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Accession NumberDB00165  (APRD00204, NUTR00002)
TypeSmall Molecule
GroupsApproved, Nutraceutical

Pyridoxine is the 4-methanol form of vitamin B6 and is converted to pyridoxal 5-phosphate in the body. Pyridoxal 5-phosphate is a coenzyme for synthesis of amino acids, neurotransmitters (serotonin, norepinephrine), sphingolipids, aminolevulinic acid. Although pyridoxine and vitamin B6 are still frequently used as synonyms, especially by medical researchers, this practice is erroneous and sometimes misleading. [PubChem]

2-Methyl-3-hydroxy-4,5-dihydroxymethylpyridineNot AvailableNot Available
3-hydroxy-4,5-bis(hydroxymethyl)-2-methylpyridineNot AvailableNot Available
3-Hydroxy-4,5-dimethylol-alpha-picolineNot AvailableNot Available
5-Hydroxy-6-methyl-3,4-pyridinedimethanolNot AvailableNot Available
PyridoxineNot AvailableNot Available
PyridoxolNot AvailableNot Available
Vitamin B6Not AvailableNot Available
Prescription ProductsNot Available
Generic Prescription Products
NameDosageStrengthRouteLabellerMarketing StartMarketing End
Pyridoxine Hydrochlorideinjection, solution100 mg/mLintramuscular; intravenousAPP Pharmaceuticals, LLC1972-08-14Not AvailableUs 0a2ef1ad1c84951dc1392a8bbe1f3cb241c91ed59e44ad8268635315440d978c
Over the Counter ProductsNot Available
International Brands
BecilanNot Available
BeesixNot Available
BenadonNot Available
BonasanitNot Available
Hexa-BetalinNot Available
HexobionNot Available
NestrexNot Available
Brand mixtures
Brand NameIngredients
DICLEGISPyridoxine + Doxylamine
Pyridoxine hydrochloride
  • Monoisotopic Mass: 205.050570962
  • Average Mass: 205.639
CAS number65-23-6
WeightAverage: 169.1778
Monoisotopic: 169.073893223
Chemical FormulaC8H11NO3
DescriptionThis compound belongs to the class of organic compounds known as pyridoxines. These are pyridoxal derivatives in which the carbaldehyde group at position 2 of the pyridoxal moiety is replaced by a hydroxymethyl group.
KingdomOrganic compounds
Super ClassOrganoheterocyclic compounds
ClassPyridines and derivatives
Sub ClassPyridoxines
Direct ParentPyridoxines
Alternative Parents
  • Pyridoxine
  • Methylpyridine
  • Hydroxypyridine
  • Heteroaromatic compound
  • Azacycle
  • Hydrocarbon derivative
  • Aromatic alcohol
  • Primary alcohol
  • Organooxygen compound
  • Organonitrogen compound
  • Alcohol
  • Aromatic heteromonocyclic compound
Molecular FrameworkAromatic heteromonocyclic compounds
External Descriptors
IndicationFor the treatment of vitamin B6 deficiency and for the prophylaxis of isoniazid-induced peripheral neuropathy.
PharmacodynamicsVitamin B6 (pyridoxine) is a water-soluble vitamin used in the prophylaxis and treatment of vitamin B6 deficiency and peripheral neuropathy in those receiving isoniazid (isonicotinic acid hydrazide, INH). Vitamin B6 has been found to lower systolic and diastolic blood pressure in a small group of subjects with essential hypertension. Hypertension is another risk factor for atherosclerosis and coronary heart disease. Another study showed pyridoxine hydrochloride to inhibit ADP- or epinephrine-induced platelet aggregation and to lower total cholesterol levels and increase HDL-cholesterol levels, again in a small group of subjects. Vitamin B6, in the form of pyridoxal 5'-phosphate, was found to protect vascular endothelial cells in culture from injury by activated platelets. Endothelial injury and dysfunction are critical initiating events in the pathogenesis of atherosclerosis. Human studies have demonstrated that vitamin B6 deficiency affects cellular and humoral responses of the immune system. Vitamin B6 deficiency results in altered lymphocyte differentiation and maturation, reduced delayed-type hypersensitivity (DTH) responses, impaired antibody production, decreased lymphocyte proliferation and decreased interleukin (IL)-2 production, among other immunologic activities.
Mechanism of actionVitamin B6 is the collective term for a group of three related compounds, pyridoxine (PN), pyridoxal (PL) and pyridoxamine (PM), and their phosphorylated derivatives, pyridoxine 5'-phosphate (PNP), pyridoxal 5'-phosphate (PLP) and pyridoxamine 5'-phosphate (PMP). Although all six of these compounds should technically be referred to as vitamin B6, the term vitamin B6 is commonly used interchangeably with just one of them, pyridoxine. Vitamin B6, principally in its biologically active coenzyme form pyridoxal 5'-phosphate, is involved in a wide range of biochemical reactions, including the metabolism of amino acids and glycogen, the synthesis of nucleic acids, hemogloblin, sphingomyelin and other sphingolipids, and the synthesis of the neurotransmitters serotonin, dopamine, norepinephrine and gamma-aminobutyric acid (GABA).
AbsorptionThe B vitamins are readily absorbed from the gastrointestinal tract, except in malabsorption syndromes. Pyridoxine is absorbed mainly in the jejunum.
Volume of distributionNot Available
Protein binding22%


