Original Research ARTICLE
A Systematic Review on the Pharmacokinetics of Cannabidiol in Humans
- 1University of Nottingham, United Kingdom
- 2Division of Medical Sciences and Graduate Entry Medicine, School of Medicine, University of Nottingham, United Kingdom
- 3Artelo Biosciences, United States
Background: Cannabidiol is being pursued as a therapeutic treatment for multiple conditions, usually by oral delivery. Animal studies suggest oral bioavailability is low, but literature in humans is not sufficient. The aim of this review was to collate published data in this area.
Methods: A systematic search of PubMed and EMBASE (including MEDLINE) was conducted to retrieve all articles reporting pharmacokinetic data of CBD in humans.
Results: Of 792 articles retireved, 24 included pharmacokinetic parameters in humans. The half-life of cannabidiol was reported between 1.4-10.9 hours after oromucosal spray, 2-5 days after chronic oral administration, 24 hours after i.v., and 31 hours after smoking. Bioavailability following smoking was 31% however no other studies attempted to report the absolute bioavailability of CBD following other routes in humans, despite i.v formulations being available. The area-under-the-curve and Cmax increase in dose-dependent manners and are reached quicker following smoking/inhalation compared to oral/oromucosal routes. Cmax is increased during fed states and in lipid formulations. Tmax is reached between 0-4 hours.
Conclusions: This review highlights the paucity in data and some discrepancy in the pharmacokinetics of cannabidiol, despite its widespread use in humans. Analysis and understanding of properties such as bioavailability and half-life is critical to future therapeutic success, and robust data from a variety of formulations is required.
Keywords: pharmacokinetics, Cannabidiol (CBD), endocannabinoid system, bioavailability, CMAX, TMAX, Half life, plasma clearance, volume of distribution
Received: 19 Sep 2018;
Accepted: 07 Nov 2018.
Edited by:Thomas Dorlo, The Netherlands Cancer Institute (NKI), Netherlands
Reviewed by:Constantin Mircioiu, Carol Davila University of Medicine and Pharmacy, Romania
Pius S. Fasinu, Campbell University, United States
Copyright: © 2018 Millar, Stone, Yates and O'Sullivan. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Ms. Sophie A. Millar, University of Nottingham, Nottingham, United Kingdom, firstname.lastname@example.org