drugfyi

Python API client for drug interaction and pharmacology data. Check drug-drug interactions, look up side effect profiles, explore pharmacokinetic properties (absorption, metabolism, half-life), and query mechanism of action — all from DrugFYI, a drug reference platform built for healthcare developers and pharmacists.

DrugFYI aggregates pharmacological data including interaction severity ratings, cytochrome P450 enzyme pathways, therapeutic drug classes, contraindications, and adverse reaction frequencies — providing structured access to critical medication safety information.

Check drug interactions at drugfyi.com — search drugs, explore interactions, and browse drug classes.

Table of Contents

• Install
• Quick Start
• What You Can Do
  • Drug-Drug Interactions
  • Side Effect Profiles
  • Pharmacokinetics
  • Drug Classifications
• Command-Line Interface
• MCP Server (Claude, Cursor, Windsurf)
• REST API Client
• API Reference
• Learn More About Drugs
• Also Available
• Health FYI Family
• License

Install

pip install drugfyi                # Core (zero deps)
pip install "drugfyi[cli]"         # + Command-line interface
pip install "drugfyi[mcp]"         # + MCP server for AI assistants
pip install "drugfyi[api]"         # + HTTP client for drugfyi.com API
pip install "drugfyi[all]"         # Everything

Quick Start

from drugfyi.api import DrugFYI

with DrugFYI() as api:
    # Check interaction between two drugs
    interaction = api.get_interaction("warfarin", "aspirin")
    print(interaction["severity"])       # Major
    print(interaction["description"])    # Increased bleeding risk

    # Get complete drug profile
    drug = api.get_drug("metformin")
    print(drug["class"])                 # Biguanides
    print(drug["mechanism"])             # Decreases hepatic glucose production

    # Search across all drugs
    results = api.search("statin")

What You Can Do

Drug-Drug Interactions

Drug interactions occur when one medication affects the activity of another, potentially causing therapeutic failure or adverse effects. Interactions are classified by severity (major, moderate, minor) and mechanism (pharmacokinetic vs pharmacodynamic).

Severity	Clinical Significance	Action Required
Major	Life-threatening or permanent damage	Avoid combination
Moderate	May require therapy modification	Monitor closely
Minor	Minimal clinical significance	Awareness only
Contraindicated	Absolutely avoid	Never co-prescribe

from drugfyi.api import DrugFYI

with DrugFYI() as api:
    # Check specific drug pair interaction
    interaction = api.get_interaction("warfarin", "ibuprofen")
    print(interaction["severity"])       # Major
    print(interaction["mechanism"])      # CYP2C9 inhibition + antiplatelet effect
    print(interaction["recommendation"])

    # Get all interactions for a drug
    interactions = api.list_interactions("warfarin")
    major = [i for i in interactions if i["severity"] == "Major"]
    print(f"Warfarin has {len(major)} major interactions")

Learn more: Drug Interactions · Glossary

Side Effect Profiles

Every medication carries a side effect profile derived from clinical trials and post-marketing surveillance. Side effects are categorized by frequency (very common >10%, common 1-10%, uncommon 0.1-1%, rare <0.1%) and organ system affected.

from drugfyi.api import DrugFYI

with DrugFYI() as api:
    # Get side effect profile
    drug = api.get_drug("metoprolol")
    for effect in drug["side_effects"]:
        print(f"{effect['name']}: {effect['frequency']}")
        # Fatigue: Very Common (>10%)
        # Dizziness: Common (1-10%)
        # Bradycardia: Common (1-10%)

Learn more: Drug Side Effects · Guides

Pharmacokinetics

Pharmacokinetics — how the body processes a drug — follows four phases: Absorption (A), Distribution (D), Metabolism (M), and Elimination (E). Understanding ADME properties is critical for dosing, timing, and predicting interactions via shared metabolic pathways.

