OUP accepted manuscript

[Impact of dronabinol shortage on a population of chronic pain patients: A retrospective observational study]

OBJECTIVE

A supply shortage of dronabinol occurred between December 2023 and February 2024, forcing chronic pain patients to discontinue this treatment. We assessed the impact of this shortage on patients in our hospital.

METHOD

A retrospective observational study of patients treated with dronabinol was conducted. Collected data included socio-demographic, pharmacological and clinical data. Pain intensity and its interference, the intensity of other pain dimensions (mood, relationship with others, etc.) and quality of sleep were collected before discontinuation (dronabinol dosage balanced, M0) and at the end of discontinuation (dronabinol stopped for several weeks, M3). The patient's perception of his state of health evolution was collected at the end of the shortage.

RESULTS

Health deterioration was reported by 86% of patients after 3 months of rupture. Pain intensity and its interference with patients' daily lives increased significantly. Patients' sleep deteriorated significantly. The number of patients with permanent pain increased 5-fold (n=2 at M0 and n=10 at M3). The number of patients with more than 20 painful attacks per 24hours increased 2-fold (n=2 at M0 and n=4 at M3).

CONCLUSION

Although data on the efficiency of dronabinol are currently limited, this supply disruption has had negative clinical consequences for our patients. With drug shortages multiplying in recent years, the marketing of new specialties and therefore the availability of therapeutic alternatives could help reduce the clinical impact of a possible new dronabinol shortage in these refractory chronic pain patients.

Overview of global monitoring systems for the side effects and adverse events associated with medicinal cannabis use: a scoping review using a systematic approach

OBJECTIVES

The use of cannabis-based medicine (CBM) as a therapeutic has surged in Australia over the past 5 years. Historically, the United Nations Single Convention on Narcotic Drugs (1961) prohibited cannabis use in Europe, the USA, the UK and Australia, leading to legislative resistance and limited preclinical data on CBM. Existing safety monitoring systems for CBM are poorly structured and do not integrate well into the workflows of busy health professionals. As a result, postmarketing surveillance is inconsistent. This review aims to evaluate international systems for monitoring CBM side effects and adverse events.

DESIGN

To undertake a scoping review with a systematic approach, we used the Population, Intervention, Comparison, Outcome (PICO) framework to develop keyword elements, and two search queries to maximise search sensitivity and specificity.

DATA SOURCES

Search queries were entered into Embase and Scopus for peer-reviewed literature, and additional searches for grey literature were conducted on 23 June 2023.

ELIGIBILITY CRITERIA

We included 54 full-text articles in the review: 39 from peer-reviewed searches, 8 from grey literature and 7 from citations of relevant texts.

DATA EXTRACTION AND SYNTHESIS

Our search yielded two main forms of monitoring systems: databases and registries. Out of the 24 monitoring systems identified, there were 10 databases and 14 registries, with databases often created by regulatory authorities. Systems differed in methods of causality assessment, level of detail collected, terminology and affiliations.

RESULTS

Within the monitoring systems with enough published data for analysis, all except one remain active at the time of this review. VigiBase is the largest centralised monitoring system, receiving international case reports, however data heterogeneity persists.

CONCLUSIONS

Our study emphasises the need for a centralised, consistent and accessible system for the postmarketing surveillance of side effects and adverse events associated with medicinal cannabis use.

The Use of Tetrahydrocannabinol Is Associated with an Increase in Survival Time in Palliative Cancer Patients: A Retrospective Multicenter Cohort Study

Introduction

Tetrahydrocannabinol (THC) is often prescribed for ambulatory palliative patients to improve sleep quality and appetite and to reduce anxiety, stress, and pain. However, it is not known if THC has also an effect on the mortality of these patients.