Route of eliminationNot Available
Half life15-20 days
ClearanceNot Available
ToxicityOral Rat LD50 = 4 gm/kg. Toxic effects include convulsions, dyspnea, hypermotility, diarrhea, ataxia and muscle weakness.
Affected organisms
  • Humans and other mammals
PathwayCategorySMPDB ID
Vitamin B6 MetabolismMetabolicSMP00017
SNP Mediated EffectsNot Available
SNP Mediated Adverse Drug ReactionsNot Available
Predicted ADMET features
Human Intestinal Absorption+0.9728
Blood Brain Barrier+0.6889
Caco-2 permeable-0.8958
P-glycoprotein substrateNon-substrate0.5579
P-glycoprotein inhibitor INon-inhibitor0.9723
P-glycoprotein inhibitor IINon-inhibitor0.9221
Renal organic cation transporterNon-inhibitor0.8177
CYP450 2C9 substrateNon-substrate0.7386
CYP450 2D6 substrateNon-substrate0.781
CYP450 3A4 substrateNon-substrate0.7104
CYP450 1A2 substrateNon-inhibitor0.9046
CYP450 2C9 substrateNon-inhibitor0.9071
CYP450 2D6 substrateNon-inhibitor0.923
CYP450 2C19 substrateNon-inhibitor0.9025
CYP450 3A4 substrateNon-inhibitor0.8648
CYP450 inhibitory promiscuityLow CYP Inhibitory Promiscuity0.695
Ames testNon AMES toxic0.9133
BiodegradationNot ready biodegradable0.5678
Rat acute toxicity1.6573 LD50, mol/kg Not applicable
hERG inhibition (predictor I)Weak inhibitor0.8454
hERG inhibition (predictor II)Non-inhibitor0.8734
  • Eli lilly and co
  • Akorn inc
  • App pharmaceuticals llc
  • Bel mar laboratories inc
  • Dell laboratories inc
  • Elkins sinn div ah robins co inc
  • Luitpold pharmaceuticals inc
  • Watson laboratories inc
Dosage forms
Injection, solutionintramuscular; intravenous100 mg/mL
Unit descriptionCostUnit
Pyridoxine HCl 100 50 mg tablet Bottle12.99USD bottle
Pyridoxine HCl 100 mg/ml vial11.69USD vial
Pyridoxine 100 mg/ml vial10.79USD ml
Pyridoxine hcl crystals6.94USD g
Pyridoxine 500 mg tablet0.18USD tablet
Pyridoxine 25 mg tablet0.14USD tablet
Neuro k 500 mg tablet0.13USD tablet
Pyridoxine 250 mg tablet0.13USD tablet
CVS Pharmacy vitamin b-6 200 mg tablet0.07USD tablet
Neuro-k 250 mg tablet0.06USD tablet
Pyridoxine 50 mg tablet0.06USD tablet
Vitamin b-6 100 mg tablet0.04USD tablet
CVS Pharmacy vitamin b-6 100 mg tablet0.03USD tablet
Pyridoxine 100 mg tablet0.03USD tablet
Vitamin b6 50 mg tablet0.03USD tablet
Vitamin b-6 50 mg tablet0.03USD tablet
CVS Pharmacy vitamin b-6 50 mg tablet0.02USD tablet
Vitamin b-6 25 mg tablet0.02USD tablet
DrugBank does not sell nor buy drugs. Pricing information is supplied for informational purposes only.
PatentsNot Available
Experimental Properties
melting point159-162 °CPhysProp
water solubility2.2E+005 mg/LNot Available
logP-0.77SANGSTER (1993)
Predicted Properties
Water Solubility16.1 mg/mLALOGPS
pKa (Strongest Acidic)9.4ChemAxon
pKa (Strongest Basic)5.58ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count4ChemAxon
Hydrogen Donor Count3ChemAxon
Polar Surface Area73.58 Å2ChemAxon
Rotatable Bond Count2ChemAxon
Refractivity44.11 m3·mol-1ChemAxon
Polarizability17.11 Å3ChemAxon
Number of Rings1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
Mass Spec (NIST)Not Available
Synthesis Reference

Harumi Kita, “Production of pyridoxine.” U.S. Patent US4339586, issued October, 1972.

