Caution/Monitor.

                • omadacycline

                  thiamine will decrease the level or effect of omadacycline by inhibition of GI absorption. Applies only to oral form of both agents. Modify Therapy/Monitor Closely. Multivalent cation-containing products may impair absorption of tetracyclines, which may decrease its efficacy. Separate dosing of tetracyclines from these products.

                • roxithromycin

                  roxithromycin will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Use Caution/Monitor.

                Minor (59)

                • amikacin

                  amikacin will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • atracurium

                  thiamine increases effects of atracurium by unspecified interaction mechanism. Minor/Significance Unknown.

                • aztreonam

                  aztreonam will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • bumetanide

                  bumetanide decreases levels of thiamine by increasing renal clearance. Minor/Significance Unknown.

                • caffeine

                  caffeine decreases levels of thiamine by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown. Coffee, tea are high in anti-thiamine factors.

                • cefadroxil

                  cefadroxil will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • cefamandole

                  cefamandole will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • cefpirome

                  cefpirome will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • ceftibuten

                  ceftibuten will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • cephalexin

                  cephalexin will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • chlorhexidine oral

                  chlorhexidine oral will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • ciprofloxacin

                  ciprofloxacin will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • cisatracurium

                  thiamine increases effects of cisatracurium by unspecified interaction mechanism. Minor/Significance Unknown.

                • clindamycin

                  clindamycin will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • dapsone

                  dapsone will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • demeclocycline

                  demeclocycline will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • doxycycline

                  doxycycline will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • ertapenem

                  ertapenem will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • ethacrynic acid

                  ethacrynic acid decreases levels of thiamine by increasing renal clearance. Minor/Significance Unknown.

                • ethanol

                  ethanol decreases levels of thiamine by inhibition of GI absorption. Applies only to oral form of both agents. Minor/Significance Unknown. Thiamine supplementation recommended in alcoholism.

                • fleroxacin

                  fleroxacin will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • fosfomycin

                  fosfomycin will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • furosemide

                  furosemide decreases levels of thiamine by increasing renal clearance. Minor/Significance Unknown.

                • gemifloxacin

                  gemifloxacin will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • gentamicin

                  gentamicin will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • levofloxacin

                  levofloxacin will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • linezolid

                  linezolid will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • meropenem

                  meropenem will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • meropenem/vaborbactam

                  meropenem/vaborbactam will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • metronidazole

                  metronidazole will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • minocycline

                  minocycline will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • moxifloxacin

                  moxifloxacin will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • nafcillin

                  nafcillin will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • neomycin PO

                  neomycin PO will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • nitrofurantoin

                  nitrofurantoin will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • ofloxacin

                  ofloxacin will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • onabotulinumtoxinA

                  thiamine increases effects of onabotulinumtoxinA by unspecified interaction mechanism. Minor/Significance Unknown.

                • oxytetracycline

                  oxytetracycline will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • pancuronium

                  thiamine increases effects of pancuronium by unspecified interaction mechanism. Minor/Significance Unknown.

                • paromomycin

                  paromomycin will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • pivmecillinam

                  pivmecillinam will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • quinupristin/dalfopristin

                  quinupristin/dalfopristin will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • rapacuronium

                  thiamine increases effects of rapacuronium by unspecified interaction mechanism. Minor/Significance Unknown.

                • rocuronium

                  thiamine increases effects of rocuronium by unspecified interaction mechanism. Minor/Significance Unknown.

                • streptomycin

                  streptomycin will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • succinylcholine

                  thiamine increases effects of succinylcholine by unspecified interaction mechanism. Minor/Significance Unknown.

                • sulfadiazine

                  sulfadiazine will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • sulfamethoxazole

                  sulfamethoxazole will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • sulfisoxazole

                  sulfisoxazole will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • teicoplanin

                  teicoplanin will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • temocillin

                  temocillin will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • tetracycline

                  tetracycline will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • ticarcillin

                  ticarcillin will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • tigecycline

                  tigecycline will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • tobramycin

                  tobramycin will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • torsemide

                  torsemide decreases levels of thiamine by increasing renal clearance. Minor/Significance Unknown.

