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Calcimator

Polypharmacy Risk Score Calculator

Drug interaction risk from medication count, high-risk classes, renal function, and anticholinergic burden.

Inputs

years
mL/min

Results

Interaction risk score

27.4

Polypharmacy level2
Estimated potential interactions0.3
ADE risk category (1-5)2
Fall risk from medications13
Deprescribing opportunity10
How to Use This Calculator
  1. Enter the total Number of Medications the patient takes daily.
  2. Enter the number of medications with high fall risk, anticholinergic burden, and renal dose concerns.
  3. Review the Polypharmacy Risk Score and overall medication burden classification.
  4. Check flagged medication categories to prioritize a comprehensive medication review.
  5. Use the score to initiate deprescribing discussions and pharmacist consultation.

How the result changes with Total medications

Total medicationsInteraction risk score
38.8
11100
20100
27100

What each input means

Total medications
Total number of scheduled and PRN medications the patient takes.
High-risk medications
Number of high-risk drugs (anticoagulants, opioids, insulin, digoxin, lithium, etc.).
Patient age
Patient age in years. Risk increases sharply after age 75 and 85.
eGFR
Estimated glomerular filtration rate. Lower eGFR means reduced drug clearance.
Anticholinergic burden score
Sum of anticholinergic burden from all medications (0-10 scale).
PRN medications
Number of as-needed (PRN) medications — candidates for deprescribing review.

What each result means

Interaction risk score
Combined drug interaction risk (0-100). Higher = greater probability of adverse interactions.
Polypharmacy level
1 = No polypharmacy (<5 meds), 2 = Polypharmacy (5-9), 3 = Hyperpolypharmacy (10+).
Estimated potential interactions
Approximate number of clinically significant drug-drug interactions expected.
ADE risk category (1-5)
Adverse drug event risk: 1 = very low, 5 = very high.
Fall risk from medications
Medication-related fall risk score (0-100).
Deprescribing opportunity
Score indicating potential benefit from medication review and deprescribing (0-100).

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Total medications = 5, High-risk medications = 1, Patient age = 75, eGFR = 60 = 6 input(s) provided
  2. Calculate Interaction risk score
    Interaction risk score
    27.4 = 27.4
  3. Calculate Polypharmacy level
    2 = 2
  4. Calculate Estimated potential interactions
    Estimated potential interactions
    0.3 = 0.3

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