Glossary
The identifiers, classification systems, and clinical and data terms you'll meet across pharmacopeia, defined in plain language. Definitions are reference-style, never clinical advice.
26 terms
RxCUI
RxNorm Concept Unique Identifier- A numeric identifier assigned by RxNorm (maintained by the U.S. National Library of Medicine) to a drug concept. RxCUIs let you link a drug across systems that all reference RxNorm.
UNII
Unique Ingredient Identifier- A non-proprietary, alphanumeric code from the FDA's Substance Registration System that uniquely identifies a substance based on its molecular structure or descriptive information.
ATC code
Anatomical Therapeutic Chemical classification- The WHO's hierarchical system that classifies drugs by the organ or system they act on and their therapeutic, pharmacological, and chemical properties. A code such as A10BA02 places metformin within the biguanide blood-glucose-lowering drugs.
EPC
Established Pharmacologic Class- An FDA-curated pharmacologic class assigned to a drug, describing its scientifically documented mechanism of action in a standardized phrase shown on labeling.
Mechanism of action
MoA- The specific biochemical interaction through which a drug produces its effect — for example, the molecular target it binds and what that binding does. In pharmacopeia, mechanism is a distinct, separately-sourced section of each drug record.
Indication
- A condition or use for which a drug is approved or recognized. In pharmacopeia, indications are reference facts drawn from labeling — not a recommendation that a given drug is appropriate for a given patient.
Contraindication
- A situation in which a drug should not be used because the risk clearly outweighs any benefit. Listed for reference only; clinical judgment always governs real use.
Boxed warning
Black box warning- The FDA's strongest labeling warning, used to highlight serious or life-threatening risks. It appears, when present, as a dedicated section of a drug's label record.
Adverse reaction
Adverse eventSide effect- An undesirable effect associated with use of a drug. pharmacopeia surfaces the adverse-reactions section of FDA labeling as structured text.
Drug interaction
- A change in a drug's effect caused by another drug, food, or condition taken together. pharmacopeia models known pairwise interactions with a severity grade, a mechanism, and a reference-style note.
SMILES
Simplified Molecular-Input Line-Entry System- A compact text notation that encodes a molecule's structure as a line of ASCII characters, so a chemical structure can be stored and transmitted as a string.
InChIKey
- A fixed-length, hashed version of the IUPAC International Chemical Identifier (InChI). Its uniformity makes it ideal as a database key and for web searches that resolve to a specific compound.
Active ingredient
- The component of a drug product that is pharmacologically active and responsible for its intended effect, as distinct from excipients (inactive ingredients).
Tanimoto similarity
- A coefficient between 0 and 1 measuring how similar two molecules are based on their structural fingerprints. pharmacopeia uses it to rank structurally similar drugs from PubChem 2D fingerprints.
Slug
- A stable, human-readable, lowercase-with-hyphens key (for example metformin) used to address every entity in pharmacopeia. Slugs never change and numeric database IDs are never exposed in the API.
Provenance
- The per-record audit trail attached to every fact in pharmacopeia: the canonical source URL, a source hash, when it was extracted, which extractor produced it, and a confidence score. It is how you verify any field and how the pipeline knows what to refresh.
Jurisdiction
- The regulatory region a record describes. v0 is US-FDA only; additional jurisdictions are added additively rather than by forking the dataset, because the same drug can be labeled differently in different regions.
AI-extracted
- A provenance label for content an LLM produced or rewrote. It is flagged with a visible badge so you read it critically and cross-check the linked source. Contrast with auto-sourced and curated content.
Definitions are simplified for a developer audience. For authoritative wording, follow each entity's cited source.