# /drugbank/drugs

`POST /api/drugbank/drugs`

Price: 5 credits

Get one DrugBank drug by its accession number. Returns the name, description, mechanism of action, primary indication, molecular formula and weight, first-approval countries and years, synonyms, development code names, brand names, development-status groups, modality, therapeutic categories and external cross-references to UNII, CAS, ChEMBL, ChEBI, PubChem, KEGG, RxNav and PharmGKB.

## How to use it

`cross_references` is the reason to call this endpoint on a drug you already know: it carries the UNII, CAS, ChEMBL, ChEBI, PubChem, KEGG, RxNav and PharmGKB identifiers, which is how a DrugBank record is joined to chemistry and drug-label sources. Everything DrugBank is known for beyond the identity card is behind a paid account and is returned by no endpoint here — targets, enzymes and transporters, drug-drug interactions, pharmacokinetics, pathways, dosage forms, SMILES and InChI, and protein sequences. Content depends on development status: an experimental compound usually carries only a formula and a description, while `mechanism_of_action` and `primary_indication` are populated mostly on approved and biologic entries, and for those two an empty value is DrugBank's own silence rather than a parse failure. `categories` is not: it is the chip row the drug page prints, a different list from the Categories column drugbank/drugs/search returns for the same drug — the two diverge in both directions and the drug page frequently prints no chips at all, so an empty `categories` here does not mean DrugBank files the drug under no class; read the search row's `categories` and `category_ids` alongside it. `id` is the only accepted input — a drug name does not resolve here and there is no name lookup anywhere on this platform, so reach a drug by walking drugbank/drugs/search or by the id from drugbank/categories.

## Parameters

- `access-token` (string, required)

## Request body

- `timeout` (integer) — Max scrapping execution timeout (in seconds) (default: 300; min: 20; max: 1500)
- `drug_id` (string, required) — DrugBank accession number. Case-insensitive, and a go.drugbank.com drug URL is accepted in place of the id (examples: "DB00945", "db00316", "https://go.drugbank.com/drugs/DB00331"; minLength: 1)

## Response

### 200 — Successful Response

- `@type` (string) (default: "DrugbankDrug")
- `id` (string, required)
- `name` (string) (default: "")
- `web_url` (string) (default: "")
- `description` (string) (default: "")
- `mechanism_of_action` (string) (default: "")
- `primary_indication` (string) (default: "")
- `molecular_formula` (string) (default: "")
- `molecular_weight` (number, nullable)
- `molecular_weight_unit` (string) (default: "")
- `groups` (array) (default: [])
- `modality` (string) (default: "")
- `approvals` (array) (default: [])
  - `@type` (string) (default: "DrugbankApproval")
  - `country` (string) (default: "")
  - `year` (integer, nullable)
- `synonyms` (array) (default: [])
- `code_names` (array) (default: [])
- `brand_names` (array) (default: [])
- `categories` (array) (default: [])
  - `@type` (string) (default: "DrugbankDrugCategory")
  - `id` (string) (default: "")
  - `name` (string) (default: "")
  - `web_url` (string) (default: "")
- `cross_references` (array) (default: [])
  - `@type` (string) (default: "DrugbankCrossReference")
  - `source` (string) (default: "")
  - `identifier` (string) (default: "")
  - `url` (string) (default: "")

## Errors

### 422 — Validation Error

drug_id was not a DrugBank accession number — DB followed by exactly five digits

What to do: Check the fields against this schema. A URN with the wrong prefix is the most common cause.

- `detail` (array)
  - `loc` (array, required)
  - `msg` (string, required)
  - `type` (string, required)
  - `input` (any)
  - `ctx` (object)

### 408

The request ran past its time limit

What to do: Raise `timeout` in the request body, up to the maximum this endpoint documents. Lowering `count` or turning off the `with_*` flags also helps, because less work finishes sooner.

### 412

No drug with that accession number. Ids look like DB00945; a salt or category id does not resolve

What to do: Retrying will not help: either the entity does not exist, or the input points at a different one.

### 429

Too many requests: a rate limit or a usage window is exhausted

What to do: When the response carries an X-Retry-After header, wait that many seconds and retry: the same number is in the body as `detail.retry_after`, and the limit clears once that window passes. The message in the body names the limit that was hit.

### 500

Something broke on our side

What to do: Retrying will not help. If it keeps happening, send us the X-Request-ID from the response headers.

### 529

Rate limit reached, or the endpoint is overloaded

What to do: Wait at least 30 seconds, then retry.

## Response envelope

Success: Array of objects (may be empty if no results)

Error: Error may coexist with partial results if it occurs mid-execution. Check X-Error header and status code.

Every response carries these headers:

- `X-Error` — Error message text (present only on error)
- `X-Request-ID` — Unique request identifier
- `X-Execution-Time` — Execution time in seconds
- `X-Result-Count` — How many records the body carries. 0 means an empty result, which is a normal answer and not by itself an error. A non-zero count can come back together with X-Error when the failure happened partway through — read this header and X-Error independently.
- `X-Total-Available-Results` — How many records exist for this query, when the endpoint can say. On a `dry_run` request this is the answer and the body is empty. It saturates: the endpoint's documented maximum means 'at least that many', any smaller number is exact.
- `X-Warning` — Present when the request body carried keys this endpoint does not document. They were ignored, so any filter you meant to apply through them did not apply. Check the spelling against this schema and retry.
- `X-Retry-After` — Seconds to wait before retrying. Present only on 429.