Method

The objective was the impact of THC on mortality of ambulatory palliative patients. For this purpose, data from the palliative treatment documentation from 5 ambulatory palliative care teams in Brandenburg, Germany were used for this analysis. Survival time was calculated for 3 groups of patients: (1) without THC; (2) with THC in a low dosage (≤4.7 mg per day); and (3) THC in higher doses (≥4.7 mg per day). The analysis was done for 2 cohorts of patients. Cohort 1: all patients with a survival time of at least 7 days after inclusion in specialized ambulatory palliative care (SAPC) and cohort 2: a subgroup of patients with a survival time between 7 and 100 days. Kaplan-Meier curves were created, and multivariate analysis was done to investigate the impact of THC on mortality.

Results

A total of 9,419 patients with a survival time of at least 7 days after inclusion in SAPC were included in the analysis (cohort 1). 7,085 among them had a survival time between 7 and 100 days (cohort 2). In both cohorts, survival time was significantly prolonged by THC, but only when the daily THC dose was above the median of 4.7 mg. Survival time was 15 days longer in cohort 2 (40 vs. 25 days), when more than 4.7 mg THC were prescribed per day.

Conclusion

Use of THC is associated with a significant increase in survival time in ambulatory palliative patients which survive longer than 7 days the initiation of THC prescription and which use of THC >4.7 mg/day.

Drug Interactions of Tetrahydrocannabinol and Cannabidiol in Cannabinoid Drugs

BACKGROUND

Cannabinoid drugs containing tetrahydrocannabinol (THC), or its structural analogues, as monotherapeutic agents or as extracts or botanical preparations with or without cannabidiol (CBD) are often prescribed to multimorbid patients who are taking multiple drugs. This raises the question of the risk of drug interactions.

METHODS

This review of the pharmacokinetics and pharmacodynamics of interactions with cannabinoid drugs and their potential effects is based on pertinent publications retrieved by a selective literature search.

RESULTS

As THC and CBD are largely metabolized in the liver, their bioavailability after oral or oral-mucosal administration is low (6-8% and 11-13%, respectively). The plasma concentrations of THC and its active metabolite 11-OH-THC can be increased by strong CYP3A4 inhibitors (verapamil, clarithromycin) and decreased by strong CYP3A4 inductors (rifampicin, carbamazepine). The clinical significance of these effects is unclear because of the variable plasma level and therapeutic spectrum of THC. The metabolism of CBD is less dependent on cytochrome P450 enzymes than that of THC. THC and CBD inhibit CYP2C and CYP3A4; the corresponding clinically relevant drug interactions probably are likely to arise only with THC doses above 30 mg/day and CBD doses above 300 mg/day.

CONCLUSION

Potential drug interactions with THC and CBD are probably of little importance at low or moderate doses. Strong CYP inhibitors or inductors can intensify or weaken their effect. Slowly ramping up the dose of oral cannabinoid drugs can lessen their pharmacodynamic interactions, which can generally be well controlled. Administration by inhalation can worsen the interactions.

Safety and effectiveness of cannabinoids to Danish patients with treatment refractory chronic pain-A retrospective observational real-world study

BACKGROUND

Cannabinoids are considered a therapeutic option to patients suffering from treatment refractory chronic pain (TRCP) insufficiently relieved by conventional analgesics or experiencing intolerable adverse events (AEs) from those. This study aimed to explore safety and effectiveness of oral cannabinoids among patients with TRCP.

METHODS

A retrospective study was conducted among Danish patients with TRCP being prescribed oral cannabinoids. Data on AEs and changes in pain intensity by numeric rating scale (NRS) before and after initiation of oral cannabinoid therapy were analysed.

RESULTS

Among 826 eligible patients ≥18 years old, 529 (64%) were included for data analysis at first follow-up (F/U1) (median 56 days from baseline) and 214 (26%) for second follow-up (F/U2) (median 126 days from F/U1). Mean age was 60 ± 15.9 years and 70% were females. AEs were in general reported mild to moderate by 42% of patients at F/U1 and 34% at F/U2. AEs were mainly related to gastrointestinal (F/U1: 17% and F/U2: 13%) and nervous system disorders (F/U1: 14% and F/U2: 11%). Reduction in NRS was significantly different at both follow-up consultations compared with baseline (<0.0001). Clinically relevant pain reduction (NRS ≥30%) was reported by 17% at F/U1 and 10% of patients at F/U2 in intention-to-treat analysis whereas the figures were 32% and 45% respectively, in per-protocol analysis.