                • trimethoprim

                  trimethoprim will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • vancomycin

                  vancomycin will decrease the level or effect of thiamine by altering intestinal flora. Applies only to oral form of both agents. Minor/Significance Unknown.

                • vecuronium

                  thiamine increases effects of vecuronium by unspecified interaction mechanism. Minor/Significance Unknown.

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                Adverse Effects

                Frequency Not Defined

                Warmth

                Anaphylaxis

                Cyanosis

                Diaphoresis

                Restlessness

                Angioneurotic edema

                Pruritus

                Urticaria

                Pulmonary edema

                Weakness

                Tightness of the throat

                Nausea

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                Warnings

                Contraindications

                Hypersensitivity

                Cautions

                In pregnancy (doses >RDA)

                Acute thiamine deficiency reported with dextrose administration; use caution when thiamine status uncertain

                Hypersensitivity reactions reported following repeated parenteral doses

                Parenteral products may contain aluminum; use caution in patients with impaired renal function

                Evaluate for additional vitamin deficiencies if patient diagnosed with thiamin deficiency; single vitamin deficiencies are rare

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                Pregnancy & Lactation

                Pregnancy Category: A (injectable); C (if >RDA)

                Lactation: Safe

                Pregnancy Categories

                A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

                B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

                C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

                D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

                X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

                NA: Information not available.

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                Nutrition

                Sources: brewer's yeast, pork, ham, liver, whole grains, peas, beans, milk

                Function: cofactor in glucose metabolism

                Deficiency: (common in alcoholics, Asians, dialysis patients, those on high carbohydrate diet) Beriberi; causes nerve damage, dementia, heart failure; sometimes irreversible

                Reduced/Destroyed by

                Heat-labile thiaminases contained in milled rice, raw shellfish & freshwater fishes

                Heat-stable anti-thiamine factor in coffee/tea

                Sulfite-containing foods

                Alcohol

                High temp

                Toxicity Symptoms

                Toxicity: rare; intake of >400 mg/d; lethargy, balance problems, intestinal problems

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                Pharmacology

                Mechanism of Action

                Forms thiamine pyrophosphate by combining with adenosine triphosphate; essential coenzyme in carbohydrate metabolism

                Pharmacokinetics

                Distribution: Distributes mainly to heart, brain, kidney, and liver

                Excretion: Urine

                Absorption: Adequate (PO); rapid and complete (IM)

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                Administration

                When oral administration is not feasible

                When malabsorption is suspected

                In patients with Wernicke's encephalopathy or high-output heart failure secondary to beriberi

                IV administration preferred for high-output heart failure

                Compatible with most common diluents (dextrose solutions; LR, Ringer's; dextrose-saline solutions; dextrose/LR; NS; ½NS; fat emulsion 10%; Na-lactate 1M/6

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                A Patient Handout is not currently available for this monograph.
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                Formulary

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                The above information is provided for general informational and educational purposes only. Individual plans may vary and formulary information changes. Contact the applicable plan provider for the most current information.

                Tier Description
                1 This drug is available at the lowest co-pay. Most commonly, these are generic drugs.
                2 This drug is available at a middle level co-pay. Most commonly, these are "preferred" (on formulary) brand drugs.
                3 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs.
                4 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
                5 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
                6 This drug is available at a higher level co-pay. Most commonly, these are "non-preferred" brand drugs or specialty prescription products.
                NC NOT COVERED – Drugs that are not covered by the plan.
                Code Definition
                PA Prior Authorization
                Drugs that require prior authorization. This restriction requires that specific clinical criteria be met prior to the approval of the prescription.
                QL Quantity Limits
                Drugs that have quantity limits associated with each prescription. This restriction typically limits the quantity of the drug that will be covered.
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                Drugs that have step therapy associated with each prescription. This restriction typically requires that certain criteria be met prior to approval for the prescription.
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                Drugs that have restrictions other than prior authorization, quantity limits, and step therapy associated with each prescription.
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                Medscape prescription drug monographs are based on FDA-approved labeling information, unless otherwise noted, combined with additional data derived from primary medical literature.