Documentation and Sources

Introduction to DrugBank

DrugBank is a detailed database on small molecule and biotech drugs. Each drug entry ("DrugCard") includes extensive information on properties, structure, and biology (what the drug does in the body). Below you can find some definitions, and a detailed reference of the sources used for each field.

Drug Type

Drugs are categorized by type, which determines their origin. Here is the list of possible types:

Small Molecule

Low molecular weight drugs (900 daltons) which are produced by chemical synthesis. These drugs have well defined structures and chemical properties. In DrugBank, some drugs larger than 900 daltons are considered small molecule drugs (such as monomers: ribo- or deoxyribonucleotides, amino acids, and monosaccharides), as long as they are chemically synthesized.


Drugs with a biological origin (manufactured in, extracted from, or semisynthesized from biological sources). These include vaccines, blood, blood components, allergenics, somatic cells, gene therapies, tissues, recombinant therapeutic protein, and living cells used in cell therapy. Biotech drugs are also known as biopharmaceuticals or biologics.

Drug Group(s)

Drugs are categorized by group, which determines their drug development status. Here is the list of possible groups:


A drug that has been approved in at least one jurisdiction, at some point in time. This does not mean the drug is currently approved or available, just that it has been approved and marketed at some point, somewhere. Different jurisdictions also have a different concept for "approval". For example drugs that are available over-the-counter in the U.S. may not be technically approved, whereas over-the-counter drugs in Canada are considered approved.

Vet Approved

A drug that has been approved in at least one jurisdiction, at some point in time for the treatment of animals.


A drug that is a pharmaceutical-grade and standardized nutrient (with confirmed or unconfirmed health benefits)


A drug that is scheduled in at least one jurisdiction, at some point in time.


A previously approved drug that has been withdrawn from the market in at least one jurisdiction, at some point in time. Note that because a drug can be approved in one jurisdiction, and withdrawn in another, it's possible for a drug to be in both groups. If a drug has been approved at some point in time, and then withdrawn, it would also be in both drug groups.


A drug that is in some phase of the drug approval process in at least one jurisdiction.


A compound that has been shown experimentally to bind specific proteins in mammals, bacteria, viruses, fungi, or parasites. This includes compounds that are Pre-Investigational New Drug Applications (Pre-IND, or Discovery Phase compounds).

Drug Binding

Each drug can have one or more targets, enzymes, transporters, and carriers associated with it. Here are the definitions for these different relationships:


A protein, macromolecule, nucleic acid, or small molecule to which a given drug binds, resulting in an alteration of the normal function of the bound molecule and a desirable therapeutic effect. Drug targets are most commonly proteins such as enzymes, ion channels, and receptors.


A protein which catalyzes chemical reactions involving the a given drug (substrate). Most drugs are metabolized by the Cytochrome P450 enzymes.


A membrane bound protein which shuttles ions, small molecules or macromolecules across membranes, into cells or out of cells.


A secreted protein which binds to drugs, carrying them to cell transporters, where they are moved into the cell. Drug carriers may be used in drug design to increase the effectiveness of drug delivery to the target sites of pharmacological actions.

Targets, Enzymes, Carriers, And Transporters may switch roles depending on the drug to which they bind. Some drugs specifically target transporters, and in this case a transporter can also be the target (for example: Procaine targeting the Sodium-dependent dopamine transporter).

Pharmacological Action

A target is marked with pharmacological action "yes" if the target is directly related to it's clinical mechanism of action. Targets that have a pharmacological action of "no" are considered off-targets, and may be related to side effects or drug interactions. "Unknown" indicates there is not enough evidence, or it has not yet been reviewed.

Guidelines for Cytochrome P-450 Interactions

CYP Substrate Sensitivity:

  • >5 fold change in AUC with index strong inhibitor = sensitive
  • 2 - 5 fold = moderate sensitivity
  • <2 fold = not sensitive

CYP Inhibitor Strength:

  • >5 fold change in AUC for index sensitive substrate = strong
  • 2 - 5 fold = moderate
  • 1.25 - 2 = weak
  • <1.25 = no significant inhibition

CYP Inducer Strength:

  • >80% reduction in AUC for index sensitive substrate = strong
  • 50-80% reduction = moderate
  • 20-50% reduction = weak
  • <20% = no significant inducement

Drug Field Documentation and Sources

Data sources indicate the source of the information present in each field. Data sources do not indicate that all sources were used for a particular field and drug. Individual drug reference information can be found in the "General References" section of each drug.

