Postoperative Opioid Prescribing and New Persistent Opioid Use: The Risk of Excessive Prescribing

An automated group-housed oral fentanyl self-administration method in mice

RATIONALE AND OBJECTIVES

Social factors play a critical role in human drug addiction, and humans often consume drugs together with their peers. In contrast, in traditional animal models of addiction, rodents consume or self-administer the drug in their homecage or operant self-administration chambers while isolated from their peers. Here, we describe HOMECAGE ("Home-cage Observation and Measurement for Experimental Control and Analysis in a Group-housed Environment"), a translationally relevant method for studying oral opioid self-administration in mice. This setting reduces experimental confounds introduced by social isolation or interaction with the experimenter.

METHODS

We have developed HOMECAGE, a method in which mice are group-housed and individually monitored for their consumption of a drug vs. a reference liquid.

RESULTS

Mice in HOMECAGE preserve naturalistic aspects of behavior, including social interactions and circadian activity. The mice showed a preference for fentanyl and escalated their fentanyl intake over time. Mice preferred to consume fentanyl in bouts during the dark cycle. Mice entrained to the reinforcement schedule of the task, optimizing their pokes to obtain fentanyl rewards, and maintained responding for fentanyl under a progressive ratio schedule. HOMECAGE also enabled the detection of cage-specific and individual-specific behavior patterns and allowed the identification of differences in fentanyl consumption between co-housed control and experimental mice.

CONCLUSIONS

HOMECAGE serves as a valuable procedure for translationally relevant studies on oral opioid intake under conditions that more closely mimic the human condition. The method enables naturalistic investigation of factors contributing to opioid addiction-related behaviors and can be used to identify novel treatments.

Unveiling Prescribing Patterns: A Systematic Review of Chronic Opioid Prescriptions After Head and Neck Cancer Surgeries

OBJECTIVE

This study aims to review opioid prescribing changes for pain management in head and neck cancer (HNC) surgery patients, given the recent focus on Enhanced Recovery After Surgery protocols.

DATA SOURCES

MEDLINE, Embase, and CENTRAL, covering 1998 to 2023.

REVIEW METHODS

We selected studies that evaluated opioid prescribing patterns post-major HNC surgery in various settings, including tertiary care hospitals and community hospitals. Primary outcomes considered were prevalence and patterns of opioid use post-surgery, as well as related outcomes such as chronic use and side effects.

RESULTS

Of 1278 abstracts, 24 studies involving 17,027 patients from the United States, China, and Canada met inclusion criteria. Quality was assessed using the MINORS scale, with an average score of 9.9 for non-comparative studies and 20.0 for comparative studies. Persistent opioid use post-surgery, defined as ongoing prescriptions 90 days after treatment, was noted in 15.4% to 64% of patients. Two studies reported adverse events, with up to 16% of patients experiencing side effects. Risk factors for chronic use included preoperative opioid use, tobacco use, higher cancer stage, adjuvant treatment, and demographic factors. Correlations were found between larger opioid prescriptions and shorter survival in advanced cancers. There was notable variability in patient-reported pain control.

CONCLUSION

Persistent opioid use post-HNC surgery is common, with variable efficacy and risk of adverse effects. Tailoring pain management to individual risk factors and focusing on multimodal analgesia could reduce the risks of continued opioid use. Future prospective studies are required to identify optimal pain management strategies.

Exploring take-home opioid stewardship (ETHOS) in UK postoperative patients

Background

Surgery is one of the most common indications for a patient's first opioid prescription, with some patients progressing to unintended long-term use. There is no current data from the United Kingdom on how much patients use of the opioid medication dispensed at discharge from hospital. This study investigates discharge opioid prescribing and usage following common surgical procedures.

Methods

This cohort study was conducted at the Oxford University Hospitals NHS Foundation Trust and involved 20 of the most commonly performed adult surgical procedures. At least 20 patients per procedure were surveyed using a standardised telephone questionnaire 6-8 days after discharge to establish the amount of used and unused opioids. Opioid doses were converted to oral morphine equivalent (OME) for analysis.

Results

The amount of opioid given to patients after all types of surgery far exceeded requirement, with often large variations in prescribing practices for the same procedures, most notably in trauma and orthopaedics.For the cohort of 426 patients, a total of 55 080 mg OME was dispensed on discharge, with only 34.4% actually used by patients, leaving a total of 36 108.5 mg OME unused in the community, risking inappropriate opioid use, overdose, or diversion.

Conclusions

Opioid overprescribing is common after surgery and represents waste, expense, and risk to patients. There is a clear need to develop a procedure-specific evidence-base for discharge opioid prescribing, adopting an "enough but not too much" approach to ensure that patients have adequate analgesia to facilitate functional surgical recovery, but not more than is needed.

Creating a Framework for Minimizing Opioid Consumption after Office Based Surgery

PURPOSE OF REVIEW

Herein we review recent trends in opioid prescribing, the rise in office-based surgeries, and propose a framework to minimize opioid consumption following such procedures.

RECENT FINDINGS

Outpatient surgical procedures are increasing year over year in the United States. This observed increase is expected to continue due to the financial incentives to perform outpatient procedures. Office-based surgery is a setting that is expected to have tremendous growth. Still, currently there are scant safety guidelines concerning how to manage perioperative pain related to surgeries in this setting safely and effectively. Opioid abuse is rampant across the United States, and we anticipate that an increase in outpatient procedures will create a rise in opioid prescribing without appropriate discourse and planning. There are a variety of systematic factors in play to minimize opioid consumption after office-based surgery that must be considered at each operative phase. Careful planning and consideration of the multitude of factors can increase patient satisfaction while minimizing opioid prescriptions.

