April 21, 2023

Equianalgesia Opioid Calculator: JHH ApplicationsSuzanne A Nesbit, PharmD, CPEClinical Pharmacy Specialist, Pain Management

Department of Pharmacy

The Johns Hopkins Hospital

Patient Case

• 35 yo comes into the clinic complaining of persistent back pain. He has been taking Percocet (7.5mg oxycodone /324mg APAP) 2 tablets every 2-4 hours for his pain. He currently rates his pain 7/10.– Would you recommend any changes to his

regimen?• Long acting opioid + short acting for breakthrough

pain

Equianalgesia

• Different dose of two opioids that approximately provide the same pain relief

• convert route and drug

• morphine 10mg parenterally standard

• decrease dose by up to 50% in tolerant patient

Equianalgesic Conversion

• usually convert to morphine equivalents

• patient taking 18 Percocet (7.5mg/325mg) per day

• 18 X 7.5mg = 135 mg oxycodone

•

• 135 = 20 X = 202.5 mg oral morphine

• decrease dose for incomplete cross tolerance

30X

Opioid Rotation

• Unresponsiveness

• Unmanageable adverse effects

• Route of administration

• Potency

• Cost

Equianalgesic Chart

DrugParenteral

(mg) Oral (mg)Duration (hours)

Morphine 10 30 24

Hydromorphone 1.5 7.5 24

Oxycodone 20 24

Fentanyl 0.1 24

Methadone 5 10 68

Meperidine 75100 300 24

Oxymorphone 1 10 7-9

Current Equianalgesia Tables

• Single dose studies

• Broad guidelines

• Calculated dose reduced due to incomplete cross tolerance

• Clinical status of the patient considered

• Titrate and reassess

Equianalgesia Studies

• Single Dose– Usually acute pain ; opioid naïve patients

• Retrospective– Chart review of patients with opioid rotation

• Cross-over– Stable patients on an opioid; switched to

another to determine dose and analgesic effect

Dose Reduction

• Large interpatient variability in potencies to opioids

• Clinical status of patient: age, organ function, comorbidities, pain control

• Relative potencies for chronic dosing unknown• Cross-tolerance: incomplete

– start with 50%–75% of published equianalgesic dose– more if pain, less if adverse effects

• Methadone– start with 10%–25% of published equianalgesic dose

Challenging Conversions

• Fentanyl

• Methadone

• Oxycodone

• Hydromorphone

Johns Hopkins Opioid Conversion Software and Applications

• Floppy disc 1989• PDAs 2002

– Tungsten Palm Version– Windows CE Version

• Hopkins Opioid Program– Web-based version 2005

• www.hopweb.org• www.hopontheweb.org

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iPhone Application 2012

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Main Conversion Screen

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Drug and Dose Entry

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Final Output Screen

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