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Prevention and treatment of vitamin B6 deficiency
Hypersensitivity to pyridoxine or any component of the formulation
Recommended daily allowance (RDA): Oral (IOM 1998):
19-50 years: 1.3 mg
≥51 years:
Females: 1.5 mg
Males: 1.7 mg
Pregnancy: 1.9 mg
Lactation: 2 mg
Dietary deficiency: IM, IV: 10-20 mg/day for 3 weeks, followed by oral therapy. Doses up to 600 mg/day may be needed with pyridoxine dependency syndrome.
Gyromitrin-containing mushroom (false morel) overdose/toxicity (treatment/prophylaxis) (off-label use): IV: 25 mg/kg over 15-30 minutes; repeat dose as needed to control seizures (Diaz 2005; Lheureux 2005)
Nausea and vomiting of pregnancy (off-label use): Oral: 10 to 25 mg every 8 hours (Neibyl 2010)
Neurological toxicities (ie, seizures, coma) associated with isoniazid overdose (prevention) (off-label use): IV: Asymptomatic patients who present within 2 hours of ingesting a potentially toxic amount of isoniazid should receive a prophylactic dose of pyridoxine (Hernon 2015). Dosing recommendations are the same as for the treatment of symptomatic patients.
Neurological toxicities (ie, seizures, coma) associated with isoniazid overdose (treatment) (off-label use): IV:
Acute ingestion of known amount: Initial: A total dose of pyridoxine equal to the amount of isoniazid ingested (maximum dose: 5 g); administer at a rate of 0.5 to 1 g/minute until seizures stop or the maximum initial dose has been administered; may repeat every 5 to 10 minutes as needed to control persistent seizure activity and/or CNS toxicity. If seizures stop prior to the administration of the calculated initial dose, infuse the remaining pyridoxine over 4 to 6 hours (Howland 2015; Morrow 2006).
Acute ingestion of unknown amount: Initial: 5 g; administer at a rate of 0.5 to 1 g/minute; may repeat every 5 to 10 minutes as needed to control persistent seizure activity and/or CNS toxicity (Howland 2015; Morrow 2006)
Peripheral neuropathy associated with isoniazid therapy forMycobacterium tuberculosis (prevention): Oral: 25 to 50 mg/day (CDC [Kaplan 2009])
Refer to adult dosing.
Adequate Intake (AI): Oral (IOM 1998): Infants:
1-6 months: 0.1 mg/day
7-12 months: 0.3 mg/day
Recommended daily allowance (RDA): Oral (IOM 1998): Children:
1-3 years: 0.5 mg
4-8 years: 0.6 mg
9-13 years: 1 mg
14-18 years:
Females: 1.5 mg
Males: 1.3 mg
Gyromitrin-containing mushroom (false morel) overdose/toxicity (treatment/prophylaxis) (off-label use): Children and Adolescents: Refer to adult dosing.
Neurological toxicities (ie, seizures, coma) associated with isoniazid overdose (prevention) (off-label use): Refer to adult dosing.
Neurological toxicities (ie, seizures, coma) associated with isoniazid overdose (treatment) (off-label use): IV: Children and Adolescents:
Acute ingestion of known amount: Initial: A total dose of pyridoxine equal to the amount of isoniazid ingested (maximum dose: 70 mg/kg, up to 5 g); administer at a rate of 0.5 to 1 g/minute until seizures stop or the maximum initial dose has been administered; may repeat every 5 to 10 minutes as needed to control persistent seizure activity and/or CNS toxicity. If seizures stop prior to the administration of the calculated initial dose, infuse the remaining pyridoxine over 4 to 6 hours (Howland 2015; Morrow 2006).
Acute ingestion of unknown amount: Initial: 70 mg/kg (maximum dose: 5 g); administer at a rate of 0.5 to 1 g/minute; may repeat every 5 to 10 minutes as needed to control persistent seizure activity and/or CNS toxicity (Howland 2015; Morrow 2006; Santucci 1999)
Burning may occur at the injection site after IM administration.
Gyromitrin-containing mushroom (false morel) overdose/toxicity (treatment/prophylaxis) (off-label use): Administer dose over 15 to 30 minutes (Lheureux 2005).
Isoniazid toxicity (off-label use): Initial doses should be administered at a rate of 0.5 to 1 g/minute. If the parenteral formulation is not available, anecdotal reports suggest that pyridoxine tablets may be crushed and made into a slurry and given at the same dose orally or via nasogastric (NG) tube (Hernon 2015). Oral administration is not recommended for acutely poisoned patients with seizure activity.
Injection: Store at 20 ‚ °C to 25 ‚ °C (68 ‚ °F to 77 ‚ °F). Protect from light.
Excipient information presented when available (limited, particularly for generics); consult specific product labeling.