General ReferenceNot Available
External Links
ATC CodesNot Available
AHFS Codes
  • 88:08.00
  • 92:02.00*
PDB Entries
FDA labelNot Available
MSDSDownload (51.5 KB)
Drug Interactions
AltretaminePyridoxine may diminish the therapeutic effect of Altretamine. Specifically when altretamine is used in combination with Cisplatin the response duration may be diminished.
AmobarbitalMay increase the metabolism of Barbiturates. Apparent in high pyridoxine doses (eg, 200 mg/day)
ButabarbitalPyridoxine may increase the metabolism of Barbiturates. Apparent in high pyridoxine doses (eg, 200 mg/day)
ButalbitalMay increase the metabolism of Barbiturates. Apparent in high pyridoxine doses (eg, 200 mg/day)
ButethalPyridoxine may increase the metabolism of Barbiturates. Apparent in high pyridoxine doses (eg, 200 mg/day)
FosphenytoinPyridoxine may increase the metabolism of Fosphenytoin. This is most apparent in high pyridoxine doses (e.g., 80 mg to 200 mg daily)
HeptabarbitalPyridoxine may increase the metabolism of Barbiturates. Apparent in high pyridoxine doses (eg, 200 mg/day)
HexobarbitalPyridoxine may increase the metabolism of Barbiturates. Apparent in high pyridoxine doses (eg, 200 mg/day)
MethohexitalPyridoxine may increase the metabolism of Barbiturates. Apparent in high pyridoxine doses (eg, 200 mg/day)
PentobarbitalPyridoxine may increase the metabolism of Barbiturates. Apparent in high pyridoxine doses (eg, 200 mg/day)
PhenobarbitalMay increase the metabolism of Barbiturates. Apparent in high pyridoxine doses (eg, 200 mg/day)
PhenytoinPyridoxine may increase the metabolism of Phenytoin. This is most apparent in high pyridoxine doses (e.g., 80 mg to 200 mg daily)
PrimidonePyridoxine may increase the metabolism of Barbiturates. Apparent in high pyridoxine doses (eg, 200 mg/day)
SecobarbitalPyridoxine may increase the metabolism of Barbiturates. Apparent in high pyridoxine doses (eg, 200 mg/day)
Food InteractionsNot Available


1. Pyridoxal kinase

Kind: protein

Organism: Human

Pharmacological action: yes

Actions: ligand


Name UniProt ID Details
Pyridoxal kinase O00764 Details


  1. Adams JB, George F, Audhya T: Abnormally high plasma levels of vitamin B6 in children with autism not taking supplements compared to controls not taking supplements. J Altern Complement Med. 2006 Jan-Feb;12(1):59-63. Pubmed
  2. Newman JA, Das SK, Sedelnikova SE, Rice DW: The crystal structure of an ADP complex of Bacillus subtilis pyridoxal kinase provides evidence for the parallel emergence of enzyme activity during evolution. J Mol Biol. 2006 Oct 20;363(2):520-30. Epub 2006 Aug 12. Pubmed
  3. Kim SY, An JJ, Kim DW, Choi SH, Lee SH, Hwang SI, Kwon OS, Kang TC, Won MH, Cho SW, Park J, Eum WS, Lee KS, Choi SY: Tat-mediated protein transduction of human brain pyridoxine-5-P oxidase into PC12 cells. J Biochem Mol Biol. 2006 Jan 31;39(1):76-83. Pubmed
  4. Nagahashi Y, Tazoe M, Hoshino T: Cloning of the pyridoxine 5’-phosphate phosphatase gene (pdxP) and vitamin B6 production in pdxP recombinant Sinorhizobium meliloti. Biosci Biotechnol Biochem. 2008 Feb;72(2):421-7. Epub 2008 Feb 7. Pubmed


1. Cytochrome P450 1A1

Kind: protein

Organism: Human

Pharmacological action: no

Actions: inhibitor


Name UniProt ID Details
Cytochrome P450 1A1 P04798 Details


  1. Tangjarukij C, Navasumrit P, Zelikoff JT, Ruchirawat M: The effects of pyridoxine deficiency and supplementation on hematological profiles, lymphocyte function, and hepatic cytochrome P450 in B6C3F1 mice. J Immunotoxicol. 2009 Sep;6(3):147-60. doi: 10.1080/15476910903083866. Pubmed

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Drug created on June 13, 2005 07:24 / Updated on September 24, 2013 13:55