thiamine

Absorption: Well absorbed from the GI tract by an active process. Excessive amounts are not absorbed completely. Also well absorbed from IM sites.

Distribution: Widely distributed to tissues.

Metabolism/Excretion: Metabolized by the liver. Excess amounts are excreted unchanged by the kidneys.

Half-Life: Unknown.

Time/Action Profile ⬆ ⬇

(time for symptoms of deficiency—edema and heart failure—to resolve‡)

ROUTE	ONSET	PEAK	DURATION
PO, IM, IV	hr	days	days–wk

‡Confusion and psychosis take longer to respond.

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity;
Known alcohol intolerance or bisulfite hypersensitivity (elixir only).

Use Cautiously in:

Wernicke’s encephalopathy (condition may be worsened unless thiamine is administered before glucose).

Adv. Reactions/Side Effects ⬆ ⬇

Adverse reactions and side effects are extremely rare and are usually associated with IV administration or extremely large doses

CV: hypotension, VASCULAR COLLAPSE

Derm: cyanosis, pruritus, sweating, tingling, urticaria, warmth

EENT: tightness of the throat

GI: nausea

Neuro: restlessness, weakness

Resp: pulmonary edema, respiratory distress

Misc: ANGIOEDEMA

Interactions ⬆ ⬇

Drug-drug:

None reported.

Route/Dosage ⬆ ⬇

Thiamine Deficiency (Beriberi)

PO (Adults ): 5–10 mg 3 times daily.
PO (Children ): 10–50 mg/day in divided doses.
IM IV (Adults ): 5–100 mg 3 times daily.
IM IV (Children ): 10–25 mg/day.

Dietary Supplement

PO (Adults ): 1–1.6 mg/day.
PO (Children 4–10 yr): 0.9–1 mg/day.
PO (Children birth–3 yr): 0.3–0.7 mg/day.

Availability ⬆ ⬇

(Generic available)

Tablets: 5 mgOTC; 10 mgOTC; 25 mgOTC; 50 mgOTC; 100 mgOTC; 250 mgOTC; 500 mgOTC
Injection: 100 mg/mL

Assessment ⬆ ⬇

Assess for signs and symptoms of thiamine deficiency (anorexia, GI distress, irritability, palpitations, tachycardia, edema, paresthesia, muscle weakness and pain, depression, memory loss, confusion, psychosis, visual disturbances, elevated serum pyruvic acid levels).
Assess patient’s nutritional status (diet, weight) prior to and during therapy.
Monitor patients receiving IV thiamine for anaphylaxis (wheezing, urticaria, edema).

Lab Test Considerations:

May interfere with certain methods of testing serum theophylline, uric acid, and urobilinogen concentrations.

Implementation ⬆ ⬇

Do not confuse thiamine with Thalomid.
Because of infrequency of single B-vitamin deficiencies, combinations are commonly administered.
IM: IV: Parenteral administration is reserved for patients in whom oral administration is not feasible.
IM: Administration may cause tenderness and induration at injection site. Cool compresses may decrease discomfort.

IV Administration:

IV: Sensitivity reactions and death have occurred from IV administration. An intradermal test dose is recommended in patients with suspected sensitivity. Monitor site for erythema and induration.
Concentration: Administer undiluted at 100 mg/mL.
Rate: Administer at a rate of 100 mg over 5 min.
Diluent: May be diluted in dextrose/Ringer’s or LR combinations, dextrose/saline combinations, D5W, D10W, Ringer’s and LR injection, 0.9% NaCl, or 0.45% NaCl. Usually administered with other vitamins.

Patient/Family Teaching ⬆ ⬇

Encourage patient to comply with dietary recommendations of health care professional. Explain that the best source of vitamins is a well-balanced diet with foods from the four basic food groups.
Teach patient that foods high in thiamine include cereals (whole grain and enriched), meats (especially pork), and fresh vegetables; loss is variable during cooking.
Caution patients self-medicating with vitamin supplements not to exceed RDA. The effectiveness of megadoses of vitamins for treatment of various medical conditions is unproven and may cause side effects.
Rep: Thiamine requirements are increased in during pregnancy, especially in women with prolonged nausea and vomiting. RDA for thiamine during lactation is 1.4 mg.

Evaluation/Desired Outcomes ⬆ ⬇

Prevention of or decrease in the signs and symptoms of vitamin B deficiency.
- Decrease in the symptoms of neuritis, ocular signs, ataxia, edema, and heart failure may be seen within hrs of administration and may disappear within a few days.
- Confusion and psychosis may take longer to respond and may persist if nerve damage has occurred.

US Brand Names ⬆ ⬇

Code ⬆

NDC Code

25021- Sagent Pharmaceuticals
- 25021-500- thiamine hydrochloride
  - 25021-500-02- 25 VIAL in 1 CARTON (25021-500-02) > 2 mL in 1 VIAL

50090- A-S Medication Solutions
- 50090-4407- Thiamine
  - 50090-4407-1- 1 VIAL, MULTI-DOSE in 1 BAG (50090-4407-1) > 2 mL in 1 VIAL, MULTI-DOSE

52584- General Injectables and Vaccines, Inc
- 52584-196- THIAMINE HYDROCHLORIDE
  - 52584-196-00- 1 VIAL, MULTI-DOSE in 1 BAG (52584-196-00) > 2 mL in 1 VIAL, MULTI-DOSE

63323- Fresenius Kabi USA, LLC
- 63323-013- Thiamine
  - 63323-013-02- 25 VIAL, MULTI-DOSE in 1 TRAY (63323-013-02) > 2 mL in 1 VIAL, MULTI-DOSE (63323-013-01)

63323- Fresenius Kabi USA, LLC
- 63323-013- Thiamine
  - 63323-013-09- 25 VIAL, MULTI-DOSE in 1 TRAY (63323-013-09) > 2 mL in 1 VIAL, MULTI-DOSE

63323- Fresenius Kabi USA, LLC
- 63323-013- Thiamine
  - 63323-013-26- 25 VIAL, MULTI-DOSE in 1 TRAY (63323-013-26) > 2 mL in 1 VIAL, MULTI-DOSE

67457- Mylan Institutional LLC
- 67457-196- Thiamine Hydrochloride
  - 67457-196-02- 25 VIAL, MULTI-DOSE in 1 CARTON (67457-196-02) > 2 mL in 1 VIAL, MULTI-DOSE (67457-196-00)

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇

Pharmacokinetics ⬆ ⬇