Thiamine (Vitamin B1) is a co-enzyme in carbohydrate metabolism. It is mainly used to treat the following conditions:

• Beriberi (dry or wet variety)
• The encephalopathy Wernicke
• The absence of thiamine (including thiamine deficiency in pregnancy associated with neuropathy)
• Beriberi in children with a severe collapse
• Heart problems brought on by thiamine deficiencies
• Nutritional supplement.
• Prior to providing Individuals with marginal thiamine status should receive intravenous dextrose to avoid heart failure from developing quickly.Prior to providing Individuals with marginal thiamine status should receive intravenous dextrose to avoid heart failure from developing quickly.

Off Label Use of Thiamine (Vitamin B1) in Adults include:

• Alcohol withdrawal syndrome
• Ethylene glycol poisoning
• Severe sepsis or septic shock

Thiamine (Vitamin B1) Dose in Adults

Treatment of marginal thiamine status with thiamine (Vitamin B1) dosage (to prevent heart failure): Treatment of marginal thiamine status with thiamine (Vitamin B1) dosage (to prevent heart failure):

• In patients with questionable thiamine status who are receiving dextrose, 100 mg of intravenous thiamine is provided to each of the first several litres of intravenous fluid. In patients with questionable thiamine status who are receiving dextrose, 100 mg of intravenous thiamine is provided to each of the first several litres of intravenous fluid.

Parenteral nutrition supplementation :

1. 6 mg/day Intravenous.

Thiamine Dose in the treatment of Thiamine deficiency (beriberi):

• It is given via Intramuscular or Intravenous route 3 times a day @ 5 to 30 mg/dose (if severe illness).
• Then for 30 days, take 5–30 mg orally once, twice, or as directed.

• Manufacturer's labeling:

  • An oral multivitamin pill containing 5 to 10 mg of thiamine should be taken every day for a month after receiving 10 to 20 mg through an intramuscular approach three times per day for 14 days.

Thiamine Dose in the treatment of Alcohol withdrawal syndrome (off-label):

• 100 to 250 mg intramuscularly or intravenously once a day for three to five days, then 100 mg orally three times per day for seven to fourteen days, and finally 100 mg orally every day after that.

Thiamine Dose in the treatment of Ethylene glycol poisoning (off-label):

• 100 mg Intravenous once a day until the intoxication has settled.

Thiamine Dose in the treatment of severe sepsis or septic shock (off-label):

• 200 mg given Intravenously twice a day for over 30 minutes for 4 days or until the patient is discharged from ICU.
• Combined delivery of intravenous hydrocortisone with intravenous ascorbic acid (vitamin C).

Thiamine Dose in the treatment of Wernicke encephalopathy:

• Prophylaxis (off-label):
  • 100–250 mg administered intravenously or intramuscularly once daily for three to five days, then 100 mg taken orally three times a day for seven to fourteen days, and finally 100 mg taken orally every day.
• Treatment:
  • Initial: It is administered intravenously 200–500 mg three times per day for two to seven days.
  • If a thiamine response is found, the dosage should be increased to either 250 mg intravenously or intramuscularly once daily for an additional 3 to 5 days (or until the clinical improvement stops), followed by 30 mg twice daily, or 100 mg orally three times a day for 1 to 2 weeks, then 100 mg orally once daily.
• Manufacturer's labeling:
  • Initially: 100 mg Intravenous, then 50 - 100 mg Intramuscular daily.

Thiamine (Vitamin B1) Dose in Children

Note: Dosage information is given in mcg/kg, mg/kg, and mg/day. Exercise caution.

Thiamine Dose in the treatment of Parenteral nutrition for maintenance requirement:

• Infants:
  • Infants receive an intravenous dose of 0.35 to 0.5 mg/kg/day up to a maximum of 1.2 mg per 24 hours.
• Children:
  • 2 mg/day Intravenous.

Thiamine Dose in the treatment of Thiamine deficiency in critically ill patients (beriberi):

• Infants:
  • Various regimens were reported:
    • It is administered 25 to 50 mg intravenously, then 10 mg intramuscularly every day for seven days, followed by 3 to 5 mg orally every day for at least six weeks.
    • There have also been reports of other regimens with higher beginning doses.

Note: Treatment for thiamine deficiency should also be examined for breastfeeding women.

• Adolescents: Insufficient data available:
  • If a patient is seriously unwell, it can be administered as 100 mg intramuscularly or intravenously once a day for up to 7 days, followed by 10 mg orally once daily.
• Children: Insufficient data available:
  • If seriously unwell, administer 10 mg intramuscularly or intravenously once daily for 7 days, followed by 3 to 5 mg administered orally once daily for at least 6 weeks.

