Opioids Dosage Conversion vs WarfarinGuide
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Opioids Dosage Conversion
This app is a calculator for trained medical professionals to convert opioid analgesic dosages. It supports various common opioids and administration routes, offering features like breakthrough dosing and cross-tolerance calculations.
- Opioid dosage conversion
- Multiple drug support
- Multiple route support
- Breakthrough dosing calculator
- Incomplete cross tolerance option
- Instructional details
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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).
WarfarinGuide
This app provides evidence-based resources for anticoagulation management with Warfarin. It includes guidelines on indications, INR targets, and treatment duration, along with protocols for dose adjustment and initiation. It also offers guidance for peri-operative Warfarin management.
- Warfarin dose adjustment protocols
- Warfarin initiation protocols
- INR target guidelines
- Peri-operative Warfarin management
- ACCP guideline references
- Point of care guides
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Warfarin Guide offers three resources essential for systematic and careful evidence-based anticoagulation with Warfarin. First it reviews recommendations on indications, INR targets, and treatment duration from the American College of Chest Physicians 8th Edition guidelines on Antithrombotic and Thrombolytic Therapy from 2008, updated for the 2012 guideline. Second it offers a protocol for Warfarin dose adjustment depending upon INR result. And third is a discussion of protocols for the initiation of Warfarin. These resources come from point of care guides on these topics in the family medicine literature as well as the 2012 ACCP guideline. The app also offers guidance for management of peri-operative Warfarin by directing the user to oexcellent comprehensive resources for managing all anticoagulants and antiplatelet agents around surgery. The app addresses such common questions as: •which artificial heart valves require that higher level of anticoagulation? •how do I respond to an INR of 7.4? •this pt needs Warfarin, how do I get it started? •I'm adjusting the total weekly warfarin dose down by 5%, when should I recheck the INR? •when do I give Vitamin K to reverse Warfarin anticoagulation and at what dose?? This app is written and intended for practicing clinicians involved in Warfarin anticoagulation such as internists, cardiologists, family physicians, nurses, pharmacists, PA's and NP's; for resident physician trainees; and for medical students. As an educator and clinician, I am interested in feedback and I would be grateful for guidance on improving the tool.
Screenshots
Verdict
The clearest difference is rating: Opioids Dosage Conversion at 4.3 against WarfarinGuide's 3.8. Opioids Dosage Conversion also leads on update cadence (every 4 months vs every 11 months) and ratings volume (18 vs 5). WarfarinGuide's advantage is review sentiment (90% vs 78%) and iOS requirement (13.0 vs 15.6). On price, ads, in-app purchases and monetization model there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
Opioids Dosage Conversion holds the better App Store score, 4.3 against 3.8. Both are backed by a comparable volume of ratings — 18 and 5 respectively. Written reviews complicate that: 78% of Opioids Dosage Conversion's written reviews are positive against 90% of WarfarinGuide's, so the app with the better star average is not the one people write more warmly about.
Opioids Dosage Conversion ships an update every 4 months, WarfarinGuide every 11 months. The most recent releases landed on September 17, 2026 and July 25, 2026 respectively.
| Parameter | Opioids Dosage Conversion | WarfarinGuide |
|---|---|---|
| Price | Free | Free |
| Rating | 4.3 (18 ratings) — better | 3.8 (5 ratings) |
| Positive reviews | 77.8% of reviews | 90.0% of reviews — better |
| Number of ratings | 18 — better | 5 |
| Update frequency | Every 4 months — better | Every 11 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod — better | iPhone, iPod |
| Requires iOS | 15.6 | 13.0 — better |
| Further details — not scored | ||
| Size | 2 MB | 1 MB |
| Age rating | 17+ | 17+ |
| Developer | Chris Marcellino MD LLC | Joshua D. steinberg |
Customer experience
Opioids Dosage Conversion
WarfarinGuide
In-app purchases
Opioids Dosage Conversion
No in-app purchases
WarfarinGuide
No in-app purchases
Questions
Is Opioids Dosage Conversion free?
Is WarfarinGuide free?
Which has better reviews, Opioids Dosage Conversion or WarfarinGuide?
Do Opioids Dosage Conversion or WarfarinGuide have ads?
Which is updated more often, Opioids Dosage Conversion or WarfarinGuide?
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