27-atc-ddd

name	27_ATC_DDD
description	Query the WHO ATC/DDD Classification System. Use whenever the user asks about ATC codes, drug classification hierarchy, Defined Daily Doses (DDD), or wants to look up drugs by ATC class or find the ATC code for a drug name.

ATC/DDD Query Skill

Look up ATC classification and DDD data for drugs. Auto-detects entity type:

Input Pattern	Detected As	Query Path
N02BA A10BA02 C09XX01	ATC code	local DDD lookup + RxNav member drugs
aspirin metformin	drug name	RxNav ATC classification + local DDD match

ATC code regex: ^[A-Z]\d{2}([A-Z]{1,2}\d{0,2})?$

API

Function	Input	Returns
load_local(path)	Excel path	list[dict] — cached ATC/DDD records
search(entity)	single string	dict with entity, entity_type, local_hits, api_hits
search_batch(entities)	list of strings	dict[str, dict] — keyed by entity
summarize(result)	search result dict	compact LLM-readable text
to_json(result)	search result dict	JSON string

All functions accept use_api=True|False to toggle RxNav queries (default: on).

Usage

See if __name__ == "__main__" block in 27_ATC_DDD.py for runnable examples:

from importlib import import_module
atc = import_module("27_ATC_DDD")

# Drug name → ATC classes
r = atc.search("aspirin")
print(atc.summarize(r))

# ATC code → member drugs + DDD
r = atc.search("N02BA")
print(atc.summarize(r))

# Batch
results = atc.search_batch(["metformin", "A10BA02", "C09XX01"])

# JSON for pipeline
print(atc.to_json(atc.search("sparsentan")))

Data

• Local file: ATC_DDD_new and alterations 2026_final.xlsx
• Columns: atc_code, atc_level_name, new_ddd, unit, adm_route, note
• Path: DATA_DIR / XLSX_PATH in 27_ATC_DDD.py
• Remote API: RxNav RxClass (rxnav.nlm.nih.gov/REST/rxclass/)
• Citation: WHOCC — WHO Collaborating Centre for Drug Statistics Methodology, ATC/DDD Index 2026. https://atcddd.fhi.no/atc_ddd_index/