OBJECTIVE: Chronic non-cancer pain (CNCP) is one of the most common causes of disability globally. Opioid prescribing to treat CNCP remains widespread, despite limited evidence of long-term clinical benefit and evidence of harm such as problematic pharmaceutical opioid use (POU) and overdose. The study aimed to measure the prevalence of POU in CNCP patients treated with opioid analgesics.
METHODS: A comprehensive systematic literature review and meta-analysis was undertaken using MEDLINE, Embase and PsycINFO databases from inception to 27 January 2021. We included studies from all settings with participants aged ≥ 12 with non-cancer pain of ≥ 3 months duration, treated with opioid analgesics. We excluded case-control studies, as they cannot be used to generate prevalence estimates. POU was defined using four categories: dependence and opioid use disorder (D&OUD), signs and symptoms of D&OUD (S&S), aberrant behaviour (AB) and at risk of D&OUD. We used a random-effects multi-level meta-analytical model. We evaluated inconsistency using the I2 statistic and explored heterogeneity using subgroup analyses and meta-regressions.
RESULTS: A total of 148 studies were included with > 4.3 million participants; 1% of studies were classified as high risk of bias. The pooled prevalence was 9.3% [95% confidence interval (CI) = 5.7-14.8%; I2 = 99.9%] for D&OUD, 29.6% (95% CI = 22.1-38.3%, I2 = 99.3%) for S&S and 22% (95% CI = 17.4-27.3%, I2 = 99.8%) for AB. The prevalence of those at risk of D&OUD was 12.4% (95% CI = 4.3-30.7%, I2 = 99.6%). Prevalence was affected by study setting, study design and diagnostic tool. Due to the high heterogeneity, the findings should be interpreted with caution.
CONCLUSIONS: Problematic pharmaceutical opioid use appears to be common in chronic pain patients treated with opioid analgesics, with nearly one in 10 experiencing dependence and opioid use disorder, one in three showing signs and symptoms of dependence and opioid use disorder and one in five showing aberrant behaviour.

UNASSIGNED: The first-line treatment for opioid dependence is opioid agonist treatment (OAT) with oral opioids. However, in some cases, treatment with intravenous diacetylmorphine (IV-DAM) is indicated. Research on neurocognitive impairments and treatment effects of OAT - particularly with IV-DAM - on neurocognitive functioning, is scarce. The current study is the first to investigate the neurocognitive performance of individuals on OAT with IV-DAM. Using a prospective study design with two timepoints of measurement, the first aim was to assess the nature and extent of neurocognitive functioning in individuals with opioid dependence by comparing participants\' neurocognitive performance with normative data of the general population on admission to treatment (baseline) and after an initial three-month period of OAT (study end). The second aim was to examine whether and to what extent neurocognitive performance would improve after three months on OAT. The third aim was to investigate whether, and if so, to what extent the treatment method (IV-DAM vs. oral opioids) would lead to higher neurocognitive improvements at study end.
UNASSIGNED: Forty-seven opioid-dependent individuals (baseline; 33 individuals at study end) participated in this study (mean age: 34.3 years; 27.7% female). Participants underwent neuropsychological testing with a battery of 12 tests covering different neurocognitive domains, including attention, memory, and executive functions.
UNASSIGNED: Compared to normative data, opioid-dependent individuals showed impairments in almost every test both at baseline and at study end. At baseline, neurocognitive performance did not differ between individuals receiving IV-DAM or oral opioids for OAT. Compared to baseline, the neurocognitive performance did neither improve nor deteriorate after three months of treatment with neither IV-DAM nor oral opioids. However, a trend towards improvement was found for the memory domain.
UNASSIGNED: Given that neurocognitive impairments should be considered in treatment planning and therapeutic interventions. Since a reduced cognitive performance may affect both the treatment outcome and the therapeutic relationship unfavorably, specific neurocognitive training at the beginning of treatment should be considered.

Opioid dependence is a common problem, and therapeutic alternatives are scarce and ineffective. Ibogaine, illegal in several countries, has been reported as a possible therapy in alternative clinics and it is also used as a recreational drug, despite its cardiotoxic potential, including QT prolongation. We report a case of long QT leading to multiple episodes of cardiac arrest after a single dose of ibogaine (200mg, 2.6mg/Kg) in a patient without structural heart disease. This case highlights the fact that even low doses of ibogaine can be lethal and warns us about the consequences of its use.

