Thiamine

Thiamine Hydrochloride

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Usual Diluents

D5W, NS , Dextrose-saline combinations, LR, D5LR

Standard Dilution [Amount of drug] [Infusion volume] [Infusion rate]

[100 mg] [50 - 100 ml] [15 - 30 minutes]
[250 mg] [100 ml] [30 minutes]
[500 mg] [250 ml] [30-60 minutes]

Wernicke's encephalopathy (treatment):

1] Package insert: in the treatment of Wernicke-Korsakoff syndrome, thiamine hydrochloride has been administered IV in an initial dose of 100 mg, followed by IM doses of 50 to 100 mg daily until the patient is consuming a regular, balanced diet.

2] High dose regimen: 500 mg IV three times per day x 3 days. If patient responds to therapy, continue with 250 mg IM/IV once daily x 5 days or until clinical improvement.

Source: Thomson AD, Cook CC, Touquet R, et al, “The Royal College of Physicians Report on Alcohol: Guidelines for Managing Wernicke’s Encephalopathy in the Accident and Emergency Department,” Alcohol Alcohol, 2002, 37(6):513-21.

Review warnings below.

Stability / Miscellaneous

Stability: 24 hours RT or Ref.

CLINICAL PHARMACOLOGY: The water soluble vitamins are widely distributed in both plants and animals. They are absorbed in man by both diffusion and active transport mechanisms. These vitamins are structurally diverse (derivatives of sugar, pyridine, purines, pyrimidine, organic acid complexes and nucleotide complex) and act as coenzymes, as oxidation-reduction agents, possibly as mitochondrial agents. Metabolism is rapid, and the excess is excreted in the urine. Thiamine is distributed in all tissues. The highest concentrations occur in liver, brain, kidney and heart. When thiamine intake is greatly in excess of need, tissue stores increase two to three times. If intake is insufficient, tissues become depleted of their vitamin content. Absorption of thiamine following IM administration is rapid and complete. Thiamine combines with adenosine triphosphate (ATP) to form thiamine pyrophosphate, also known as cocarboxylase, a coenzyme. Its role in carbohydrate metabolism is the decarboxylation of pyruvic acid in the blood and -ketoacids to acetaldehyde and carbon dioxide. Increased levels of pyruvic acid in the blood indicate vitamin B1 deficiency. The requirement for thiamine is greater when the carbohydrate content of the diet is raised. Body depletion of vitamin B1 can occur after approximately three weeks of total absence of thiamine in the diet.

INDICATIONS AND USAGE: Thiamine hydrochloride injection is effective for the treatment of thiamine deficiency or beriberi whether of the dry (major symptoms related to the nervous system) or wet (major symptoms related to the cardiovascular system) variety. Thiamine hydrochloride injection should be used where rapid restoration of thiamine is necessary, as in Wernicke’s encephalopathy, infantile beriberi with acute collapse, cardiovascular disease due to thiamine deficiency, or neuritis of pregnancy if vomiting is severe. It is also indicated when giving IV dextrose to individuals with marginal thiamine status to avoid precipitation of heart failure. Thiamine hydrochloride injection is also indicated in patients with established thiamine deficiency who cannot take thiamine orally due to coexisting severe anorexia, nausea, vomiting, or malabsorption. Thiamine hydrochloride injection is not usually indicated for conditions of decreased oral intake or decreased gastrointestinal absorption, because multiple vitamins should usually be given.

WARNINGS:
WARNING: This product contains aluminum that may be toxic. Aluminum may reach toxic levels with prolonged parenteral administration if kidney function is impaired. Premature neonates are particularly at risk because their kidneys are immature, and they require large amounts of calcium and phosphate solutions, which contain aluminum. Research indicates that patients with impaired kidney function, including premature neonates, who receive parenteral levels of aluminum at greater than 4 to 5 mcg/kg/day accumulate aluminum at levels associated with central nervous system and bone toxicity. Tissue loading may occur at even lower rates of administration. Serious hypersensitivity/anaphylactic reactions can occur, especially after repeated administration. Deaths have resulted from IV or IM administration of thiamine (see package insert for ADVERSE REACTIONS). Routine testing for hypersensitivity, in many cases, may not detect hypersensitivity. Nevertheless, a skin test should be performed on patients who are suspected of drug allergies or previous reactions to thiamine, and any positive responders should not receive thiamine by injection. If hypersensitivity to thiamine is suspected (based on history of drug allergy or occurrence of adverse reactions after thiamine administration), administer one-hundredth of the dose intradermally and observe for 30 minutes. If no reaction occurs, full dose can be given; the patient should be observed for at least 30 minutes after injection. Be prepared to treat anaphylactic reactions regardless of the precautions taken. Treatment of anaphylactic reactions includes maintaining a patent airway and the use of epinephrine, oxygen, vasopressors, steroids and antihistamines.

DOSAGE AND ADMINISTRATION:
“Wet” beriberi with myocardial failure must be treated as an emergency cardiac condition, and thiamine must be administered slowly by the IV route in this situation (see WARNINGS). In the treatment of beriberi, 10 to 20 mg of thiamine hydrochloride are given IM three times daily for as long as two weeks. (See WARNINGS regarding repeated injection of thiamine.) An oral therapeutic multivitamin preparation containing 5 to 10 mg thiamine, administered daily for one month, is recommended to achieve body tissue saturation. Infantile beriberi that is mild may respond to oral therapy, but if collapse occurs, doses of 25 mg may cautiously be given IV. Poor dietary habits should be corrected and an abundant and well-balanced dietary intake should be prescribed. Patients with neuritis of pregnancy in whom vomiting is severe enough to preclude adequate oral therapy should receive 5 to 10 mg of thiamine hydrochloride IM daily. In the treatment of Wernicke-Korsakoff syndrome, thiamine hydrochloride has been administered IV in an initial dose of 100 mg, followed by IM doses of 50 to 100 mg daily until the patient is consuming a regular, balanced diet. (See WARNINGS regarding repeated injections of thiamine.) Patients with marginal thiamine status to whom dextrose is being administered should receive 100 mg thiamine hydrochloride in each of the first few liters of IV fluid to avoid precipitating heart failure. Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.

HOW SUPPLIED: Product NDC Thiamine No. No. HCl/mL Volume 1302 63323-013-02 100 mg 2 mL 2 mL size is a multiple dose vial, packaged 25 vials per tray. Store at 20° to 25°C (68° to 77°F)
[see USP Controlled Room Temperature]. PROTECT FROM LIGHT. Use only if solution is clear and seal intact.

Reference(s)

Package Insert: Abraxis Pharmaceutical Products. Schaumburg, IL 60173. Revised: July 2006.