FieldDescriptionSourcesSmall Molecule?Biotech?
VersionEntry version
  • Automatic
Creation DateDate/time the entry was created
  • Automatic
Update DateDate/time the entry was last updated
  • Automatic
DrugBank ID (Primary Accession Number)Unique DrugBank accession number consisting of a 2 letter prefix (DB) and a 5 number suffix. This ID is used to access the drug entry via the URL. If an entry is deleted, it's DrugBank ID will not be reused.
  • Automatic
Secondary Accession NumberDrugBank release 1.0 accession number consisting of the 4 letter prefix and a 5 number suffix. Each Accession number is unique to the drug's generic name. The 4 letter suffix (APRD, EXPT, BIOD, NUTR) indicates the type of drug (APRD=approved small molecule drug, EXPT=experimental drug, BIOD=biotech drug, NUTR=nutraceutical or natural product).
  • Automatic
NameStandard name of drug as provided by drug manufactureryesyes
TypeCan be one of Small molecule or Biotech (see definition list in introduction).
  • Manual Search
GroupsCan be one or more of: Approved, Vet approved, Nutraceutical, Illicit, Withdrawn, Investigational, and Experimental. (see definition list in introduction)
  • Manual Search
DescriptionDescription of the drug describing general facts, composition and/or preparation.yesyes
KingdomOrganic or Inorganicyesyes
ClassesDrug classes form the major component of the classification system. Drugs with the same class are considered structurally similar.yesyes
Substructures and Functional GroupsAll substructures and functional groups calculated from the structure for the drug. This is a superset of the Classes.yesyes
SynonymsAlternate names of the drugyesyes
Brand NamesBrand names from different manufacturersyesyes
Brand MixturesBrand names and composition of mixtures that include the given drugyesyes
ManufacturersCompanies known to manufacturer the given drugyesyes
Packaging CompaniesCompanies which package and sell the given drugyesyes
PricesUnit cost drug prices in U.S. dollarsyesyes
PatentsDrug patents for the given drugyesyes
Chemical IUPAC NameIUPAC or standard chemical name for the drugyesno
Chemical FormulaChemical formula describing atomic or elemental compositionyesyes
Average Molecular WeightMolecular weight in g/mol, determined from molecular formula or sequenceyesyes
Monoisotopic Molecular WeightThe sum of the masses of the atoms in a molecule using the unbound, ground-state, rest mass of the principle (most abundant) isotope for each element instead of the isotopic average mass.yesno

For small molecule drugs, the 2D chemical structure including links to download and view the structure in various formats.

For biotech drugs, an image of the 3D structure and links to view the 3D structure in the structure viewer.