OBJECTIVE: Dose optimization plays a key role in determining clinical outcomes in patients on opioid agonist treatment (OAT). The objective of this study was to identify the variables independently associated with buprenorphine/naloxone (B/N) dose adequacy in patients with opiate use disorder (OUD).
METHODS: Cross-sectional study of a convenience sample of patients with OUD treated with B/N (n = 315) in four regions in Spain. The Opiate Dosage Adequacy Scale (ODAS) was used to determine B/N dose adequacy. The ODAS evaluate the six components of the \"dose adequacy\" construct, as follows: continued use of heroin; narcotic blockade or crossed tolerance; objective opioid withdrawal symptoms (OWS); subjective OWS; craving for heroin; and overmedication. A binomial logistic regression analysis was performed to identify the variables associated with the condition \"ODAS Adequate B/N dose\". Participants completed a battery of instruments to assess sociodemographic, substance use, clinical, and treatment variables.
RESULTS: The B/N dose was considered adequate in 231 of the 315 participants (73.3 %). Two variables, satisfaction with B/N as a medication (OR=5.764, 95 % CI=2.211-15.030) and patient-perceived participation in B/N dose decisions (OR=1.790, 95 % CI=1221-2623), were independently, significantly, and positively associated with the \"ODAS Adequate B/N dose\" condition. While the severity of heroin dependence was significantly associated with buprenorphine dose adequacy in the bivariate analyses, significance was lost in the full regression model.
CONCLUSIONS: Satisfaction with B/N as a medication and patient-perceived involvement in the dose decision are associated with clinician-assessed dose adequacy. In the context of good clinical practice, it is important to take into account both of these variables to individualize the prescribed dose through a shared decision-making process.

BACKGROUND: Chronic pain is a debilitating and common health issue. General Practitioners (GPs) often prescribe opioids to treat chronic pain, despite limited evidence of benefit and increasing evidence of harms, including prescription Opioid Use Disorder (pOUD). Australian GPs are worried about the harms of long-term opioids, but few are involved in the treatment of pOUD. There is little research on GPs\' experiences diagnosing and managing pOUD in their chronic pain patients.
METHODS: This qualitative research used semi-structured interviews and a case study to investigate GPs\' experiences through the lens of the Theory of Planned Behaviour (TPB). TPB describes three factors, an individual\'s perceived beliefs/attitudes, perceived social norms and perceived behavioural controls. Participants were interviewed via an online video conferencing platform. Interviews were transcribed verbatim and thematically analysed.
RESULTS: Twenty-four GPs took part. Participants were aware of the complex presentations for chronic pain patients and concerned about long-term opioid use. Their approach was holistic, but they had limited understanding of pOUD diagnosis and suggested that pOUD had only one treatment: Opioid Agonist Treatment (OAT). Participants felt uncomfortable prescribing opioids and were fearful of difficult, conflictual conversations with patients about the possibility of pOUD. This led to avoidance and negative attitudes towards diagnosing pOUD. There were few positive social norms, few colleagues diagnosed or managed pOUD. Participants reported that their colleagues only offered positive support as this would allow them to avoid managing pOUD themselves, while patients and other staff were often unsupportive. Negative behavioural controls were common with low levels of knowledge, skill, professional supports, inadequate time and remuneration described by many participants. They felt OAT was not core general practice and required specialist management. This dichotomous approach was reflected in their views that the health system only supported treatment for chronic pain or pOUD, not both conditions.
CONCLUSIONS: Negative beliefs, negative social norms and negative behavioural controls decreased individual behavioural intention for this group of GPs. Diagnosing and managing pOUD in chronic pain patients prescribed opioids was perceived as difficult and unsupported. Interventions to change behaviour must address negative perceptions in order to lead to more positive intentions to engage in the management of pOUD.

OBJECTIVE: Among people receiving opioid-agonist treatment (OAT), the risk of COVID-19 infection and disease may be higher owing to underlying health problems and vulnerable social circumstances. We aimed to determine whether recent OAT, when compared with past exposure, affected the risk of (i) testing for SARS-CoV-2, (ii) testing positive for SARS-CoV-2, and (iii) being hospitalized or dying with COVID-19 disease.
METHODS: We included individuals prescribed OAT in Scotland from 2015 to 2020. We performed record linkage to SARS-CoV-2 PCR testing, vaccination, hospitalization, and mortality data, and followed up from March 2020 to December 2021. We used proportional hazards analysis and multivariate logistic regression to estimate associations between recent OAT prescription (in the previous 2 months), compared with past exposure (off treatment for over a year), and COVID-19 outcomes. Models were adjusted for confounders.
RESULTS: Among 36 093 individuals prescribed OAT, 19 071 (52.9%) were tested for SARS-CoV-2; 2896 (8.3%) tested positive; and 552 (1.5%) were hospitalized or died with COVID-19. Recent OAT, compared with past exposure, was associated with lower odds of testing positive among those tested (aOR, 0.63; 95% CI, 0.57-0.69). However, among those testing positive, recent OAT was associated with two-fold higher odds of hospitalization or death (aOR, 2.04; 95% CI, 1.60-2.59).
CONCLUSIONS: We found that recent OAT was associated with lower odds of SARS-CoV-2 infection, but with higher odds of disease once diagnosed. Clinical studies are needed to unravel the role of OAT in these associations. An enhanced effort is warranted to increase vaccine coverage among OAT patients to mitigate the severe consequences of COVID-19.

