Correction of B6 deficiency; restoration of neuronal GABA in isoniazid poisoning.
Precursor of pyridoxal-5-phosphate (PLP), co-enzyme of glutamic acid decarboxylase (glutamate → GABA), transaminase and heme synthase.
Jejunal active (transporter) and passive diffusion absorption; high bioavailability; IV dose in emergency.
Hepatic and tissue phosphorylation to PLP; oxidation to 4-pyridoxic acid; renal excretion.
~ 15–20 days (body stores); PLP ~ 1–3 days.
No documented drug–drug interactions for this medicine.
Pyridoxine is better tolerated with food (reduces nausea); chronic high doses can cause sensory neuropathy — food does not interfere clinically.
Take with food; do not exceed 100 mg/day chronically without guidance (site monograph).
Site monograph (pyridoxine — doses ≥ 10 mg/day can mask B12 deficiency).
No documented disease interactions.
No restrictive Annex 1 entry (l. 41338); vitamin B6 is compatible with pregnancy and has documented use in nausea and vomiting of pregnancy (alone or with doxylamine). Very high prolonged doses (>500 mg/day) can cause maternal peripheral neuropathy.
Compatible at usual doses (10–25 mg 3×/day for pregnancy nausea); avoid chronic megadoses.
May suppress lactation at high doses (Prontuário, Annex 2, l. 43039); at usual supplementation doses, compatible.
Prontuário Terapêutico INFARMED — Annex 1: "Pyridoxine" (l. 41338); Annex 2: "May suppress lactation" (l. 43039). 11.3.2 (Water-soluble vitamins).
Clinical and educational support tool. The information does not replace a medical prescription or the opinion of a qualified healthcare professional.
Medicines from the same therapeutic group (ATC classification) or the same pharmacological class.
