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Opioid (Narcotic) analgesic converter
Note: ALL METHADONE CALCULATIONS REMOVED -
Check out the new advanced version for methadone related conversions
Select a narcotic analgesic to convert
(Enter total daily dose in mg)
Incomplete cross-tolerance correction
: Reduction for incomplete cross tolerance:
(Usual range: 25 - 75% reduction)
Select a narcotic analgesic to convert
Based on your selections above, here is the result
Equivalent dose for opiate selected in Step 4 above:
Reduction for incomplete cross tolerance:
Chronic oral morphine equivalent dose is:
(Note: If morphine was chosen, the conversion factor used was for chronic dosing only. ) Ideally, we recommend our desktop program for much greater control over these conversions).
Review warnings or program notes if present below:
Before using this application, please review these important points:
Published equianalgesic ratios are considered
crude estimates at best
and therefore it is imperative that careful consideration is given to individualizing the dose of the selected opioid. Dosage titration of the new opioid should be completed slowly and with frequent monitoring.
Factors that must be addressed during the conversion process include
: Age of the patient or presence of coexisting conditions. Use additional caution with elderly patients (65 years and older), and in patients with liver, renal, or pulmonary disease.
Conversion ratios in many equianalgesic dosing tables do not apply to repeated doses of opioids.
The amount of residual drug in the patient's system must be accounted for
. Example: fentanyl will continue to be released from the skin 12 to 36 hours after removal of the patch. Residual effects from discontinued long-acting formulations should also be assessed before converting a patient to a new opioid.
The use of high but ineffective doses of a previous opioid may result in overestimation of the converted opioid.
Ideally, methadone conversions (especially patients who were previously receiving high doses of an opioid) should only be attempted in cooperation with a pain specialist or a specialist in palliative medicine.
Meperidine should be used for acute dosing only and not used for chronic pain management (meperidine has a short half-life and a toxic metabolite: normeperidine). Its use should also be avoided in patients with renal insufficiency, CHF, hepatic insufficiency, and the elderly because of the potential for toxicity due to accumulation of the metabolite normeperidine. Seizures, confusion, tremors, or mood alterations may be seen. In patients with normal renal function, total daily doses should not exceed 600mg/24hrs.
All calculations must be confirmed before use. The authors make no claims of the accuracy of the information contained herein; and these suggested doses are not a substitute for clinical judgment. Neither GlobalRPh Inc. nor any other party involved in the preparation of this program shall be liable for any special, consequential, or exemplary damages resulting in whole or part from any user's use of or reliance upon this material.PLEASE READ THE DISCLAIMER CAREFULLY BEFORE ACCESSING OR USING THIS SITE. BY ACCESSING OR USING THIS SITE, YOU AGREE TO BE BOUND BY THE TERMS AND CONDITIONS SET FORTH IN THE DISCLAIMER.
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Medical Calculators - A thru Z
Lab Values - A thru Z
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