Antidepressant Use Among People Prescribed Opioids for Chronic Noncancer Pain

Observational evidence linking psychotropic medicines to the dispensing of opioid agents in later life

BACKGROUND

The use of opioid medicines is common in developed countries, particularly among older adults and those with mental health disorders. It is unclear if the association between mental disorders and opioid medicines is causal, or is due to reverse causality or confounding.

METHODS

We used a 10% random sample of the Australian Pharmaceutical Benefits Scheme (years 2012-2022) to examine the cross-sectional, case-control and longitudinal association between the dispensing of antidepressants, anxiolytics, hypnotics, antipsychotics and lithium, and opioid medicines. We used logistic regression, structural equation models (SEM), and Cox regression to analyze the data. Analyses were adjusted for age (years), sex, and number of non-psychotropic medicines dispensed during the year.

RESULTS

The 2022 file contained 804 334 individuals aged 50 years or over (53.1% women), of whom 181 690 (22.6%) received an opioid medicine. The adjusted odds ratio of being dispensed opioid medicines was 1.44 (99% CI = 1.42-1.46) for antidepressants, 1.97 (99% CI = 1.92-2.03) for anxiolytics, 1.55 (99% CI = 1.51-1.60) for hypnotics, 1.32 (99% CI = 1.27-1.38) for antipsychotics, and 0.60 (99% CI = 0.53-0.69) for lithium. Similar associations were noticed when we compared participants who were or not dispensed opioid medicines in 2022 for exposure to psychotropic agents between 2012 and 2021. SEM confirmed that this association was not due to reverse causality. The dispensing of antidepressants was associated with increased adjusted hazard (HR) of subsequent dispensing of opioid medicines (HR = 1.29, 99% CI = 1.27-1.30). Similar associations were observed for anxiolytics, hypnotics and antipsychotics, but not lithium.

CONCLUSIONS

The dispensing of opioid medicines is higher among older individuals exposed to antidepressants, anxiolytics, hypnotics and antipsychotics than those who are not. These associations are not due to reverse causality or study design. Preventive strategies seeking to minimise the risk of inappropriate use of opioid medicines in later life should consider targeting this high-risk population.

Five-Year Trajectories of Prescription Opioid Use

Importance

There are known risks of using opioids for extended periods. However, less is known about the long-term trajectories of opioid use following initiation.

Objective

To identify 5-year trajectories of prescription opioid use, and to examine the characteristics of each trajectory group.

Design, Setting, and Participants

This population-based cohort study conducted in New South Wales, Australia, linked national pharmaceutical claims data to 10 national and state data sets to determine sociodemographic characteristics, clinical characteristics, drug use, and health services use. The cohort included adult residents (aged ≥18 years) of New South Wales who initiated a prescription opioid between July 1, 2003, and December 31, 2018. Statistical analyses were conducted from February to September 2022.

Exposure

Dispensing of a prescription opioid, with no evidence of opioid dispensing in the preceding 365 days, identified from pharmaceutical claims data.

Main Outcomes and Measures

The main outcome was the trajectories of monthly opioid use over 60 months from opioid initiation. Group-based trajectory modeling was used to classify these trajectories. Linked health care data sets were used to examine characteristics of individuals in different trajectory groups.

Results

Among 3 474 490 individuals who initiated a prescription opioid (1 831 230 females [52.7%]; mean [SD] age, 49.7 [19.3] years), 5 trajectories of long-term opioid use were identified: very low use (75.4%), low use (16.6%), moderate decreasing to low use (2.6%), low increasing to moderate use (2.6%), and sustained use (2.8%). Compared with individuals in the very low use trajectory group, those in the sustained use trajectory group were older (age ≥65 years: 22.0% vs 58.4%); had more comorbidities, including cancer (4.1% vs 22.2%); had increased health services contact, including hospital admissions (36.9% vs 51.6%); had higher use of psychotropic (16.4% vs 42.4%) and other analgesic drugs (22.9% vs 47.3%) prior to opioid initiation, and were initiated on stronger opioids (20.0% vs 50.2%).

