Cannabis use disorder in patients with chronic pain: overestimation and underestimation in a cross-sectional observational study in 3 German pain management centres

[Benefits and harms of cannabis-based medicines from the viewpoint of patients with chronic pain and their physicians : A cohort study in three pain centers of the German federal state Saarland]

BACKGROUND

There are no studies available that have simultaneously assessed the benefits and harms of cannabis-based medicines from the viewpoint of patients and their physicians.

METHODS

All chronic pain patients at three pain centres in the German federal state of Saarland who had received at least one prescription of cannabis-based medicines (CbMs) in the past from the study centre were included in a cross-sectional study from January 1 to December 31, 2021. Patients and their physicians completed a self-developed questionnaire separately.

RESULTS

All 187 contacted patients participated in the study. Since the start of CbM therapy, 44.9% of patients reported to be much or very much, 43.3% to be moderately and 8.0% to be slightly improved overall. A total of 2.7% reported no change and 1.1% a moderate deterioration of overall wellbeing. From the patients' point of view, the symptoms most frequently reported to have substantially improved were sleep problems (36.4%), muscle tension (25.1%) and appetite problems (22.1%). The most frequent bothersome side effects were sweating (6.4%), concentration problems (4.2%) and nausea (4.1%). Physicians noted substantial pain relief in 60.7%, improvement of sleep in 65.7% and of mental well-being in 34.3%. A complete cessation of opioids was achieved in 64.7%, of anticonvulsants in 57.9% and of antidepressants in 60% of patients that had received these medications before the start of CbM therapy.

CONCLUSIONS

CbMs can contribute to a clinically relevant reduction in pain, sleep problems and muscle tension and can improve daily functioning in carefully selected and supervised patients with chronic pain. CbM can contribute to the reduction or complete cessation of other pain medications (antidepressants, anticonvulsants, opioids).

The prevalence of cannabis use disorders in people who use medicinal cannabis: A systematic review and meta-analysis

BACKGROUND

The prevalence of cannabis use disorders (CUDs) in people who use cannabis recreationally has been estimated at 22%, yet there is a dearth of literature exploring CUDs among people who use medicinal cannabis. We aimed to systematically review the prevalence of CUDs in people who use medicinal cannabis.

METHODS

In our systematic review and meta-analysis, we followed PRISMA guidelines and searched three databases (PsychInfo, Embase and PubMed) to identify studies examining the prevalence of CUDs in people who use medicinal cannabis. Meta-analyses were calculated on the prevalence of CUDs. Prevalence estimates were pooled across different prevalence periods using the DSM-IV and DSM-5.

RESULTS

We conducted a systematic review of 14 eligible publications, assessing the prevalence of CUDs, providing data for 3681 participants from five different countries. The systematic review demonstrated that demographic factors, mental health disorders and the management of chronic pain with medicinal cannabis were associated with an elevated risk of CUDs. Meta-analyses were conducted on the prevalence of CUDs. For individuals using medicinal cannabis in the past 6-12 months, the prevalence of CUDs was 29% (95% CI: 21-38%) as per DSM-5 criteria. Similar prevalence was observed using DSM-IV (24%, CI: 14-38%) for the same period. When including all prevalence periods and using the DSM-5, the prevalence of CUDs in people who use medicinal cannabis was estimated at 25% (CI: 18-33%).

CONCLUSIONS

The prevalence of CUDs in people who use medicinal cannabis is substantial and comparable to people who use cannabis for recreational reasons, emphasizing the need for ongoing research to monitor the prevalence of CUDs in people who use medicinal cannabis.

Opioid Use Disorder: A Qualitative Exploratory Analysis of Potential Misunderstandings in Patients with Chronic Non-Cancer Pain

Purpose

Substance use disorders (SUD) are a challenging comorbidity in patients with chronic non-cancer pain (CNCP) as they complicate diagnosis and therapy, especially when opioids are part of the therapeutic regimen. A definite diagnosis of opioid use disorder (OUD) in patients with CNCP on long-term opioid therapy (LTOT) is a prerequisite for effective and targeted therapy but may be complicated as some criteria of OUD might be attributed to the desire of the patient to relieve the pain. For instance, the desire to increase the dose can be based on both a SUD as well as inadequate pain therapy. Many scientific studies use standardized questions. Therefore, potential misunderstandings due to possible diagnostic overlaps often cannot be clarified.

Methods

14 qualitative guided interviews were conducted and analyzed (Kuckartz content analysis), with the intention to verify if patient's initial response to simple questions based on the wording of the DSM-5, as commonly used in research and practice, were consistent with the results of a more in-depth inquiry.

Results

The results suggest that without in-depth investigation, there is a particular risk of false-positive assessment of the DSM-5 criteria for OUD when opioids are prescribed, especially when the questions are considered independently of chronic pain. The risk of a false-negative assessment has also been shown in isolated cases.

Conclusion

Only after asking for and describing specific situations it was possible to determine whether the patient's positive or negative answers were based on a misunderstanding of the question. To avoid misdiagnosis, staff conducting DSM-5 interviews should be trained in pain-specific follow-up questions that may help to uncover diagnostic confounding.

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.