Definition and Purpose

Why Conversion is Needed

Risks of Incorrect Conversion

Opioid dose conversion is the process of calculating an equivalent dose when switching from one opioid medication to another. This ensures effective pain control while minimizing the risk of overdose or withdrawal.

Why is Opioid Conversion Important?

Different opioids have varying potencies and pharmacokinetics. Accurate conversion is essential for patient safety and optimal pain management.

Common Conversion Scenarios

Switching from oral morphine to transdermal fentanyl.

Rotating opioids due to side effects or tolerance.

Input Selection

Applying Cross-Tolerance Reduction

Interpreting Results

How to Use the Calculator

1. Select the current opioid and enter the total daily dose. 2. Choose the target opioid. 3. Enter the cross-tolerance reduction percentage (typically 25-50%). 4. Click Calculate to see the equivalent and adjusted doses.

Why Cross-Tolerance Matters

Cross-tolerance reduction accounts for incomplete tolerance between different opioids, reducing the risk of overdose.

Usage Examples

Reducing the calculated dose by 25% when switching opioids.

Using the calculator for both oral and IV opioid conversions.

Clinical Pain Management

Opioid Rotation

Palliative Care

Where is Opioid Conversion Used?

Opioid conversion is widely used in hospitals, pain clinics, and palliative care settings to optimize pain control and minimize side effects.

Opioid Rotation for Tolerance

When patients develop tolerance or experience side effects, switching to a different opioid can restore pain relief.

Clinical Examples

Hospice care opioid switching.

Managing chronic pain with opioid rotation.

Overestimating Cross-Tolerance

Ignoring Patient Factors

Using Outdated Conversion Charts

Avoiding Common Errors

Always use up-to-date, evidence-based conversion factors. Adjust for patient-specific factors such as age, organ function, and comorbidities.

Consult Clinical Guidelines

Never rely solely on calculators—consult clinical guidelines and pharmacists for complex cases.

Mistakes to Avoid

Not reducing the dose for cross-tolerance.

Using the same conversion for all patients.

Conversion Formula

Worked Example

Adjusting for Cross-Tolerance

The Conversion Formula

Equivalent Dose = (Current Dose × Current Opioid Factor) / Target Opioid Factor. Adjusted Dose = Equivalent Dose × (1 - Cross-Tolerance % / 100).

Example Calculation

If a patient is taking 60 mg oral morphine and is switching to oral oxycodone with a 25% cross-tolerance reduction: Equivalent Dose = (60 × 1) / 1.5 = 40 mg. Adjusted Dose = 40 × 0.75 = 30 mg.

Formula in Action

60 mg morphine (oral) → 30 mg oxycodone (oral) after 25% reduction.

40 mg oxycodone (oral) → 26.8 mg fentanyl (transdermal) after 33% reduction.