| Feature | WHO Drug Dictionary | MedDRA | RxNorm | | :--- | :--- | :--- | :--- | | | Drugs (medicinal products) | Medical conditions / adverse events | Clinical drugs (US-centric) | | Primary Use | Coding drug names & ATC classes | Coding adverse reactions & diagnoses | EHR interoperability in the US | | Global? | Yes (truly international) | Yes (but maintained by ICH) | No (only US drugs) |
Examples of popular digital drug dictionaries and online resources include: who drug dictionary