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(THYE a min)

Index Terms

  • Aneurine Hydrochloride
  • Thiamin
  • Thiamine HCl
  • Thiamine Hydrochloride
  • Thiaminium Chloride Hydrochloride
  • Vitamin B1

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Capsule, Oral, as hydrochloride:

Generic: 50 mg

Solution, Injection, as hydrochloride:

Generic: 100 mg/mL (2 mL)

Tablet, Oral, as hydrochloride:

Generic: 50 mg, 100 mg, 250 mg

Tablet, Oral, as hydrochloride [preservative free]:

Generic: 100 mg

Pharmacologic Category

  • Vitamin, Water Soluble


An essential coenzyme in carbohydrate metabolism by combining with adenosine triphosphate to form thiamine pyrophosphate


Oral: Adequate; IM: Rapid and complete


Highest concentrations found in brain, heart, kidney, liver


In the liver


Urine (as unchanged drug and as pyrimidine after body storage sites become saturated)

Use: Labeled Indications

Treatment of thiamine deficiency including beriberi, Wernicke's encephalopathy, Korsakoff’s syndrome, neuritis associated with pregnancy, or in alcoholic patients; dietary supplement


Hypersensitivity to thiamine or any component of the formulation

Dosing: Adult

Recommended daily intake:

≥19 years: Females: 1.1 mg; Males: 1.2 mg

Pregnancy, lactation: 1.4 mg

Parenteral nutrition supplementation: 6 mg/day; may be increased to 25-50 mg/day with history of alcohol abuse

Thiamine deficiency (beriberi): 5-30 mg/dose IM or IV 3 times/day (if critically ill); then orally 5-30 mg/day in single or divided doses 3 times/day for 1 month

Alcohol withdrawal syndrome: 100 mg/day IM or IV for several days, followed by 50-100 mg/day orally

Wernicke's encephalopathy: Treatment (manufacturer labeling): Initial: 100 mg IV, then 50-100 mg/day IM or IV until consuming a regular, balanced diet. However, larger doses may be required based on failure of lower doses to produce clinical improvement in some patients.

Alternate dosage: The Royal College of Physicians (U.K.) has recommended the use of higher doses of thiamine (in combination with other B vitamins, ascorbic acid, potassium, phosphate, and magnesium) for the management of Wernicke’s encephalopathy (Thomson, 2002):

Prophylaxis: 250 mg IV once daily for 3-5 days

Treatment: Initial: 500 mg IV 3 times/day for 3 days. If response to thiamine after 3 days, continue with 250 mg IM or IV once daily for an additional 5 days or until clinical improvement.

Dosing: Geriatric

Refer to adult dosing.

Dosing: Pediatric

Adequate Intake:

0-6 months: 0.2 mg/day

7-12 months: 0.3 mg/day

Recommended daily intake:

1-3 years: 0.5 mg

4-8 years: 0.6 mg

9-13 years: 0.9 mg

14-18 years: Females: 1 mg; Males: 1.2 mg

≥19 years: Refer to adult dosing.

Parenteral nutrition supplementation: Infants: 1.2 mg/day

Thiamine deficiency (beriberi): Children: 10-25 mg/dose IM or IV daily (if critically ill), or 10-50 mg/dose orally every day for 2 weeks, then 5-10 mg/dose orally daily for 1 month

Dosing: Renal Impairment

No dosage adjustment provided in manufacturer’s labeling.

Dosing: Hepatic Impairment

No dosage adjustment provided in manufacturer’s labeling.

Extemporaneously Prepared

A 100 mg/mL oral suspension may be made with commercially available thiamine powder. Add 10 g of powder to a mortar. Add small portions of a 1:1 mixture of Ora-Sweet® and Ora-Plus® and mix to a uniform paste; mix while adding the vehicle in equal proportions to almost 100 mL; transfer to a calibrated bottle, rinse mortar with vehicle, and add sufficient quantity of vehicle to make 100 mL. Label "shake well". Stable 91 days under refrigeration or at room temperature.

Ensom MH and Decarie D, "Stability of Thiamine in Extemporaneously Compounded Suspensions," Can J Hosp Pharm, 2005, 58(1):26-30.


Parenteral form may be administered by IM or IV injection. Various rates of administration have been reported (eg, 100 mg over 5 minutes). An extended infusion time is preferred for doses ≥100 mg. Local injection reactions may be minimized by slow administration (~30 minutes) into larger, more proximal veins. Thiamine should be administered prior to parenteral glucose solutions to prevent precipitation of acute symptoms of thiamine deficiency in the poorly nourished.

Dietary Considerations

Dietary sources include legumes, pork, beef, whole grains, yeast, and fresh vegetables. A deficiency state can occur in as little as 3 weeks following total dietary absence.


See Trissel’s IV Compatibility Database


Injection: Store at 15°C to 30°C (59°F to 86°F). Protect from light.

Drug Interactions

There are no known significant interactions.

Test Interactions

False-positive for uric acid using the phosphotungstate method and for urobilinogen using the Ehrlich's reagent; large doses may interfere with the spectrophotometric determination of serum theophylline concentration

Adverse Reactions

Adverse reactions reported with injection. Frequency not defined.

Central nervous system: Flushing sensation, restlessness

Dermatologic: Diaphoresis, pruritus, skin sclerosis (at the injection site following IM administration), urticaria

Gastrointestinal: Nausea

Hematologic & oncologic: Hemorrhage (into the gastrointestinal tract)

Hypersensitivity: Anaphylaxis (following IV administration), angioedema, hypersensitivity reaction (following IV administration)

Local: Tenderness at injection site (following IM administration)

Neuromuscular & skeletal: Weakness

Respiratory: Cyanosis, pharyngeal edema, pulmonary edema


Concerns related to adverse effects:

• Hypersensitivity reactions: Have been reported following repeated parenteral doses; consider skin test in individuals with history of allergic reactions.

Concurrent drug therapy issues:

• Dextrose: Administration of dextrose may precipitate acute symptoms of thiamine deficiency; use caution when thiamine status is marginal or suspect.

Dosage form specific issues:

• Aluminum: The parenteral product may contain aluminum; toxic aluminum concentrations may be seen with high doses, prolonged use, or renal dysfunction. Premature neonates are at higher risk due to immature renal function and aluminum intake from other parenteral sources. Parenteral aluminum exposure of >4 to 5 mcg/kg/day is associated with CNS and bone toxicity; tissue loading may occur at lower doses (Federal Register, 2002). See manufacturer’s labeling.

Other warnings/precautions:

• Parenteral administration: Use with caution with parenteral route (especially IV) of administration.

• Vitamin deficiency: Single vitamin deficiency is rare; evaluate for other deficiencies.

Pregnancy Risk Factor


Pregnancy Considerations

Water soluble vitamins cross the placenta. Thiamine requirements may be increased during pregnancy (IOM, 1998). Severe nausea and vomiting (hyperemesis gravidarum) may lead to thiamine deficiency manifested as Wernicke’s encephalopathy (Chiossi, 2006).

Patient Education

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)

• Patient may experience nausea, sensation of warmth, agitation, sweating a lot, weakness, or injection site irritation. Have patient report immediately to prescriber skin discoloration, black, tarry, or bloody stools, vomiting blood, severe abdominal pain, or shortness of breath (HCAHPS).

• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for health care professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience, and judgment in diagnosing, treating, and advising patients.