Drug Interaction Safety Checker

Real-time drug-drug interaction detection with five-level severity classification (A/B/C/D/X), modeled after the Lexicomp grading system. This skill checks for drug-disease contraindications, drug-dose range violations, and drug-food interactions by referencing FDA adverse event databases and peer-reviewed clinical pharmacology sources.

Quick Install

npx skills add Open-Medica/open-medical-skills --skill drug-interaction-checker

What It Does

• Severity classification: Grades every interaction on the A/B/C/D/X scale, where A indicates no known interaction and X indicates a contraindicated combination that should be avoided entirely
• Multi-axis screening: Evaluates drug-drug, drug-disease, drug-food, and drug-dose interactions in a single pass rather than checking each axis independently
• Duplicate therapy detection: Identifies overlapping pharmacologic classes when two or more agents share the same mechanism of action
• Renal and hepatic adjustment alerts: Flags medications that require dose modifications based on organ function, including CrCl-based thresholds and Child-Pugh scoring
• Structured output: Returns interaction results in a machine-readable format that downstream agents or clinical dashboards can consume directly

Clinical Use Cases

• Polypharmacy review: A hospitalist adding a new antibiotic to a patient already on eight chronic medications can run the full regimen through the checker before placing the order
• Transitions of care: During discharge reconciliation, the skill screens the combined inpatient and outpatient medication lists for conflicts introduced during the hospital stay
• Warfarin management: Catches CYP2C9 and CYP3A4 interactions with newly prescribed drugs that may potentiate or diminish anticoagulant effect
• Geriatric medication review: Flags Beers Criteria medications and high-risk combinations common in elderly patients taking five or more concurrent drugs

Safety & Evidence

• Safety Classification: Safe — The skill provides information and alerts only; it does not modify orders, prescriptions, or patient records. All interaction data is derived from published references and regulatory databases.
• Evidence Level: High — Interaction severity grading follows established frameworks (Lexicomp A-X scale) backed by FDA labeling, DailyMed, and published pharmacokinetic studies.

Example Usage

Checking a two-drug pair:

Check interaction between warfarin and fluconazole

Result: Severity X (Avoid Combination). Fluconazole is a potent CYP2C9 inhibitor that significantly increases warfarin plasma concentrations. Case reports document INR values exceeding 10 with concurrent use. If unavoidable, reduce warfarin dose by 25-50% and monitor INR every 2-3 days.

Screening a full medication list:

Screen the following regimen for interactions:
- Lisinopril 20mg daily
- Metformin 1000mg BID
- Atorvastatin 40mg daily
- Amlodipine 5mg daily
- Ibuprofen 600mg TID

Result: Severity C (Monitor Therapy) between lisinopril and ibuprofen: NSAIDs may reduce antihypertensive efficacy and increase risk of acute kidney injury, particularly in volume-depleted patients. Consider acetaminophen as an alternative analgesic.

Technical Details

• Category: Treatment
• Author: OMS Contributors
• License: MIT
• Version: 1.0.0
• Specialty: Pharmacy, Clinical Pharmacology

References

• Lexicomp Drug Interaction Classification System (Wolters Kluwer)
• FDA Adverse Event Reporting System (FAERS) database
• Hansten PD, Horn JR. Drug Interactions Analysis and Management. Wolters Kluwer, updated quarterly.
• American Geriatrics Society 2023 Updated Beers Criteria for Potentially Inappropriate Medication Use in Older Adults. J Am Geriatr Soc. 2023;71(7):2052-2081.
• DailyMed drug labeling repository (National Library of Medicine)

This skill is part of Open Medical Skills, a curated marketplace of medical AI skills maintained by physicians for physicians and the healthcare industry.