Conclusions and relevance

Results of this cohort study suggest that most individuals commencing treatment with prescription opioids had relatively low and time-limited exposure to opioids over a 5-year period. The small proportion of individuals with sustained or increasing use was older with more comorbidities and use of psychotropic and other analgesic drugs, likely reflecting a higher prevalence of pain and treatment needs in these individuals.

Quality of life in patients with fibromyalgia: Contributions of disease symptoms, lifestyle and multi-medication

Fibromyalgia (FM) is a disease characterized by the presence of chronic and widespread musculoskeletal pain, which causes a high negative impact on the quality of life (QoL). Although there are many studies about the QoL of patients with FM, it is unknown which variables have a main influence on it. Therefore, in the present study, we aimed to determine which FM symptoms predict a worse QoL and also to establish whether lifestyle and multi-medication are associated to QoL. We assessed a sample of 134 women with FM using a semi-structured clinical interview to explore lifestyle (diet, exercise, smoking) and medication use, and questionnaires to cover the main symptoms of this disease and QoL (SF-36). We found that the patients with FM had a poor QoL, being “physical pain” and “vitality” the most affected domains. A linear regression analysis showed that depression and anxiety assessed by HADS were the FM symptoms which most significantly predicted QoL, explaining 49% of the variance. Concerning lifestyle/medication influences, we found that multiple drug treatment and smoking also predicted a worse QoL (14%). Moreover, patients who practiced exercise regularly showed better QoL than patients who did not (regardless of the severity of FM). Thus, our results suggest that treatment strategies to improve QoL in FM should be focused on improving psychological distress, promoting regular exercise and reducing smoking and multi-medication. The data highlights the role of positive self-management practices to improve QoL in FM.

Predictors of older adults' chronic pain in the context of opioid adverse drug events

BACKGROUND

Factors predictive of chronic pain in older adults could help focus prevention and treatment efforts for those most at risk of chronic pain.

PURPOSE

The objective of the study was to describe demographic and pain self-management factors predictive of chronic pain in the context of opioid adverse drug events (ADEs) reported for a cohort of older adults within the same year.

METHOD

The design was a post hoc analysis of 9,095 cases aged 65 years and older from the 2019 National Health Interview Survey that reported chronic pain and 380 cases aged 65 years and older with opioid adverse events reported to the Food and Drug Administration Adverse Event Reporting System (FAERS) during the second quarter of 2019. Logistic regression predicted chronic pain.

RESULTS

Less than a baccalaureate education increased the odds of chronic pain by 28.0% while lower income minimally increased the odds. Male gender increased the odds of chronic pain by 12.0%. Increased age minimally increased the odds for chronic pain. Use of opioids, other pain treatments, complementary treatments, and antidepressants were all associated with increased odds of chronic pain. FAERS opioid ADEs ranged from pruritus to death, with death identified in 16 (4.2%) cases. Misuse, abuse, or dependence was documented in 1.8% of cases.

CONCLUSIONS AND IMPLICATIONS

Less-educated older adults may be particularly at risk of chronic pain and should be routinely assessed and prescribed safe and efficacious pain self-management as needed. Some men may need additional support to use pain treatments.

Use of pharmacological and nonpharmacological treatments for chronic noncancer pain among people using opioids: a longitudinal cohort study

