Drugs List

Therapeutic Indications

Uses

Vitamin B deficiency

Unlicensed Uses

Congenital lactic acidosis
Nutritional supplement - maple syrup urine disease

Contraindications

None known

Precautions and Warnings

Children under 12 years
Breastfeeding
Galactosaemia
Glucose-galactose malabsorption syndrome
Hereditary fructose intolerance
Lactose intolerance
Pregnancy

Advise patient not to drive until they know how the medicine affects them
Consider prescribing multivitamin preparation
Not all available brands are licensed for use in children under 12 years
Some formulations contain lactose
Some formulations contain sucrose
Vitamin B1 deficiency often coexists with other B vitamin deficiencies
May affect results of some laboratory tests

Pregnancy and Lactation

Pregnancy

Not in all brands, thiamine hydrochloride is considered safe for use during pregnancy.

There is no documented evidence of adverse effects on the foetus or newborn child from taking thiamine hydrochloride during pregnancy.
The recommended daily allowance (RDA) of 1.5mg daily should not be exceeded during pregnancy.

The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14 to 17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).

Lactation

Not in all brands, thiamine hydrochloride is considered safe for use in breastfeeding.

Not known to be harmful but the recommended daily allowance (RDA) of 1.6mg should not be exceeded.

Severely thiamine deficient mothers should avoid breastfeeding as toxic methylglyoxal is excreted in milk.

Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
Specialist advice is available from the UK Drugs in Lactation Advisory Service at https://www.midlandsmedicines.nhs.uk/content.asp?section=6&subsection=17&pageIdx=1

Side Effects

Abdominal pain
Anaphylactic reaction
Angioedema
Diarrhoea
Hives
Hypersensitivity reactions
Itching
Nausea
Palpitations
Pruritus
Respiratory distress
Shock
Tachycardia
Urticaria
Vomiting

Presentation

Oral formulations of thiamine hydrochloride.

Drugs List

Therapeutic Indications

Uses

Vitamin B deficiency

Unlicensed Uses

Congenital lactic acidosis
Nutritional supplement - maple syrup urine disease

Dosage

Adults

Children

Neonates

Contraindications

None known

Precautions and Warnings

Children under 12 years
Breastfeeding
Galactosaemia
Glucose-galactose malabsorption syndrome
Hereditary fructose intolerance
Lactose intolerance
Pregnancy

Advise patient not to drive until they know how the medicine affects them
Consider prescribing multivitamin preparation
Not all available brands are licensed for use in children under 12 years
Some formulations contain lactose
Some formulations contain sucrose
Vitamin B1 deficiency often coexists with other B vitamin deficiencies
May affect results of some laboratory tests

Pregnancy and Lactation

Pregnancy

Not in all brands, thiamine hydrochloride is considered safe for use during pregnancy.

There is no documented evidence of adverse effects on the foetus or newborn child from taking thiamine hydrochloride during pregnancy.
The recommended daily allowance (RDA) of 1.5mg daily should not be exceeded during pregnancy.

The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14 to 17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).

Lactation

Not in all brands, thiamine hydrochloride is considered safe for use in breastfeeding.

Not known to be harmful but the recommended daily allowance (RDA) of 1.6mg should not be exceeded.

Severely thiamine deficient mothers should avoid breastfeeding as toxic methylglyoxal is excreted in milk.

Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
Specialist advice is available from the UK Drugs in Lactation Advisory Service at https://www.midlandsmedicines.nhs.uk/content.asp?section=6&subsection=17&pageIdx=1

Side Effects

Abdominal pain
Anaphylactic reaction
Angioedema
Diarrhoea
Hives
Hypersensitivity reactions
Itching
Nausea
Palpitations
Pruritus
Respiratory distress
Shock
Tachycardia
Urticaria
Vomiting

Effects on Laboratory Tests

Thiamine could give false positive results for urobilinogen by the Ehrlich's reaction. High doses of thiamine may interfere with spectrophotometric assays of theophylline plasma concentration.

Overdosage

It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

The following number will direct the caller to the relevant local centre (0844) 892 0111

Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( www.toxbase.org ) or if this is unavailable at the backup site ( www.toxbasebackup.org ).

Further Information

Last Full Review Date: December 2016

Reference Sources

Drugs During Pregnancy and Lactation: Treatment Options and Risk Assessment, 3rd edition (2015) ed. Schaefer, C., Peters, P. and Miller, R. Elsevier, London.

Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 10th edition (2015) ed. Briggs, G., Freeman, R. Wolters Kluwer Health, Philadelphia.

Martindale: The Complete Drug Reference. 38th Edition. London: Brayfield A (ed). Pharmaceutical Press; 2014.

Summary of Product Characteristics: Benerva 50mg tablets. Teofarma S.r.l. Revised May 2016
Summary of Product Characteristics: Benerva 100mg tablets. Teofarma S.r.l. Revised May 2016

Summary of Product Characteristics: Tyvera 50mg tablets. Auden McKenzie (Pharma Division) Ltd. Revised July 2016.
Summary of Product Characteristics: Tyvera 100mg tablets. Auden McKenzie (Pharma Division) Ltd. Revised July 2016.

Summary of Product Characteristics: Vitamin B1 Tablets 25mg. Nutrition Warehouse Ltd. Revised November 1998

NICE Evidence Services Available at: www.nice.org.uk Last accessed: 24 August 2017