Vitamin B6

What it is and how it works

Pyridoxine is converted to pyridoxal 5'-phosphate, a coenzyme in amino-acid metabolism, haem synthesis and the formation of neurotransmitters such as GABA, serotonin and dopamine.

Indications

Prevention and treatment of pyridoxine deficiency, including deficiency caused by drugs such as isoniazid, penicillamine or hydralazine; sideroblastic anaemia responsive to pyridoxine; pyridoxine-dependent seizures (specialist use); treatment of isoniazid overdose (parenteral).

Dosage and administration (summary)

Deficiency: typically 20–50 mg one to three times daily. Prevention of isoniazid neuropathy: 10–25 mg daily. Higher or parenteral doses for sideroblastic anaemia, pyridoxine-dependent seizures or isoniazid overdose are set by the specialist or by protocol.

Contraindications

Hypersensitivity to pyridoxine or to any excipient.

Warnings and precautions

Prolonged use of high doses (generally above 200 mg daily for long periods) can cause sensory peripheral neuropathy. Pyridoxine reduces the effect of levodopa given without a dopa-decarboxylase inhibitor.

Pregnancy

Safe at recommended doses; high doses should be avoided unless medically indicated.

Storage and supply

Store below 25 °C, protected from light.

Source: reference summary prepared from the EU SmPC/EPAR, BNF and WHO Model Formulary. The approved product information in Iran governs.