The rational use of cannabis-based medicines

High-quality medicines are one of the health sector’s greatest tools. They are used to treat or prevent disease and to promote health.

The rational use of medicines requires that ‘patients receive medications appropriate to their clinical needs, in doses that meet their own individual requirements, for an adequate period of time, and at the lowest cost to them and their community.’

The rational use of medicines, WHO 2020

Cannabis-based medicines are cannabis-derived, with a defined and standard cannabinoid content. They are typically administered by inhalation, by the oromucosal or the oral route. These medicines are still very new to most health professionals.

The rational use of cannabis-based medicines requires health professionals consider their clinical utility, with patient safety in mind.

This clinical primer seeks to share knowledge of good prescribing, dispensing and administration practices. It aims to improve the health professions ability to discuss the benefits and risks of cannabis-based medicines with their patients, family or carers, and to make clinical decisions that improve patient safety and treatment outcomes.

How to use the Clinical Primer

The clinical primer on cannabis has nine modules with specific learning objectives to guide your progress. Navigating the modules is straightforward.

The Clinical modules are a fully referenced guidance text, providing an in-depth understanding. And you can test your knowledge with the clinical quiz – did you miss something?

The Peer Insights module shows how various experienced peers across the globe prescribe, dispense, and administer cannabis-based medicines through a series of insightful easy-to-read clinical questionnaires.

Finally, the Clinical Evaluation Tools, Medicine Interaction Tables, and the Reference modules are your prompt to ongoing, independent learning.

About the authors and editor

Author, Dr Jürgen Fleisch (MD, PhD) undertook a fellowship in pain medicine in Portland, USA. Since 2007 he has practised anaesthesiology and pain therapy at the Leiden University Medical Centre (LUMC), the Netherlands. LUMC is an ESMO – a Designated Centre of Integrated Oncology and Palliative Care. Jürgen’s close cooperation with the Department of Oncology means that he regularly treats pain and related symptoms in cancer patients using classic medications and interventional pain treatments. He also has considerable experience prescribing cannabis-based medicines.

Author, Martin Woodbridge (MPHC, DPH) trained and lectured at the University of Otago’s Wellington School of Medicine, and worked for Medsafe, the medicines safety authority. In 2007, he wrote New Zealand’s regulatory policy and clinical guidelines on the medicinal use of cannabis for the Ministry of Health.

Since then, he has advised on programmes in Oceania and Asia and for the United Nations International Narcotics Control Board’s regulatory guidance on cannabis intended for medical and scientific use. He is also the author of the complimentary text ‘A primer to medicinal cannabis’. Martin has worked with Carl and Jürgen on different projects relating to the rational use of medicines.

Editor, Professor Emeritus Dr Carl Burgess (MB ChB, MD, MRCP, FRACP, FRCP) is a member of the New Zealand Order of Merit for Services to Pharmacology. He taught internal medicine and clinical pharmacology from 1982 to 2013 at the University of Otago’s Wellington School of Medicine, while also a consultant hospital physician to Capital and Coast Health, New Zealand. Carl has been involved in clinical pharmacology research since 1976. He provides deep knowledge of clinical pharmacology and the rational use of medicines, having investigated the clinical use of anti-depressives, anti-arrhythmic agents, anti-thrombotics, and bronchodilators, among other medicine classes. Carl is a previous member of the Standing Committee on Therapeutic Trials (SCOTT), which undertakes the scientific assessment of clinical trial applications for new pharmaceutical-type medicines.

Acknowledgements

The authors would like to thank health professionals from around the world for their valuable clinical contributions, drawing on their experiences as prescribers, pharmacists and nurses working with cannabis-based medicines (see section: insights from health professionals); and Associate Professor Dr Simon Adamson for his advice on screening tools (see: clinical evaluation tools).

Disclaimer

The Clinical Primer is produced by Woodbridge Research Ltd. This is a free-to-access educational resource funded under the policy of education without commercial bias. This project was made possible with funding provided by Bedrocan International.

This guide reflects published data, information and clinical insights as at the year 2025. It considers the rational use of cannabis-based medicines within a prescriber-pharmacy model of care.

While all efforts have been made to ensure the accuracy and scientific nature of information at the time of its production, the authors make no representations, implied or otherwise, as to the safety and efficacy of cannabis-based medicines and the methods of administration until such time that reliable clinical data is provided, nor to the contents of this text as certain information may have become outdated due to the rapid scientific and clinical developments in this field.

Neither the authors nor the publisher accepts liability for any damage that may result from the use of the information contained in this text, nor do they give any guarantees regarding the nature and the contents thereof. The author does not accept any liability for damage of any kind, caused by third party content attached to, written or printed.

Copyright

Copyright © 2025

All rights reserved. No part of this text may be reproduced, distributed or transmitted in any form or by any means, including printing, without the prior written consent of the author.

This text was made possible with funding from Bedrocan International under the policy of ‘education without commercial bias’.

Bedrocan International maintains copyright.

Photos: Bedrocan and Shutterstock.