CONCLUSION

Oral cannabinoid therapy seems to be safe and mildly effective in patients with TRCP. Randomized controlled trials with focus on comparable pain characteristics in diagnostical homogenous patient subgroups are needed for further improvement of evidence level for relief of chronic pain using oral cannabinoids.

SIGNIFICANCE

The findings in this retrospective study conducted in a real-world clinical setting suggest a favourable safety profile of cannabinoids. Moreover, one-sixth (intention-to-treat) and one-third (per-protocol) of patients with chronic pain refractory to conventional analgesics, or experiencing intolerable adverse effects, benefited significantly from therapy with oral cannabinoid regimens. Combination of THC and CBD seems overall more effective than cannabinoid monotherapy. Conduction of randomized controlled trials investigating safety and efficacy of cannabinoid therapy to diagnosis specific patient subgroups with comparable clinical and pathophysiological chronic pain characteristics is warranted, hence contributing further to the process of clinical evidence clarification currently in progress.

Efficacy and safety/tolerability of pridinol: a meta-analysis of double-blind, randomized, placebo-controlled trials in adult patients with muscle pain

OBJECTIVE

To evaluate analgesic efficacy and safety/tolerability of the nonbenzodiazepine antispasmodic pridinol (PRI) in patients with muscle-related pain.

METHODS

Systematic review and meta-analysis of randomized placebo-controlled trials (RCTs) according to PRISMA guidelines and Cochrane recommendations. Data sources included Google Scholar, Embase, PubMed, ClinicalTrials.gov, EU Clinical Trials Registry, Chinese Clinical Trial Registry, UMIN Clinical Trials Registry, and product manufacturer archives from inception to 31 January 2022. Eligibility criteria for study selection were randomized, placebo-controlled trials with PRI in adults (≥18 years) with muscle-related pain. Data extraction, synthesis, and analysis carried out by two reviewers independently identified studies, extracted data, and assessed the risk of bias using the Cochrane risk of bias tool. Categorial global response rates (number of patients) based on clinical judgement of study physicians (as primary efficacy endpoint), and response on pain at rest, pain at movement, stiffness, tenderness, and movement restriction (as secondary efficacy endpoints), as well as the number of patients with drug-related adverse events (DRAEs) were meta-analytically evaluated using the Review Manager Software version 5.4.1.

RESULTS

In total, 38 records were identified, but only two placebo-controlled studies (with 342 patients with mild to moderate acute muscle pain [55.3% female, age 50.6 ± 16.6 years], of whom 173 received PRI and 169 placebo, each as monotherapy) proved to be suitable for quantitative and qualitative analysis. Treatment with PRI was (irrespective of its mode of administration as oral tablet or intramuscular injection) associated with a significantly higher global response rate compared to placebo (74.0 vs. 49.7%; OR 2.86, 95%-CI: 1.82-4.51; p < .00001; Cohen´s h: 0.506, NNT: 4.1; Chi² for heterogeneity 1.41 (p = .24], I²  = 29%), and significantly higher response rates were also found for all secondary efficacy endpoints. The safety of PRI was comparable to that of placebo: DRAEs were only seen in one of the two studies and reported for 13 vs. 10 patients (OR: 0.76 95%-CI: 0.32-18.1; p = .54, NNH: 62.6), and related discontinuations were reported for four vs. one patient (2.3 vs. 0.6%; p = .231).

CONCLUSIONS

The results from this meta-analysis as based on two placebo-controlled studies in adult patients with mild to moderate acute muscle pain demonstrate that a 3-week monotherapy with PRI showed a comparable safety profile, but significantly better analgesic effects and improvements of related impairments such as stiffness, tenderness, and movement restrictions compared with placebo - irrespective of its mode of administration.