Canadian DIN → RxNorm Crosswalk

Health Canada Drug Product Database, marketed human extract. Veterinary, disinfectant, and radiopharmaceutical classes are excluded.

What is a DIN?

A Drug Identification Number is an 8-digit number assigned by Health Canada to every drug product approved for sale in Canada. It identifies a specific manufacturer’s product by its active ingredients, strength, pharmaceutical form, and route of administration, and must appear on the product label. It is the primary key of Health Canada’s Drug Product Database (DPD).

The detail that trips up most integrations: a DIN does not encode package size. Unlike an NDC, whose final segment distinguishes a 30-count bottle from a 90-count bottle, one DIN covers every package size that manufacturer ships of that formulation. Package configurations live in a separate DPD table. That puts the DIN’s grain squarely between NDC and RXCUI — more specific than a clinical concept, less specific than a package.

DIN vs NDC vs RXCUI

There is no arithmetic conversion between a DIN and an NDC. They are issued by different regulators, for different markets, at different grains. The only route between them is a crosswalk through a shared clinical vocabulary.

For the US-only comparison, see RxNorm vs NDC and the RxNorm–NDC crosswalk.

Why the Mapping Is Harder Than a String Join

Both sides describe a drug by ingredient, strength, and dose form. Both express all three differently, and each mismatch is a distinct source of silently wrong mappings.

How Each DIN Resolves

Every row carries a match_method describing how it was resolved, so you can restrict an analysis to rule-verified lineage when the use case demands it. Four values, and the vocabulary is stable:

Sample Rows

Real rows from canada_drug_product. Note the two behaviours worth understanding: many DINs collapse to one RXCUI the same way many NDCs do, and brand and generic stay distinct — ELIQUIS resolves to a branded RxNorm concept while its generics resolve to the generic one.

Canada-Only Strengths: The Case Against Snapping to the Nearest Match

Some Canadian products have no RxNorm equivalent at their marketed strength even though RxNorm knows the drug perfectly well. Sertraline is the clearest case: Canada markets 25, 50, and 100 MG oral capsules, and RxNorm carries the clinical drug form sertraline Oral Capsule (RXCUI 373867) but no capsule product at those strengths. Eighteen DINs across ZOLOFT, APO-SERTRALINE, TEVA-SERTRALINE and others sit in that gap.

The tempting fix — map them to the nearest sertraline tablet — is exactly the failure mode that makes drug crosswalks dangerous. It produces a mapping that is wrong on dose form, and nothing downstream can tell. Instead these products resolve to a minted identifier alongside the RxNorm clinical drug form they legitimately belong to:

din                   02238282
brand_name            APO-SERTRALINE
strength_text         sertraline (sertraline hydrochloride) 100 MG
dose_form             CAPSULE
drug_id               NULL              -- no RxNorm product at this strength
clinical_drug_form_rxcui  373867        -- but the form is known
synthetic_drug_id     CA373867-ef40389887
synthetic_drug_name   sertraline 100 MG Oral Capsule [CA-only strength]
match_method          canada_only_strength

What Doesn’t Resolve, and Why

RxNorm covers the US market. Where Canada and the US diverge, no amount of matching effort produces a concept that does not exist. The unresolved population is dominated by four explainable groups:

Unresolved rows are not dropped. They keep every Health Canada attribute — brand, ingredients, strength, form, route, schedule, and ATC classification — so a Canada-only product is still analysable by therapeutic class even without an RXCUI.

Querying the Crosswalk

SELECT
    c.din,
    c.brand_name,
    c.strength_text,
    d.drug_name,
    d.ingredient,
    d.dose_form
FROM canada_drug_product c
JOIN drug_profile        d ON d.drug_id = c.drug_id
WHERE c.din = '02377233';

SELECT
    c.din,
    c.brand_name,
    c.schedule
FROM ndc_crosswalk        n
JOIN canada_drug_product  c ON c.drug_id = n.drug_id
WHERE n.ndc11 = '00093310905';

SELECT
    LEFT(c.atc_code, 3)   AS atc_class,
    COUNT(*)              AS dins,
    COUNT(DISTINCT c.drug_id) AS drug_concepts
FROM canada_drug_product c
WHERE c.is_prescription
  AND c.match_method = 'deterministic'
GROUP BY 1
ORDER BY dins DESC;

API endpoints

Full request and response shapes are in the API reference; the table and column definitions are on the schema reference.

Frequently Asked Questions