Capsule, Oral, as hydrochloride:
Neuro-K-250 T.D.: 250 mg [corn free, rye free, starch free, sugar free, wheat free]
Solution, Injection, as hydrochloride:
Generic: 100 mg/mL (1 mL)
Tablet, Oral, as hydrochloride:
Neuro-K-50: 50 mg
Neuro-K-500: 500 mg
Neuro-K-250 Vitamin B6: 250 mg
Pyri 500: 500 mg
Generic: 25 mg, 50 mg, 100 mg, 250 mg
Tablet, Oral, as hydrochloride [preservative free]:
Generic: 25 mg, 50 mg, 100 mg
Tablet Extended Release, Oral, as hydrochloride:
Generic: 200 mg
A 1 mg/mL oral solution may be made using pyridoxine injection. Withdraw 100 mg (1 mL of a 100 mg/mL injection) from a vial with a needle and syringe; add to 99 mL simple syrup in an amber bottle. Label refrigerate". Stable for 30 days refrigerated.
Nahata MC, Pai VB, and Hipple TF, Pediatric Drug Formulations, 5th ed, Cincinnati, OH: Harvey Whitney Books Co, 2004.Stable in fat emulsion 10%.
Altretamine: Pyridoxine may diminish the therapeutic effect of Altretamine. Specifically when altretamine is used in combination with Cisplatin the response duration may be diminished. Consider therapy modification
Barbiturates: Pyridoxine may increase the metabolism of Barbiturates. Apparent in high pyridoxine doses (eg, 200 mg/day) Monitor therapy
Fosphenytoin: Pyridoxine may increase the metabolism of Fosphenytoin. This is most apparent in high pyridoxine doses (e.g., 80 mg to 200 mg daily) Monitor therapy
Levodopa: Pyridoxine may diminish the therapeutic effect of Levodopa. Management: The concomitant use of pyridoxine and levodopa (in the absence of a dopa decarboxylase inhibitor (DDI)) should be avoided. Use of a DDI (e.g., carbidopa) with levodopa will essentially eliminate the risk of this interaction. Consider therapy modification
Phenytoin: Pyridoxine may increase the metabolism of Phenytoin. This is most apparent in high pyridoxine doses (e.g., 80 mg to 200 mg daily) Monitor therapy
For treatment of isoniazid or Gyromitrin-containing mushroom toxicity: Anion gap, arterial blood gases, electrolytes, neurological exam, seizure activity
False positive urobilinogen spot test using Ehrlichs reagent
Frequency not defined.
Central nervous system: Headache, seizure (following very large IV doses), somnolence
Endocrine & metabolic: Acidosis, folic acid decreased
Gastrointestinal: Nausea
Hepatic: AST increased
Neuromuscular & skeletal: Neuropathy, paresthesia
Miscellaneous: Allergic reactions
Warnings related to adverse effects:
- Neuropathy: Severe, permanent peripheral neuropathies have been reported; neurotoxicity is more common with long-term administration of large doses (>2 g/day).
Dosage form specific issues:
- Aluminum: The parenteral product may contain aluminum; toxic aluminum concentrations may be seen with high doses, prolonged use, or renal dysfunction. Premature neonates are at higher risk due to immature renal function and aluminum intake from other parenteral sources. Parenteral aluminum exposure of >4 to 5 mcg/kg/day is associated with CNS and bone toxicity; tissue loading may occur at lower doses (Federal Register 2002). See manufacturer 's labeling.
Other warnings/precautions:
- Dependence/withdrawal: Doses >200 mg/day may cause dependence and withdrawal.
- Pharmacy supply of emergency antidotes: Guidelines suggest that at least 8-24 g be stocked. This is enough to treat 1 patient weighing 100 kg for an initial 8- to 24-hour period. In areas where tuberculosis is common, hospitals should consider stocking 24 g. This is enough to treat 1 patient for 24 hours (Dart 2009).
- Vitamin deficiency: Single vitamin deficiency is rare; evaluate for other deficiencies.
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Water soluble vitamins cross the placenta. Maternal pyridoxine plasma concentrations may decrease as pregnancy progresses and requirements may be increased in pregnant women (IOM 1998). Pyridoxine is used to treat nausea and vomiting of pregnancy (Neibyl 2010). In general, medications used as antidotes should take into consideration the health and prognosis of the mother; antidotes should be administered to pregnant women if there is a clear indication for use and should not be withheld because of fears of teratogenicity (Bailey 2003).
Precursor to pyridoxal, which functions in the metabolism of proteins, carbohydrates, and fats; pyridoxal also aids in the release of liver and muscle-stored glycogen and in the synthesis of GABA (within the central nervous system) and heme
Enteral, parenteral: Readily from the GI tract; primarily in jejunum
Hepatic to pyridoxal phosphate and pyridoxamine phosphate (active forms)
Urine (as metabolites)
Biologic: 15-20 days
- Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)
- Have patient report immediately to prescriber burning or numbness feeling (HCAHPS).
- Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.
Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for health care professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience, and judgment in diagnosing, treating, and advising patients.