ABSTRACT

Although multimodal management of chronic noncancer pain (CNCP) is recommended, long-term treatment utilization patterns among people using opioids are not well known. The Pain and Opioids IN Treatment study recruited Australian adults receiving opioids for CNCP for more than 6 weeks from community pharmacies. Pharmacological (opioid and nonopioid analgesics and psychotropic medicines) and nonpharmacological (physical, mental health, and specialized) treatments used in the previous 12 months and 30 days were collected annually over 4 years (2015-2018). Associations were explored between 30-day treatment use and sociodemographic characteristics and pain measures. Overall, 1334 participants completed at least one annual follow-up. The median pain severity (5.0, interquartile range [IQR] 3.8 to 6.3) and pain interference scores (5.7, IQR 3.9-7.3) indicated moderate pain throughout the study period, despite most participants reporting the use of nonopioid pharmacological (12 month: 97.6% and 30 day: 96.8%) and nonpharmacological treatments (12 month: 91.8% and 30 day: 66.1%). Some treatment use was inconsistent with guidelines: ongoing nonsteroidal anti-inflammatory drugs and sedative-hypnotic use were common, whereas fewer people engaged with pain management programs (12 month: 22.3%). Private health insurance was associated with using physical (adjusted odds ratio 1.61, 99.5% confidence intervals 1.15-2.24) and specialized nonpharmacological treatments (adjusted odds ratio 1.47, 99.5% confidence intervals 1.14-1.91). This study demonstrates that many Australians taking opioids long-term for CNCP also use nonopioid pharmacological and nonpharmacological treatments. The use of pharmacological treatments including nonsteroidal anti-inflammatory drugs, psychotropic medicines, and gabapentinoids, outside guidelines, warrants review. Furthermore, despite Australia's universal healthcare scheme subsidising some nonpharmacological treatments, overall use of these treatments was associated with having private health insurance, highlighting a need for more equitable service provision.

Risk of Overdose Associated With Co-prescription of Antipsychotics and Opioids: A Population-Based Cohort Study

The US FDA issued a black-box warning against co-prescription of antipsychotic (AP) agents and opioids due to the risk of respiratory depression, but evidence on the comparative safety of sedating vs nonsedating APs is lacking. We classified APs as sedating (eg, quetiapine, olanzapine, and chlorpromazine) and nonsedating (eg, aripiprazole, haloperidol, and risperidone) based on their affinity to the histamine-1 neuroreceptor (Ki < or ≥20, respectively) and sought to compare the rate of overdose between patients using sedating vs nonsedating APs plus opioids. We constructed a population-based cohort nested in the IBM MarketScan database (2004-2017). Patients with concomitant use of sedating APs and prescription opioids ("exposed") were 1:1 matched to patients with concomitant use of nonsedating APs and prescription opioids ("referent") based on the propensity score (PS). The primary outcome was any hospitalization or emergency department visit due to an overdose within 30 days. The final cohort comprised 62 604 exposed and an equal number of PS-matched reference patients. Characteristics of matched exposed and reference patients were similar. There were 178 overdose events among the exposed (35.3 events per 1000 person-years [PY]) vs 133 among the reference group (26.4 events per 1000 PY), for an adjusted hazard ratio of 1.34 (95% CI: 1.07-1.68). This finding was consistent across sensitivity and subgroup analyses. Among patients receiving prescription opioids, concomitant use of sedating APs was associated with an increased risk of overdose compared with nonsedating APs. Caution is required when co-prescribing opioids and APs. If co-prescription is needed, choosing a nonsedating agent should be preferred whenever possible given the clinical context.

Antidepressant and anticonvulsant prescription rates in patients with osteoarthritis: a population-based cohort study

Objectives

There are signs that antidepressants and anticonvulsants are being prescribed more often for OA patients, despite limited evidence. Our objectives were to examine prescription rates and time trends for antidepressants and anticonvulsants in OA patients, to assess the percentage of long-term prescriptions, and to determine patient characteristics associated with antidepressant or anticonvulsant prescription.

Methods

A population-based cohort study was conducted using the Integrated Primary Care Information database. First, episodic and prevalent prescription rates for antidepressants (amitriptyline, nortriptyline and duloxetine) and anticonvulsants (gabapentinoids) in OA patients were calculated for the period 2008–17. Logistic regression was used to assess which patient characteristics were associated with prescriptions.

