Opiate Conversion Calculator

Why Use

Helps avoid uncontrolled pain or respiratory depression and hypotension when converting between opiates.

When to Use

Patients taking opiates, for whom conversion between type and/or route of administration is indicated.

Formula

Pearls / Pitfalls

Be aware that there are no universally accepted standard methods for opioid conversion, and conversion factors may differ across various references. Opiate conversion calculations should always be taken as a guide and are not absolute guaranteed equivalents between different medications and dosage forms. Patients on a particular opiate for an extended amount of time will often develop tolerance, and a lower conversion dose of 33-50% is recommended unless the patient is under close monitoring.

Advice

Opiates vary widely in terms of potency. Always double check doses and units. Conversion factors may differ across various sources. This tool utilizes the conversion factors published in McPherson (2010) . Accordingly, these results are approximate and should be viewed as general reference points that must be applied in conjunction with clinical judgment and expertise. Decreasing the dose of the new opiate by 33-50% is strongly recommended unless the patient is in severe uncontrolled pain on the current regimen. Consultation with a pain management physician or pharmacist is recommended if converting to and from multiple opiates or from fentaNYL.