Vitamin B₆ (Pyridoxine)

Category:

• Vitamin

Description:

• Dietary supplement; water-soluble vitamin

Indications:

• Vitamin B₆ deficiency

  • seen in some breast-fed infants, elderly, oral contraceptive users, alcoholics

• necessary for proper red blood cell production

• Adjunct to Isoniazid (INH) therapy

• Unlabed uses:

  • hydrazine poisoing

  • premenstrual syndrome

  • hyperoxaluria type I

  • nausea and vomiting in pregnancy

Contraindications:

Precautions:

• Pregnancy category A

• Patients may develop hypervitaminosis B₆ with excessive dosages.  Symtoms of hypervitaminosis B₆ are ataxia and severe sensory neuropathy.  This takes up to six months to normalize once discontinued.

Adverse Reactions (Side Effects):

• Relatively non-toxic in therapeutic doses

• Sensory neuropathic syndrome (unstable gait, numb feet, awkward hands, perioral numbness, decreased touch sensations, paresthesia)

• Low serum folic acid levels  

Dosage:

• Dietary sources: meats, cereals, lentils, nuts, bananas, avocados, potatoes

• Administered in oral soft gelatin capsules or injection

• Dietary supplementation (RDA: recommended daily allowance):

  • Adult males: 2m per day

  • Adults females: 1.6m per day

• Dietary deficiency: 10-20mg per day for 3 weeks

• Vitamin B₆ dependency syndrome: 600mg per day initially, then 30mg per day for life

• Isoniazid deficiency: 50-200mg per day

• Isoniazid poisoning: 4 grams IV initial, followed by 1 gram IM every 30 minutes