Results

In total, 164 292 OA patients were included. The prescription rates of amitriptyline, gabapentin and pregabalin increased over time. The increase in prescription rates for pregabalin was most pronounced. Episodic prescription rate increased from 7.1 to 13.9 per 1000 person-years between 2008 and 2017. Amitriptyline was prescribed most (15.1 episodic prescriptions per 1000 person-years in 2017). Prescription rates of nortriptyline and duloxetine remained stable at 3.0 and 2.0 episodic prescriptions per 1000 person-years, respectively. For ≤3% of patients with incident OA, medication was prescribed long-term (≥3 months). In general, all medication was prescribed more frequently for older patients (except duloxetine), women, patients with OA in ≥2 joints, patients with spinal OA and patients with musculoskeletal disorders.

Conclusion

Prescription rates of amitriptyline, gabapentin and pregabalin increased over time. Since there is little evidence to support prescription in OA, caution is necessary when prescribing.

A Systematic Review and Meta-Analysis of Cognitive Performance among People with Chronic Use of Opioids for Chronic Non-Cancer Pain

OBJECTIVE

Opioids, often prescribed for chronic non-cancer pain, may adversely affect cognition. Research has not been synthesized in recent years, during which time academic interest has increased. This study presents meta-analyses on cognitive performance in people taking opioids for chronic non-cancer pain (CNCP).

METHODS

We ran systematic literature searches in EMBASE, Medline, and PsycINFO. Eligible studies included people taking opioids for CNCP, an opioid-free group (i.e., case-control) or session (e.g., pre-post), and objective cognitive assessments. Using random-effects meta-analyses, we computed pooled effect sizes for differential task performance for each study design across five domains (motor performance, attention, working memory, executive functions, memory).

RESULTS

Seventeen studies were included. Case-control studies covered three control types (healthy, CNCP, taper-off). Pre-post studies were grouped into five follow-ups (four to six and six to nine weeks; three, six, and 12 months). Effect sizes ranged from 0.02-0.62. Cases showed small magnitude impairments in attention and memory compared with healthy controls. Although limited by small sample sizes, there was no clear evidence of impairment in cases compared with opioid-free controls with CNCP. Cases showed some cognitive improvements from opioid-free baseline to follow-up. Effects were strongest for attention and working memory and were apparent from four weeks to six months follow-up. Other effects were small and nonsignificant.

CONCLUSIONS

Opioid therapy for CNCP did not worsen cognitive performance and improved it for some domains. People who take opioids for CNCP may evidence deficits in attention and memory, but this is unlikely to translate to global impairment and likely relates to pain more so than opioids.

Long-term postoperative opioid prescription after cholecystectomy or gastric by-pass surgery: a retrospective observational study

OBJECTIVES

Opioids are commonly prescribed post-surgery. We investigated the proportion of patients who were prescribed any opioids 6-12 months after two common surgeries - laparoscopic cholecystectomy and gastric by-pass (GBP) surgery. A secondary aim was to examine risk factors prior to surgery associated with the prescription of any opioids after surgery.

METHODS

We performed a retrospective observational study on data from medical records from patients who underwent cholecystectomy (n=297) or GBP (n=93) in 2018 in the Region of Västerbotten, Sweden. Data on prescriptions for opioids and other drugs were collected from the patients` medical records.

RESULTS

There were 109 patients (28%) who were prescribed opioids after discharge from surgery but only 20 patients (5%) who still received opioid prescriptions 6-12 months after surgery. All 20 of these patients had also been prescribed opioids within three months before surgery, most commonly for back and joint pain. Only 1 out of 56 patients who were prescribed opioids preoperatively due to gallbladder pain still received prescriptions for opioids 6-12 months after surgery. Although opioid use in the early postoperative period was more common among patients who underwent cholecystectomy, the patients who underwent GBP were more prone to be "long-term" users of opioids. In the patients who were prescribed opioids within three months prior to surgery, 8 out of 13 patients who underwent GBP and 12 of the 96 patients who underwent cholecystectomy were still prescribed opioids 6-12 months after surgery (OR 11.2; 95% CI 3.1-39.9, p=0,0002). Affective disorders were common among "long-term" users of opioids and prior benzodiazepine and amitriptyline use were significantly associated with "long-term" opioid use.