BACKGROUND: The COVID-19 pandemic has affected the availability and access to medications for opioid dependence (OD). We examined the monthly trends in new buprenorphine/naloxone (BNX) treatment episodes, number of clinical visits for BNX, BNX dispensed per person, and BNX prescription over 56-month, which included pre-pandemic, during early, and later part of pandemic (Jan 2017 - Aug 2022).
METHODS: Research data were collected from the pharmacy database of a large publicly funded treatment center in India. A flexible, low-threshold service was adopted in April 2020 in response to the lockdown implemented on 25 March 2020. Change Point analyses were performed to examine monthly trends visually and statistically. We used Autoregressive integrated moving averages to forecast trends from April to Aug 2020 and March to August 2022, using Jan 2017 to March 2020 and March 2020 to February 2022 as training datasets.
RESULTS: 993 patients were started on BNX treatment, 40452 BNX clinic attendances were made, 1401393 BNX tablets were dispensed, and 6795 new patients with OD were registered. The observed data for clinic attendance for BNX was significantly lower than the projected estimates in April -Aug 2020; however, observed new treatment episodes and monthly BNX prescriptions were within the 95% projected estimates; BNX dispensed per person was significantly more than the projected estimate. In contrast, observed BNX prescription trends surpassed the upper limit of 95% CI in March-Aug 2022.
CONCLUSIONS: A low-threshold and flexible treatment service could mitigate the unintended consequences of pandemic-induced restrictions.

Takotsubo cardiomyopathy (TTC) is characterized by a transient reduction in left ventricular systolic function with apical akinesis. TTC is usually associated with stress and emotional responses; however, opioid withdrawal has been identified as a rare cause of precipitation of TTC. We describe the case of an elderly female with chronic opioid dependence, who presented with symptoms of toxicity and developed TTC upon opioid withdrawal. Her symptoms improved with clonidine. In the time of an ongoing opioid crisis and an attempt to reduce opioid use among patients, this case reinforces the importance of anticipating TTC as a possibly life-threatening complication of sudden discontinuation of opioids in patients who have developed dependence on it.

Aims: To characterise and understand the untreated high-risk opioid user population in Finland, and to determine the reasons why these people do not enter treatment. Methods: The study setting was a half-year cross-sectional survey in Finland during 2021-2022. An electronic questionnaire with 24 structured questions was concluded in 16 needle exchange units. Participants were opioid-dependent people without opioid agonist treatment (OAT), and they answered the survey voluntarily and anonymously. Results: Of the 167 respondents, 62% were men, 53% were aged ≤34 years, 66% had used opioids for >6 years, and 78% used drugs intravenously (IV) daily. The most used opioid (95%) was buprenorphine. Most respondents used opioids as self-medication for withdrawal symptoms (75%), or to treat psychological symptoms (59%) or pain (43%). Of them, 70% also used other substances for recreational purposes. The most common named reasons to stay outside OAT were as follows: seeking treatment is too difficult (37%); treatment is too binding (36%); and fear of actions from authorities (23%). Conclusions: For opioid-dependent respondents who would be eligible for OAT in Finland, treatment awareness is limited. These high-risk opioid users also think that the treatment would be too binding. In conclusion, there is a need for increase in general information about, accessibility to, acceptance for and individualisation of OAT.

OBJECTIVE: Avoidance of opioid withdrawal plays a key role in human opioid addiction. Here, we present a procedure for studying operant negative reinforcement in rats that was inspired by primate procedures where opioid-dependent subjects lever-press to prevent naloxone infusions.
METHODS: In Experiment 1, we trained rats (n = 30, 15 females) to lever-press to escape and then avoid mild footshocks (0.13-0.27 mA) for 35 days (30 trials/d). Next, we catheterized them and implanted minipumps containing methadone (10 mg/kg/day) or saline. We then paired (4 times, single session) a light cue (20-s) with a naloxone infusion (20 µg/kg, i.v) that precipitated opioid withdrawal. Next, we trained the rats to escape naloxone injections for 10 days (30 trials/d). Each trial started with the onset of the opioid-withdrawal cue. After 20-s, the lever extended, and an infusion of naloxone (1 to 2.2 µg/kg/infusion) began; a lever-press during an 11-s window terminated the withdrawal-paired cue and the infusion. In Experiment 2, we trained rats (n = 34, 17 females) on the same procedure but decreased the footshock escape/avoidance training to 20 days.
RESULTS: All rats learned to lever-press to escape or avoid mild footshocks. In both experiments, a subset, 56% (10/18) and 33% (8/24) of methadone-dependent rats learned to lever-press to escape naloxone infusions.
CONCLUSIONS: We introduce an operant negative reinforcement procedure where a subset of opioid-dependent rats learned to lever-press to escape withdrawal-inducing naloxone infusions. The procedure can be used to study mechanisms of individual differences in opioid negative reinforcement-related behaviors in opioid-dependent rats.