SMILESIsomeric SMILES string corresponding to drug structureyesno
InChIStandard InChI identifieryesno
InChI KeyStandard InChI keyyesno
CAS Registry NumberChemical Abstract Service identification numberyesyes
KEGG Drug IDKyoto Encyclopedia of Genes and Genomes drug identification number (if molecule is in KEGG)yesyes
KEGG Compound IDKyoto Encyclopedia of Genes and Genomes compound identification number (if molecule is in KEGG)yesyes
PubChem Compound IDNCBI's PubChem database compound identification numberyesyes
PubChem Substance IDNCBI's PubChem database subtance identification numberyesno
ChemSpider IDChemSpider identification numberyesno
BindingDB IDBindingDB identification numberyesyes
ChEBI IDEBI's Chemicals of Biological Interest identification number (if drug is in ChEBI)yesno
ChEMBL IDChEMBL identification numberyesno
Stitch IDStitch identification numberyesyes
Therapeutic Targets Database (TTD) IDTherapeutic Targets Database identification numberyesyes
PharmGKB IDPharmacogenomics Knowledge Base identification number (if molecule is in PharmGKB)yesyes
HET IDPDB identificatin number (if molecule is in PDB, ChemPDB or Ligand Depot)yesno
UniProt ID/NameUniProt database ID numbernoyes
GenBank IDGenBank database ID numbernoyes
Drug Product IDDrug Product Database Drug Identification Numberyesyes
RxList LinkLink to RxList entry for the given drug (if it exists)yesyes LinkLink to for the given drug (if it exists)yesyes
PDRhealth LinkLink to PDRhealth entry for the given drug (if it exists)yesyes
Wikipedia LinkLink to Wikipedia entry for the given drug (if it exists)yesyes
FDA LabelFood and Drug Administration approval label (if it exists)yesyes
Material Safety Data SheetMaterial Safety Data Sheet (MSDS) (if it exists)yesyes
Synthesis ReferenceReference or patent number to description of drug's synthesisyesyes
StatePhysical state (solid, liquid, gas)yesyes
Melting PointMelting point in degrees Celsiusyesyes
Boiling PointBoiling point in degrees Celsiusyesyes
Experimental Water SolubilityWater solubility in mg/mL or g/Lyesyes
Predicted Water SolubilityPredicted water solubility in mg/mLyesno
Experimental LogP/HydrophobicityWater/octanol partition coefficient (if small molecule) or hydrophobicity score (Gravy score) if protein/peptideyesyes
Predicted LogP/HydrophobicityPredicted water/octanol partition coefficientyesno
Predicted LogSPredicted LogS (water solubility)yesno
Experimental LogSExperimental LogS (water solubility)yesyes
Experimental Caco2 PermeabilityCaco-2 permeability coefficientsyesyes
pKa/Isoelectric PointDissociation constant (pKa) if small molecule, pH at which protein has no charge (if protein drug)yesyes
Mass SpectrumImage of EI Mass Spectrum of drug (if it exists)yesno
Experimental PDB EntriesPDB identification number if structure of drug exists in PDByesyes
CategoryTherapeutic category or general category of drug (anti-convulsant, antibacterial, etc.)yesyes
ATC CodesWHO drug classification system (ATC) identifiersyesyes
AHFS CodesAHFS Drug Information identifiersyesyes
IndicationDescription or common names of diseases that the drug is used to treatyesyes
PharmacodynamicsDescription of how the drug works at a clinical or physiological levelyesyes
Mechanism of ActionDescription of how the drug works or what it binds to at a molecular levelyesyes
AbsorptionDescription of how much of the drug or how readily the drug is taken up by the bodyyesyes
ToxicityLethal dose (LD50) values from test animals, description of side effects and toxic effects seen in humansyesyes
Protein BindingPercentage of the drug that is bound in plasma proteinsyesyes
MetabolismMechanism by which or organ location where the drug is neutralizedyesyes
Half LifeHalf life of drug in body, measured in hours or days
  • Manual Search
  • FDA
Route of EliminationRoute by which the drug is eliminated. Drugs are cleared primarily by the liver and kidneys.yesyes
Volume of DistributionThe apparent volume of distribution is the theoretical volume of fluid into which the total drug administered would have to be diluted to produce the concentration in plasmayesyes
ClearanceClearance is a descriptive term used to evaluate efficiency of drug removal from the bodyyesyes
Dosage FormsHow the drug is dispensed (tablets, capsules, solutions, etc.)yesyes
Drug InteractionsDrugs that are known to interact, interfere or cause adverse reactions when taken with this drugyesyes
Food InteractionsFoods that are known to interact, interfere or cause adverse reactions when taken with this drugyesyes
PathwaysDrug pathways in which the given drug is involvedyesyes
Organisms AffectedNames of organisms for which the drug is most effectiveyesyes
General ReferencesGeneral on-line reference to other details about the drugyesyes

Target / Enzyme / Transporter / Carrier Field Documentation

NameName of the protein or macromolecule (or other small molecule)
Gene NameGene name
SynonymsAlternate names (protein names, abbreviations, etc.)
Protein SequenceAmino acid sequence
Number of ResiduesNumber of amino acids in the protein sequence
  • Automatic
Molecular Weight (Daltons)Molecular weight given in Daltons or g/mol
  • Automatic
Theoretical pITheoretical isoelectric point
  • Automatic
GO ClassificationGene ontology classification including function, cellular process and location
General FunctionShort 3-4 word summary of the primary functions
Specific FunctionDetailed 30-40 word summary of the specific functions
PathwaysKey pathways or processes (from SMPD) that the given molecule is involved in
ReactionReaction(s) that the given molecule participates in
Pfam Domain FunctionNames and ID numbers of PFAM domains
SignalsLocation of signal peptide or other localization signals in the sequence
Transmembrane RegionsNumber and location of the transmembrane helices
EssentialityImportance or essentialness in terms of the organism's ability to survive without it
  • Manual Search
GenBank ID ProteinGenBank protein ID (if it exists)
UniProt ID/NameUniProt ID (if it exists)
PDB IDPDB ID (if it exists)
Cellular LocationLocation of the given protein or macromolecule inside or around the cell (cytoplasm, nucleus, membrane, etc.)
Gene SequenceDNA sequence (from cDNA) of the given molecule
GenBank ID GeneGenBank database gene identifier and link
GeneCards IDGeneCards database identifier and link
GenAtlas IDGenAtlas database identifier and link
HGNC IDHGNC database identifier and link
Chromosome LocationLocation of the molecule on any of the 23 human chromosomes (no location is given if the molecule is bacterial)
LocusMore detailed location of the chromosomal position of the gene
ReferencesPubmed references
Drug ReferencesSpecific references for the given drug association