CONCLUSIONS

The proportion of patients that used opioids 6-12 months after cholecystectomy or GBP was low. Patients with preoperative opioid-use experienced a significantly higher risk of "long-term" opioid use when undergoing GBP compared to cholecystectomy. The indication for being prescribed opioids in the "long-term" were mostly unrelated to surgery. No patient who was naïve to opioids prior surgery was prescribed opioids 6-12 months after surgery. Although opioids are commonly prescribed in the preoperative and in the early postoperative period to patients with gallbladder disease, there is a low risk that these prescriptions will lead to long-term opioid use. The reasons for being prescribed opioids in the long-term are often due to causes not related to surgery.

Development of a Brief Patient-Administered Screening Tool for Prescription Opioid Dependence for Primary Care Settings

OBJECTIVE

To develop a short, patient-administered screening tool that will allow for earlier assessment of prescription opioid dependence (often referred to as addiction) in primary care settings.

DESIGN AND SETTING

Cross-sectional analysis (N = 1,134) from the two-year time point of the Pain and Opioids IN Treatment (POINT) cohort was used in the scale development.

SUBJECTS

Participants who completed two-year interviews in the POINT study, a prospective cohort study that followed people with chronic noncancer pain over a five-year period, and who were prescribed strong opioids for a minimum of six weeks at baseline.

METHODS

An advisory committee provided advice on wording and content for screening in primary care settings. Univariate logistic regression identified individual items that were significantly associated with meeting ICD-11 criteria for prescription opioid dependence. Exploratory and confirmatory factor analysis (EFA and CFA) were conducted, and items were reduced to identify a small item set that were discriminative and shared a simple underlying structure.

RESULTS

Sixty-four variables associated with ICD-11 criteria for prescription opioid dependence were initially identified. Four rounds of EFA were performed, resulting in five items remaining. CFA identified two possible four-item combinations, with the final combination chosen based on greater item endorsement and the results of goodness-of-fit indices.

CONCLUSIONS

Addressing prescription opioid dependence is an important part of the global public health challenge surrounding rising opioid-related harm. This study addresses an important initial requisite step to develop a brief screening tool. Further studies are required to validate the tool in clinical settings.

Mechanisms for Reducing Neuropathic Pain

Injury typically results in the development of neuropathic pain, but the pain normally decreases and disappears in paralleled with wound healing. The pain results from cells resident at, and recruited to, the injury site releasing pro-inflammatory cytokines and other mediators leading to the development of pro-inflammatory environment and causing nociceptive neurons to develop chronic ectopic electrical activity, which underlies neuropathic pain. The pain decreases as some of the cells that induce pro-inflammation, changing their phenotype leading to the blocking the release of pro-inflammatory mediators while releasing anti-inflammatory mediators, and blocking nociceptive neuron chronic spontaneous electrical activity. Often, despite apparent wound healing, the neuropathic pain becomes chronic. This raises the question of how chronic pain can be eliminated. While many of the cells and mediators contributing to the development and maintenance of neuropathic pain are known, a better understanding is required of how the injury site environment can be controlled to permanently eliminate the pro-inflammatory environment and silence the chronically electrically active nociceptive neurons. This paper examines how methods that can promote the transition of the pro-inflammatory injury site to an anti-inflammatory state, by changing the composition of local cell types, modifying the activity of pro- and anti-inflammatory receptors, inducing the release of anti-inflammatory mediators, and silencing the chronically electrically active nociceptive neurons. It also examines the hypothesis that factors released from platelet-rich plasma applied to chronic pain sites can permanently eliminate chronic inflammation and its associated chronic pain.