Enter Pair Details
Use this form to screen a medicine pair with weighted interaction domains and patient modifiers. The score helps organize review priorities and does not replace professional judgment.
Example Data Table
These examples show how weighted flags can change the screening score. They are generic review scenarios, not prescribing advice.
| Scenario | Key Flags | Total Risk | Compatibility Index | Interpretation |
|---|---|---|---|---|
| Low-Concern Pair | Minor class overlap only | 8 | 92 | Generally compatible with routine verification. |
| Sedation Watch Pair | CNS moderate + alcohol occasional | 14 | 86 | Caution with impairment and falls review. |
| Monitoring-Sensitive Pair | CYP high + narrow index + monitoring gap | 37 | 63 | Clinical review advised before use. |
| High-Alert Pair | Duplicate ingredient + QT high + renal high | 70 | 30 | High alert requiring urgent professional review. |
Formula Used
This checker uses a weighted screening model rather than a single pharmacology equation. Each selected interaction domain adds points based on its review importance.
Weighted Risk Score = Sum of all selected domain points
Total Risk Score = Minimum of 100 and Weighted Risk Score
Compatibility Index = Maximum of 0 and (100 − Total Risk Score)
Higher risk points reduce the compatibility index. Duplicate ingredient, major QT concern, strong serotonin load, severe organ-function issues, and missing monitoring carry heavier penalties because they often warrant faster review.
| Domain | Typical Weight Range | Reason |
|---|---|---|
| Duplicate ingredient | 35 | Possible duplication can create immediate avoidable harm. |
| QT, serotonin, bleeding, CNS | 5 to 20 | These reflect common high-priority interaction themes. |
| Renal or hepatic burden | 4 to 15 | Reduced clearance can increase exposure and toxicity. |
| Patient modifiers | 4 to 12 | Age, pregnancy, alcohol, herbs, and monitoring change context. |
How to Use This Calculator
- Enter both medicine names and optional dose notes.
- Select the best-fit flags for interaction domains and patient modifiers.
- Submit the form to generate the compatibility index above the form.
- Review the risk breakdown table and Plotly graph for major contributors.
- Download CSV or PDF if you want a portable summary.
- Use the output as a structured review aid, then confirm with a clinician or pharmacist.
Frequently Asked Questions
1) Does this tool identify real drug interactions automatically?
No. It does not connect to a live medication database. It scores the risk factors you manually select and helps organize review priorities.
2) What does the compatibility index mean?
It is a screening score from 0 to 100. Higher values indicate fewer selected concern flags. Lower values indicate more review pressure.
3) Why can two low-risk selections still matter clinically?
Interaction risk is cumulative. Several mild concerns can still become important when age, organ function, alcohol use, or poor monitoring are present.
4) Why is duplicate ingredient weighted heavily?
Therapeutic duplication can raise exposure without added benefit. It often deserves immediate verification before the pair is used together.
5) Can I use this result to start, stop, or combine medicines?
No. This page is educational. Never change treatment based only on this result. Confirm every decision with a qualified clinician or pharmacist.
6) What if I do not know the interaction domain values?
Leave unknown items at the lowest reasonable setting and treat the result cautiously. Unknown factors reduce confidence in the screening score.
7) Are dose entries used directly in the formula?
Not in this version. Dose fields are captured for documentation and export, while the score is driven by the selected concern flags.
8) When should I escalate a pair for professional review?
Escalate when the index is low, multiple major domains are triggered, symptoms exist, or monitoring is missing. Urgent review is wise for high-alert results.