WHO Model Prescribing Information: Drugs Used in Mycobacterial Diseases
(1991; 44 pages) [French] [Spanish] View the PDF document
Table of Contents
View the documentPreface
Close this folderTuberculosis
View the documentIsoniazid
View the documentPyridoxine
View the documentRifampicin
View the documentRifampicin/isoniazid
View the documentPyrazinamide
View the documentStreptomycin
View the documentEthambutol
View the documentThioacetazone/isoniazid
View the documentBCG vaccine (dried)
View the documentTuberculin (purified protein derivative)
Open this folder and view contentsLeprosy
Open this folder and view contentsNontuberculous mycobacterial diseases


Group: vitamin
Tablet 10 mg (hydrochloride)

General information

Pyridoxine is the naturally occurring form of vitamin B6. Following absorption from the gastrointestinal tract, it is converted in the liver to a coenzyme, pyridoxal phosphate, that is involved in many metabolic processes. Isoniazid interferes competitively with pyridoxine metabolism by inhibiting the formation of the active form of the vitamin, and hence often results in peripheral neuropathy.

Clinical information


To prevent the development of peripheral neuropathy in patients receiving isoniazid.

Dosage and administration

Adults and children: 10 mg daily suffices for prophylaxis but patients with evidence of vitamin B6 deficiency may require up to 50 mg daily.


Pyridoxine can block the therapeutic effect of levodopa by enhancing its decarboxylation to dopamine, which does not enter the brain. However, it does not interfere with the combined preparations of levodopa and a decarboxylase inhibitor.


Pyridoxine tablets should be stored in well-closed containers.

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