Pregnancy Risk Factor A

• Due to prolonged nausea and vomiting, including hyperemesis gravidarum, pregnant women are at high risk of vitamin B1 deficiencies.
• Water-soluble vitamins can cross the placenta. During pregnancy, Vitamin B1 is needed in greater quantities.
•  Polyneuropathy and Wernicke encephalopathy can be signs of vitamin B1 deficiency.
• Pregnant women with prolonged vomiting should take Vitamin B1 supplementation.
• Wernicke Encephalopathy can be suspected by intravenous drug formulation. Depending on the severity of the condition, Intramuscular or oral therapy may be offered.
• Infusing intravenous fluid to treat hyperemesis gravidarum should include thiamine. This will prevent Wernicke's encephalopathy.

Use during breastfeeding:

• It is excreted from breastmilk. Vitamin B1 levels in breastmilk are similar between mothers who take supplements and those who don't.
• Breastfeeding females require vitamin B1 in greater quantities. 
• A deficiency in vitamin B1 may lead to infants exclusively breastfed who are not receiving enough. 
• Supplementation should be provided to both mother and baby if there is a vitamin B1 deficiency.

Dose in Kidney disease:

• No dosage adjustment is provided in the manufacturer's labeling.

Dose in Liver disease:

• No dosage adjustment is provided in the manufacturer's labeling.

Side effects of Thiamine:

• Dermatologic:
  • Diaphoresis
  • Pruritus
  • Skin sclerosis
  • Urticaria
• Central nervous system:
  • Flushing sensation
  • Restlessness
• Local:
  • Tenderness at the injection site
• Gastrointestinal:
  • Nausea
• Hematologic & oncologic:
  • Haemorrhage (into the gastrointestinal tract)
• Respiratory:
  • Cyanosis
  • Pharyngeal edema
  • Pulmonary edema
• Hypersensitivity:
  • Anaphylaxis
  • Angioedema
  • Hypersensitivity reaction
• Neuromuscular & skeletal:
  • Weakness

Contraindication to Thiamine ( Vitamin B1):

• Allergy to thiamine and any component of the formulation

Warnings and Precautions

• Hypersensitivity reactions
  • Multiple parenteral doses have been linked to severe allergic reactions.
  • It is worth performing a skin test on people with a history of allergic reactions.

Monitoring Parameters:

None required. Monitor for symptomatic improvement.

How to administer Thiamine (Vitamin B1)?

Intramuscular and Intravenous:

• The parenteral formulation may be administered intravenously or intramuscularly. Different administration rates have been described (e.g., 100 mg over 5 minutes).
• For doses more than 100 mg, the prolonged infusion period is chosen. Slow administration over 30 minutes into larger, more proximal veins can lessen local injection responses.
• To stop the development of acute thiamine deficiency symptoms in malnourished patients, it should be administered prior to administering parenteral glucose solutions.

Mechanism of action of Thiamine (Vitamin B1):

• It is a crucial coenzyme for the metabolism of carbohydrates. Thiamine Pyrophosphate is created when it is coupled with adenosine triphosphate.
• Thiamine can be used to treat ethylene glycol poisoning. It is thought that it will increase the formation of glycine, which is a non-toxic metabolite.

Metabolism Hepatic

Absorption It can be absorbed easily orally. It is easy to absorb intramuscularly.

Excretion: Urine (as an unchanged drug or as pyrimidine if body storage sites become saturated).

Distribution: The highest concentrations are found in the brain, heart, kidney and liver

International Brand Names of Thiamine (Vitamin B1):

• Betaxin
• Thiamiject
• Abery
• Actamin
• AFI-B
• Aliaron D 10
• Anerex
• Aneurin-AS
• Arcavit-B1
• B1-ASmedic
• B1-Vicotrat
• Becaps
• Benerva
• Beneuran
• Beneurol
• Beneuron
• Vitamina B1 Biol
• Vitaminum B1
• Bermin B
• Beta-Sol
• Beta-Tabs
• Betabion
• Betamin
• Betamine
• Bevitine
• Bevitol
• Biogen
• Dagravit B1
• Dexabion
• Hiace
• Hithia
• Incremin con Hierro
• Kirin B1
• Lophakomp-B1
• Metabolin
• Mutsutamin
• Neo-Panlacticos
• Neuramin
• Vitamin B1-Hevert
• Vitamin B1Injektopas
• Pagavit
• Pharmaton
• Plivit B1
• Suma-B
• Thiamine Injection
• Tiacur
• Tiamidexal
• Vitamin B1 Jenapharm
• Vitamin B1 Kattwiga
• Tiamin ”Dak”
• Tiamina
• Tiaminal
• Tolima
• Tribedoce
• Trifosfaneurina
• Tyvera
• B1 Agepha
• Vita-B1
• Vitamin B1
• Vitamin B1-ratiopharm
• Vitanon[inj.]

Thiamine (Vitamin B1) brand Names in Pakistan: