Skip to main content
Log in

Dose calculation in opioid rotation: electronic calculator vs. manual calculation

  • Research Article
  • Published:
International Journal of Clinical Pharmacy Aims and scope Submit manuscript


Objective To generate, validate and establish a web-based individualised opioid conversion calculator at the University Hospital Basel and to analyse its value and significance. Setting A 700-bed university hospital. Method Published data were screened by a Medline search using the keywords: opioid, rotation, switching, potency and dose ratio. Based on this data, the criteria for the conversion calculator were defined. A prospective process validation was performed prior to the approval. Five months after the introduction of the tool, an online survey was performed in order to evaluate its acceptance by users. In the last step, a manual calculation using a written table was compared with the calculator in a cross-over trial with 72 participants in order to assess the findings of the survey. Results The opioid conversion calculator could be generated for 24 combinations of 6 opioids for 5 different routes of administration. The validation of the calculator was performed successfully without discovering any major or critical defects. The proportion of correct answers increased from 68% using the table to 81% using the calculator (P < 0.001), the median time necessary to answer the ten questions was 8.9 min using the table and 4.8 min using the calculator. Conclusion A web-based opioid conversion calculator was planned, generated, validated and established at the hospital. Based on the results of the online survey and the results of our cross-over trial we conclude that the tool saves time compared to manual calculation and may contribute to patient safety by avoiding calculation errors. With this tool we contribute to the optimisation of processes in hospital and patient safety.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2

Similar content being viewed by others


  1. Gerbershagen HJ, Dagtekin O, Sabatowski R. Opioide—wann welche Applikationsform? [Opioids—when using which route of administration?] German. Arzneimitteltherapie. 2007;25(10):374–82.

    CAS  Google Scholar 

  2. Eychmüller S. Die Qual der Wahl bei der Therapie mit stark wirksamen Opioiden. Teil 1 von 2. [Therapy with opioids—to be spoilt for choice. Part 1 of 2] German. Prim Care. 2004;4(26):528–31.

    Google Scholar 

  3. Anderson R, Saiers JH, Abram S, Schlicht C. Accuracy in equianalgesic dosing: conversion dilemmas. J Pain Symptom Manage. 2001;21(5):397–406.

    Article  PubMed  CAS  Google Scholar 

  4. Aeschlimann A, Buettner UW, Desmeules JA, de Stoutz ND, Eychmüller S, Limacher F. Empfehlungen zur Opioidtherapie chronischer Schmerzen. Teil 2. [Recommendations for opioid therapy in chronic pain. Part 2] German. Schweiz Med Forum. 2005;5(44):1107–13.

    Google Scholar 

  5. Vissers KCP, Besse K, Hans G, Devulder J, Morlion B. Opioid rotation in the management of chronic pain: where is the evidence? Pain Pract. 2010;10(2):85–93.

    Article  PubMed  CAS  Google Scholar 

  6. Pereira J, Lawlor P, Vigano A, Dorgan M, Bruera E. Equianalgesic dose ratios for opioids: a critical review and proposals for long-term dosing. J Pain Symptom Manage. 2001;22(2):672–87.

    Article  PubMed  CAS  Google Scholar 

  7. Quinn TE. Converting opioid analgesics, Part II: review of equianalgesic conversion calculators. 3rd Revised Version. Pain Relief Connection [Internet]. 2007;6(2) [downloaded June 2008]. Available from URL:

  8. Eychmüller S. Die Qual der Wahl bei der Therapie mit stark wirksamen Opioiden. Teil 2 von 2. [Therapy with opioids—to be spoilt for choice. Part 2 of 2] German. Prim Care. 2004;4(27–28):561–4.

    Google Scholar 

  9. Äquivalenzdosen von Opioiden bei Langzeitanwendung. [Equianalgesic doses of opioids in long-term therapy] German. Version 3, 2010 [downloaded July 2010]. Available from URL:

  10. Note for guidance on process validation. The European Medicines Agency. CPMP/QWP/848/96 [Internet]. Sept 2001 [downloaded March 2010]. Available from URL:

  11. Bauer DF. Constructing confidence sets using rank statistics. J Am Stat Assoc. 1972;67:687–90.

    Article  Google Scholar 

  12. R Development Core Team. R: a language and environment for statistical computing. Vienna: R Foundation for statistical computing; 2008. ISBN 3-900051-07-0.

  13. Yan J, Fine J. Estimating equations for association structures. Stat Med. 2004;23:859–80.

    Article  PubMed  Google Scholar 

  14. Yan J. Geepack: yet another package for generalized estimating equations. R News 2002;2/3:12–14 [Internet]. Dec 2002 [downloaded July 2010]. Available from URL:

  15. Ripamonti C, Groff L, Brunelli C, Polastri D, Stavrakis A, De Conno F. Switching from morphine to oral methadone in treating cancer pain: what is the equianalgesic dose ratio? J Clin Oncol. 1998;16(10):3216–21.

    PubMed  CAS  Google Scholar 

  16. Mercadante S, Casuccio A, Fulfaro F, Groff L, Boffi R, Villari P, et al. Switching from morphine to methadone to improve analgesia and tolerability in cancer patients: a prospective study. J Clin Oncol. 2001;19(11):2898–904.

    PubMed  CAS  Google Scholar 

  17. Bach V, Kamp-Jensen M, Jensen NH, Eriksen J. Buprenorphine and sustained release morphine—effect and side-effects in chronic use. The Pain Clinic. 1991;4(2):87–93.

    Google Scholar 

  18. Benitez-Rosario MA, Feria M, Salinas-Martin A, Martinez-Castillo LP, Martin-Ortega JJ. Opioid switching from transdermal fentanyl to oral methadone in patients with cancer pain. Cancer. 2004;101(12):2866–73.

    Article  PubMed  CAS  Google Scholar 

  19. Santiago-Palma J, Khojainova N, Kornick C, Fischberg DJ, Primavera LH, Payne R, et al. Intravenous methadone in the management of chronic cancer pain. Cancer. 2001;92(7):1919–25.

    Article  PubMed  CAS  Google Scholar 

  20. Mercadante S, Ferrera P, Villari P, Casuccio A. Rapid switching between transdermal fentanyl and methadone in cancer patients. J Clin Oncol. 2005;23(22):5229–34.

    Article  PubMed  Google Scholar 

  21. Breitbart W, Chandler S, Eagel B, Ellison N, Enck RE, Lefkowitz M, et al. An alternative algorithm for dosing transdermal fentanyl for cancer-related pain. Oncology. 2000;14(5):695–705.

    PubMed  CAS  Google Scholar 

  22. Lawlor P, Turner K, Hanson J, Bruera E. Dose ratio between morphine and hydromorphone in patients with cancer pain: a retrospective study. Pain. 1997;72(1–2):79–85.

    Article  PubMed  CAS  Google Scholar 

  23. Hunt R, Fazekas B, Thorne D, Brooksbank M. A comparison of subcutaneous morphine and fentanyl in hospice cancer patients. J Pain Symptom Manage. 1999;18(2):111–9.

    Article  PubMed  CAS  Google Scholar 

  24. Budd K, Raffa RB (eds). Buprenorphine—the unique opioid analgesic. Stuttgart, New York: Thieme Verlag; 2005. ISBN 3-13-134211-0.

  25. Kalso E. Oxycodone. J Pain Symptom Manage. 2005;29(5S):S47–56.

    Article  PubMed  CAS  Google Scholar 

  26. Zhukovsky DS, Walsh D, Doona M. The relative potency between high dose oral oxycodone and intravenous morphine: a case illustration. J Pain Symptom Manage. 1999;18(1):53–5.

    Article  PubMed  CAS  Google Scholar 

  27. Plagge H, Bornand D, Ott N, Ruppen W, Vonderschmitt G, Gauggel M, Deuster S. Erstellung und Validierung eines Programms zur Berechnung von Opioid-Äquivalenzdosen. [Generation and validation of an opioid conversion calculator] (Poster) German. In: GSASA-Kongress, Lucerne, Switzerland 2008.

  28. Brant JM. Opioid equianalgesic conversion: the right dose. Clin J Oncol Nurs. 2001;5(4):163–5.

    PubMed  CAS  Google Scholar 

  29. Mercadante S. Opioid rotation for cancer pain: rationale and clinical aspects. Cancer. 1999;86(9):1856–66.

    Article  PubMed  CAS  Google Scholar 

  30. Galer BS, Coyle N, Pasternak GW, Portenoy RK. Individual variability in the response to different opioids: report of five cases. Pain. 1992;49(1):87–91.

    Article  PubMed  CAS  Google Scholar 

  31. Hanks GW, de Conno F, Cherny N, Hanna N, Kalso E, McQuay HJ, et al. Morphine and alternative opioids in cancer pain: the EAPC recommendations. Br J Cancer. 2001;84(5):587–93.

    Article  PubMed  CAS  Google Scholar 

  32. Pergolizzi J, Böger RH, Budd K, Dahan A, Erdine S, Hans G, et al. Opioids and the management of chronic severe pain in the elderly: consensus statement of an International Expert Panel with focus on the six clinically most often used World Health Organization Step III opioids (buprenorphine, fentanyl, hydromorphone, methadone, morphine, oxycodone). Pain Pract. 2008;8(4):287–313.

    Article  PubMed  Google Scholar 

Download references


We thank all physicians and pain nurses who took time to respond to the online questionnaire. We thank the students who have participated in the study and Christoph Bitter for his support during the study. Furthermore, we thank Allison Dwileski, B.S. (Scientific Secretary, Department of Anaesthesia and Intensive Care Medicine, University Hospital Basel, Basel, Switzerland), for providing editorial assistance.


We thank Janssen Cilag AG, Baar, Switzerland, for support by an unrestricted grant.

Conflicts of interest

The authors have no conflicts of interest to declare.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Herbert Plagge.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Plagge, H., Ruppen, W., Ott, N. et al. Dose calculation in opioid rotation: electronic calculator vs. manual calculation. Int J Clin Pharm 33, 25–32 (2011).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: