Inhaled Δ9-tetrahydrocannabinol does not enhance oxycodone-induced respiratory depression: randomised controlled trial in healthy volunteers.

BACKGROUND: In humans, the effect of cannabis on ventilatory control is poorly studied, and consequently, the effect of Δ9-tetrahydrocannabinol (THC) remains unknown, particularly when THC is combined with an opioid. We studied the effect of THC on breathing without and with oxycodone pretreatment. We hypothesised that THC causes respiratory depression, which is amplified when THC and oxycodone are combined. METHODS: In this randomised controlled crossover trial, healthy volunteers were administered inhaled Bedrocan® 100 mg (Bedrocan International B.V., Veendam, The Netherlands), a pharmaceutical-grade high-THC cannabis variant (21.8% THC; 0.1% cannabidiol), after placebo or oral oxycodone 20 mg pretreatment; THC was inhaled 1.5 and 4.5 h after placebo or oxycodone intake. The primary endpoint was isohypercapnic ventilation at an end-tidal Pco2 of 55 mm Hg or 7.3 kPa (VE55), measured at 1-h intervals for 7 h after placebo/oxycodone intake. RESULTS: In 18 volunteers (age 22 yr [3]; 9 [50%] female), oxycodone produced a 30% decrease in VE55, whereas placebo was without effect on VE55. The first cannabis inhalation resulted in VE55 changing from 20.3 (3.1) to 23.8 (2.4) L min-1 (P=0.06) after placebo, and from 11.8 (2.8) to 13.0 (3.9) L min-1 (P=0.83) after oxycodone. The second cannabis inhalation also had no effect on VE55, but slightly increased sedation. CONCLUSIONS: In humans, THC has no effect on ventilatory control after placebo or oxycodone pretreatment. CLINICAL TRIAL REGISTRATION: 2021-000083-29 (EU Clinical Trials Register.).

Cannabis-opioid interaction in the treatment of fibromyalgia pain: an open-label, proof of concept study with randomization between treatment groups: cannabis, oxycodone or cannabis/oxycodone combination-the SPIRAL study.

BACKGROUND: Opioids continue to be widely prescribed for chronic noncancer pain, despite the awareness that opioids provide only short-time pain relief, lead to dose accumulation, have numerous adverse effects, and are difficult to wean. As an alternative, we previously showed advantages of using pharmaceutical-grade cannabis in a population of chronic pain patients with fibromyalgia. It remains unknown whether combining an opioid with pharmaceutical-grade cannabis has advantages, such as fewer side effects from lesser opioid consumption in chronic pain. METHODS: Trial design: a single-center, randomized, three-arm, open-label, exploratory trial. Trial population: 60 patients with fibromyalgia according to the 2010 definition of the American College of Rheumatologists. INTERVENTION: Patients will be randomized to receive up to 4 daily 5 mg oral oxycodone sustained release (SR) tablet, up to 5 times 150 mg inhaled cannabis (Bediol®, containing 6.3% Δ9-tetrahydrocannabinol and 8% cannabidiol), or the combination of both treatments. Treatment is aimed at self-titration with the daily maximum doses given. Treatment will continue for 6 weeks, after which there is a 6-week follow-up period. Main trial endpoint: The number of side effects observed during the course of treatment using a composite adverse effect score that includes the following 10 symptoms: dizziness (when getting up), sleepiness, insomnia, headache, nausea, vomiting, constipation, drug high, hallucinations, and paranoia. Secondary and tertiary endpoints include pain relief and number of oxycodone doses and cannabis inhalations. DISCUSSION: The trial is designed to determine whether self-titration of oxycodone and cannabis will reduce side effects in chronic pain patients with fibromyalgia. TRIAL REGISTRATION {2A AND 2B}: EU trial register 2019-001861-33, URL https://www.clinicaltrialsregister.eu , on July 17, 2019; World Health Organization International Clinical Trials Research Platform NL7902, URL https://trialsearch.who.int , on July 26, 2019.

Opioid utility function: methods and implications.

Opioids are complex drugs that produce profit (most importantly analgesia) as well as a myriad of adverse effects including gastrointestinal motility disturbances, abuse and addiction, sedation and potentially lethal respiratory depression (RD). Consequently, opioid treatment requires careful evaluation in terms of benefit on the one hand and harm on the other. Considering benefit and harm from an economic perspective, opioid treatment should lead to profit maximization with decision theory defining utility as (profit - loss). We here focus on the most devastating opioid adverse effect, RD and define opioid utility U = P(benefit) - P(harm), where P(benefit) is the probability of opioid-induced analgesia and P(harm) the probability of opioid-induced RD. Other utility functions are also discussed including the utility U = P(benefit AND NOT harm), the most wanted opioid effect, i.e., analgesia without RD, and utility surfaces, which depict the continuum of probabilities of presence or absence of analgesia in combination with the presence or absence of RD. Utility functions are constructed from pharmacokinetic and pharmacodynamic data sets, although pragmatic utility functions may be constructed when pharmacokinetic data are not available. We here discuss utilities of several opioids including the partial mu-opioid-receptor agonist buprenorphine, the full opioid receptor agonists fentanyl and alfentanil, and the bifunctional opioid cebranopadol, which acts at mu-opioid and nociception/orphanin FQ-receptors. We argue that utility functions give clinicians the opportunity to make an informed decision when opioid analgesics are needed for pain relief, in which opioids with a positive utility function are preferred over opioids with negative functions. Furthermore, utility functions of subpopulations will give an extra insight as a utility functions measured in one subgroup (e.g., patients with postoperative pain, good opioid responders) may not be mirrored in other patient subgroups (e.g., neuropathic pain patients, poor opioid responders).