Features & Capabilities

Opioids by Chris Marcellino MD and Norris Vivatrat MD is an opioid analgesic dosage conversion calculator for use by trained medical professionals. The application supports conversion to and from opioids commonly prescribed and used in U.S. hospitals orally, parenterally, or transdermally, including morphine, codeine, hydromorphone, hydrocodone, fentanyl, methadone, oxycodone and oxymorphone. The application is intended to help and instruct in the process of conversion of opioid regimens.

• Native support for iPhone, iPad and iPod touch
• Multiple route support
• Multiple drug support
• Incomplete cross tolerance option
• Breakthrough dosing calculator
• Provides instructional details about each calculation
• Saves last calculation on exit
• Supports landscape and portrait modes
• Reference guide

By Professor EBM, the Internal Medicine Residency Teaching Resource for Evidence-Based Medicine: http://www.professorebm.com/, a resource of the Santa Clara Valley Medical Center.

While effort has been made to ensure that calculations are accurate and that conversion factors are in accordance with current accepted medical practices, use of this application is entirely at your own risk. This application should only be used by trained medical professionals and all results should be double checked by hand. Use of the app requires acceptance of the terms of use that are included with the application.

Please send support requests and feedback using the link in the About tab of the app, though as a free academic tool we only have limited resources to address new feature requests.

Opioid equipotency data is taken from CAPC conversion values except where noted (see the reference tab in the app.) CAPC values are as published in the Center to Advance Palliative Care Prescribing Opioids: A Reference Guide curriculum, which are adapted from McPherson ML. Demystifying Opioid Conversion Calculations: A Guide for Effective Dosing, 2nd ed. American Society of Health-System Pharmacists, Bethesda, Maryland, 2018. EPEC values are as published in EPEC-O Participants Handbook, 2005.

Chris Marcellino, MD — Mayo Clinic Norris Vivatrat, MD — UCSD Medical Center

Special thanks to Dr. Tom Mouser (EveryStep, Des Moines, IA) and Dr. David Rand (UVM Medical Center).

User Growth & Download Statistics

App Mature
By:
Chris Marcellino MD LLC
Rating:
4.30
(18)
Version:
3.0.3 Last updated: 2025-10-09
Version code:
878754694
Creation date:
2010-07-30
Compatible devices:
Size:
2.02MB
URLs:
Privacy policy
Full description:
See detailed description
Source:
Apple Apps Store
Data ingested on:
2026-06-06
Compare stats and ranking:

Contact the developer

Chrome-Stats does not own this Apple app. Please use these information below to contact the Apple app developer.
Developed by:
Chris Marcellino MD LLC
Apple Apps Store
https://apps.apple.com/us/app/opioids-dosage-conversion/id382383903

User Reviews

Opioids Dosage Conversion is a fast, handy tool that many clinicians rely on for quick equianalgesia calculations and teaching. It is praised for multi-opioid input, rapid results, and included references. However, reviews repeatedly call out gaps in drug coverage and dosing routes, accuracy issues (notably oxycodone-to-morphine), and usability drawbacks (cumbersome input and limited dosing options). Overall it’s a strong workflow aid when broadly applicable, but requires updates to expand coverage, improve accuracy, and enhance the user interface.
Pros
  • Fast and easy to use for quick MED calculations in busy clinical practice.
  • Valued in anesthesia and palliative care; widely used for teaching and training.
  • Supports entering multiple opioids and merges into a single consolidated conversion, reducing manual note-taking and potential errors.
  • Includes reference material and dosing guidance (e.g., methadone dosing) to verify conversions.
Cons
  • Incomplete drug coverage and routes (missing Tapentadol, oxymorphone, meperidine; no IV fentanyl; limited dosing options).
  • Accuracy concerns, especially oxycodone-to-morphine conversions (reported as incorrect); overall reliability questioned for some drugs.
  • Cumbersome input method (rollers instead of keypad) and usability issues; UI could be improved.
  • Limited dosing schedules (only q6h, q8h, and w24h) reduce flexibility for certain patients or settings.
Recent reviews
I use this app daily in my practice and regularly give it to learners. Great app!
by MD*****, 2025-09-02

Otherwise excellent app! Recommended throughout anesthesia and palliative departments
by Ni*****, 2023-07-14

Very cumbersome, and needs better user interface. Needs update.
by GA*****, 2022-07-26
View all user reviews ›

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