Drugs List

Therapeutic Indications

Uses

Treatment and prophylaxis of isoniazid-induced peripheral neuritis.
Treatment of idiopathic sideroblastic anaemia.
Treatment of pyridoxine (vitamin B6) deficiency.

Unlicensed Uses

Metabolic diseases including cystathioninuria and homocystinuria.
Prevention of penicillamine-induced neuropathy in Wilson's disease.
Treatment of premenstrual syndrome.

Administration

For oral use.

Contraindications

None known.

Precautions and Warnings

Pregnancy ( see 'Pregnancy' section )

Children under 18 years of age

If symptoms persist or worsen, advise patient to seek medical advice.

The safety of long term pyridoxine supplementation with doses above 10mg daily has not been established. In particular, the long-term use of pyridoxine in doses above 200mg daily has been associated with neuropathy.

Pregnancy and Lactation

Pregnancy

Pyridoxine is an essential co-enzyme involved in the metabolism of amino acids, carbohydrates and lipids. Pyridoxine is actively transported to the foetus. Concentrations of pyridoxine are higher in the foetus and newborn than in the mother and are directly proportional to maternal intake (approximate newborn: maternal ratio is thought to be 2:1). Information from studies on exposed pregnancies indicate no adverse effects of pyridoxine at normal therapeutic doses on pregnancy or on the health of the foetus or newborn child.

The manufacturer recommends that pyridoxine is used with caution 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 14-17 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 at ( https://www.toxbase.org/ ) or if this is unavailable at the backup site ( https://www.TOXBASEbackup.org/ ).

Licensed in pregnancy? - Yes

Recommended for use in pregnancy? - Yes, where vitamin supplementation required

Known human teratogen? - No

Crosses placenta? - Yes

Lactation

Pyridoxine is an essential co-enzyme involved in the metabolism of amino acids, carbohydrates and lipids. It is excreted into breast milk in concentrations directly proportional to maternal intake. Although there have been some concerns over the lactation-inhibiting effect of very high doses (600mg/day) of pyridoxine, this is not relevant to normal physiological doses, nor to its licensed therapeutic uses.

The manufacturer advises that there are no adverse effects of pyridoxine at therapeutic doses on lactation.

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

Drug excreted in breast milk? - Yes

UK Drugs in Lactation Advisory Service Classification - Suitable for use

Drug known to affect lactation? - Not in therapeutic doses

Side Effects

Severe peripheral neuritis has been reported with long term administration at high doses.

Presentation

Tablets containing 10mg pyridoxine hydrochloride.
Tablets containing 20mg pyridoxine hydrochloride.
Tablets containing 50mg pyridoxine hydrochloride.

Some products are sold as food supplements.

Drugs List

Therapeutic Indications

Uses

Treatment and prophylaxis of isoniazid-induced peripheral neuritis.
Treatment of idiopathic sideroblastic anaemia.
Treatment of pyridoxine (vitamin B6) deficiency.

Unlicensed Uses

Metabolic diseases including cystathioninuria and homocystinuria.
Prevention of penicillamine-induced neuropathy in Wilson's disease.
Treatment of premenstrual syndrome.

Dosage

Adults

Children

Neonates

Administration

For oral use.

Contraindications

None known.

Precautions and Warnings

Pregnancy ( see 'Pregnancy' section )

Children under 18 years of age

If symptoms persist or worsen, advise patient to seek medical advice.

The safety of long term pyridoxine supplementation with doses above 10mg daily has not been established. In particular, the long-term use of pyridoxine in doses above 200mg daily has been associated with neuropathy.

Pregnancy and Lactation

Pregnancy

Pyridoxine is an essential co-enzyme involved in the metabolism of amino acids, carbohydrates and lipids. Pyridoxine is actively transported to the foetus. Concentrations of pyridoxine are higher in the foetus and newborn than in the mother and are directly proportional to maternal intake (approximate newborn: maternal ratio is thought to be 2:1). Information from studies on exposed pregnancies indicate no adverse effects of pyridoxine at normal therapeutic doses on pregnancy or on the health of the foetus or newborn child.

The manufacturer recommends that pyridoxine is used with caution 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 14-17 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 at ( https://www.toxbase.org/ ) or if this is unavailable at the backup site ( https://www.TOXBASEbackup.org/ ).

Licensed in pregnancy? - Yes

Recommended for use in pregnancy? - Yes, where vitamin supplementation required

Known human teratogen? - No

Crosses placenta? - Yes

Lactation

Pyridoxine is an essential co-enzyme involved in the metabolism of amino acids, carbohydrates and lipids. It is excreted into breast milk in concentrations directly proportional to maternal intake. Although there have been some concerns over the lactation-inhibiting effect of very high doses (600mg/day) of pyridoxine, this is not relevant to normal physiological doses, nor to its licensed therapeutic uses.

The manufacturer advises that there are no adverse effects of pyridoxine at therapeutic doses on lactation.

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

Drug excreted in breast milk? - Yes

UK Drugs in Lactation Advisory Service Classification - Suitable for use

Drug known to affect lactation? - Not in therapeutic doses

Effects on Ability to Drive and Operate Machinery

There are no effects on the ability to drive or operate machinery.

Counselling

Advise the patient to seek medical advice if symptoms persist or worsen.

Side Effects

Severe peripheral neuritis has been reported with long term administration at high doses.

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 ( https://www.toxbase.org/ ) or if this is unavailable at the backup site ( https://www.TOXBASEbackup.org/ ).

Shelf Life and Storage

Do not store above 25 degrees C
Protect from light and moisture

Further Information

Last Full review Date: November 2008

Reference Sources

Martindale: The Complete Drug Reference, 35th edition (2007) ed. Sweetman, S. Pharmaceutical Press, London.

Medications and Mother's Milk, 12th edition (2006) Hale, T.W. Hale Publishing, Amarillo, Texas.

Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 8th edition (2008) ed. Briggs, G., Freeman, R. and Yaffe, S. Lippincott Williams & Wilkins, Philadelphia.

Summary of Product Characteristics: Pyridoxine 50mg tablets. Wockhardt UK Ltd. Revised June 2007

NICE Evidence Services Available at: www.nice.org.uk Last accessed: 14 September 2017

UK Drugs in Lactation Advisory Service.
Available at: https://www.ukmicentral.nhs.uk/drugpreg/qrg_p1.asp
Last accessed: 11th November 2008