Parameter	Meaning	Clinical Relevance
Bioavailability	% reaching systemic circulation	Oral vs IV dosing
Half-life	Time for 50% elimination	Dosing frequency
CYP enzymes	Metabolic pathway	Interaction prediction
Protein binding	% bound to albumin	Drug displacement interactions

from drugfyi.api import DrugFYI

with DrugFYI() as api:
    # Pharmacokinetic properties
    drug = api.get_drug("atorvastatin")
    pk = drug["pharmacokinetics"]
    print(pk["bioavailability"])      # 14%
    print(pk["half_life"])            # 14 hours
    print(pk["metabolism"])           # CYP3A4
    print(pk["protein_binding"])      # >98%

Learn more: Pharmacokinetics · Glossary

Drug Classifications

Drugs are organized by therapeutic class (what they treat), pharmacological class (how they work), and chemical class (molecular structure). The ATC (Anatomical Therapeutic Chemical) classification system provides a standardized 5-level hierarchy.

Level	ATC Code	Meaning	Example
1st	C	Cardiovascular system	—
2nd	C10	Lipid modifying agents	—
3rd	C10A	Cholesterol/triglyceride reducers	—
4th	C10AA	HMG-CoA reductase inhibitors	Statins
5th	C10AA05	Specific chemical	Atorvastatin

from drugfyi.api import DrugFYI

with DrugFYI() as api:
    # Browse drug classes
    classes = api.list_classes()
    for cls in classes[:5]:
        print(f"{cls['name']}: {cls['drug_count']} drugs")

    # Get all drugs in a class
    statins = api.get_class("statins")
    for drug in statins["drugs"]:
        print(drug["name"])

Learn more: Drug Classes · API Documentation

Command-Line Interface

pip install "drugfyi[cli]"

drugfyi drug metformin                          # Drug details
drugfyi interaction warfarin aspirin             # Check interaction
drugfyi interactions warfarin                    # All interactions for a drug
drugfyi search "ACE inhibitor"                   # Search drugs
drugfyi classes                                  # List drug classes

MCP Server (Claude, Cursor, Windsurf)

pip install "drugfyi[mcp]"

{
    "mcpServers": {
        "drugfyi": {
            "command": "uvx",
            "args": ["--from", "drugfyi[mcp]", "python", "-m", "drugfyi.mcp_server"]
        }
    }
}

REST API Client

from drugfyi.api import DrugFYI

with DrugFYI() as api:
    drug = api.get_drug("metformin")                    # GET /api/v1/drugs/metformin/
    interaction = api.get_interaction("warfarin", "aspirin")  # GET /api/v1/interactions/warfarin/aspirin/
    classes = api.list_classes()                         # GET /api/v1/classes/
    results = api.search("beta blocker")                # GET /api/v1/search/?q=beta+blocker

Example

curl -s "https://drugfyi.com/api/v1/drugs/metformin/"

{
    "slug": "metformin",
    "generic_name": "Metformin",
    "class": "Biguanides",
    "mechanism": "Decreases hepatic glucose production",
    "route": "Oral"
}

Full API documentation at drugfyi.com/developers/.

API Reference

Function	Description
api.get_drug(slug)	Complete drug profile
api.list_drugs()	List all drugs
api.get_interaction(drug1, drug2)	Check specific interaction
api.list_interactions(drug)	All interactions for a drug
api.list_classes()	All therapeutic drug classes
api.get_class(slug)	Drug class details with member drugs
api.search(query)	Search across drugs and classes

Learn More About Drugs

• Browse: Drug Database · Interactions · Drug Classes
• Guides: Pharmacology Guides · Glossary
• API: REST API Docs · OpenAPI Spec

Also Available

Platform	Install	Link
npm	npm install drugfyi	npm
MCP	uvx --from "drugfyi[mcp]" python -m drugfyi.mcp_server	Config

Health FYI Family

Part of the FYIPedia open-source developer tools ecosystem — human body, medicine, and nutrition.

Package	PyPI	npm	Description
anatomyfyi	PyPI	npm	14,692 anatomical structures, body systems, organs — anatomyfyi.com
pillfyi	PyPI	npm	Pill identification, FDA drug database — pillfyi.com
drugfyi	PyPI	npm	Drug interactions, pharmacology, side effects — drugfyi.com
nutrifyi	PyPI	npm	Nutrition data, food composition, dietary analysis — nutrifyi.com

License

MIT