Opioid Prescriptions for US Patients Undergoing Long-Term Dialysis or with Kidney Transplant from 2011 to 2020

Key Points

The rate of prescription of opioid medication decreased between 2011 and 2020 for patients with ESRD. The risk of death for dialysis and kidney transplant patients increased as morphine milligram equivalents in prescriptions increased.

Background

Pain is important for patients with kidney failure, but opioid medication prescriptions are associated with morbidity and mortality. The Centers for Disease Control and Prevention issued opioid prescription guidelines in 2016 and 2022, associated with dramatically decreased prescription rates in the United States. It is critical to know whether nationwide opioid prescription rates for patients with kidney failure have decreased.

Methods

We analyzed the United States Renal Data System database from 2011 to 2020 to describe trends in the proportion of patients with ESKD who received one or more, or long-term, opioid prescriptions, examined factors associated with long-term opioid prescriptions, and evaluated associations of all-cause death with short-term or long-term opioid prescriptions.

Results

From 2011 to 2022, the percentage of patients with kidney failure (dialysis and kidney transplant) who received at least one or more, or who had received long-term, opioid medication prescriptions decreased steadily, from 60% to 42%, and from 23% to 13%, respectively (both P for trend < 0.001). The largest reductions in prescription rates were for hydrocodone and oxycodone. Similar trends existed for dialysis and kidney transplant patients. Women, the poor, and those in rural settings were more likely to receive long-term opioid prescriptions. Prescription rates were highest in White patients and those aged 45–64 years. Short-term and long-term opioid medication prescriptions were associated with higher mortality in both dialysis and kidney transplant patients.

Conclusions

The opioid prescription rates of patients with ESKD decreased between 2011 and 2020. Higher mortality risk was associated with both short-term and long-term opioid prescriptions. Mortality risk was monotonically associated with morphine milligram equivalents in patients with kidney failure who received long-term opioid prescriptions.

Open versus minimally invasive surgery: risk of new persistent opioid use

BACKGROUND

New persistent opioid use (NPOU) after surgery may represent a public health issue that adversely affects health outcomes and long-term patient survival. This study aimed to characterize the risk of NPOU relative to surgical approach among different operative procedures.

METHODS

Patients who underwent either open (open surgery [OS]) or minimally invasive (minimally invasive surgery [MIS]) pneumonectomy, pancreatectomy, and colectomy between 2013 and 2020 were identified from the IBM MarketScan database. NPOU was defined as 2 subsequent opioid refills within the first 90-day period, as well as in the following 91- to 180-day period after surgery among opioid-naive patients. Multivariate logistic regression was used to characterize the association between the surgical approach and the risk of NPOU.

RESULTS

Among 45,757 patients who underwent surgery (pneumonectomy: 7.6%; pancreatectomy: 7.1%; colectomy: 85.3%), median age was 54 years (IQR, 48-60). Most individuals were female (51.5%) and had a malignant indication (67.3%) for surgery. Overall, 50.7% of patients underwent OS, whereas 49.3% of patients underwent MIS. Subsequently, 4.8% of patients developed NPOU. The likelihood of NPOU was higher among patients who underwent OS than among individuals who underwent MIS (5.9% vs 3.6%, respectively; P < .001). Patients who underwent OS had higher 6-month total milligram equivalent doses (OS: 250 [IQR, 135-600] vs MIS: 200 [IQR, 100-421]) and days of opioid use (OS: 7 [IQR, 3-15] vs MIS: 5 [IQR, 3-10]) (both P < .001). Relative to OS, MIS was associated with 35% lower odds of NPOU (0.65; 95% CI, 0.59-0.71).

CONCLUSION

1 in 20 patients who underwent surgery experienced NPOU. MIS was associated with fewer days of opioid use and lower dosages, which translated into lower NPOU after surgery.

Characterizing patterns of opioid prescribing after outpatient ventral hernia repair with mesh

PURPOSE

Despite efforts to minimize opioid prescribing, outpatient ventral hernia repair (VHR) with mesh remains notoriously painful, often requiring postoperative opioid analgesia. Here, we aim to characterize patterns of opioid prescribing for the heterogenous group of patients and procedures that comprise mesh-based, outpatient VHR.

METHODS

The Abdominal Core Health Quality Collaborative registry was queried for patients undergoing VHR with mesh who were discharged the same or next day between January 2019 to October 2023. Procedures were broadly classified by approach and mesh location: open, minimally-invasive with intraperitoneal mesh (MIP), and minimally-invasive with retromuscular or preperitoneal mesh (MRPP). Surgeon-reported opioid prescription quantity and patient-reported 30-day consumption data were reviewed.

RESULTS

Of 2,795 patients who met inclusion criteria (46.1% open, 22.7% MIP, 31.2% MRPP), approximately 80% of patients consumed ≤ 10 tablets of opioid pain medication (open 87.7%, MIP 78.4%, MRPP 84.2%). For patients who were prescribed ≤ 10 tablets, the median number of unconsumed tablets was 5 (IQR 0-8). For patients who were prescribed > 10 tablets, the median number of unconsumed tablets was 10 or more (open 10 [IQR 2-16], MIP 10 [IQR 2-18], MRPP 12 [IQR 5-16]). The number of tablets consumed was positively correlated with the number of tablets prescribed (Kendall's rank correlation = 0.232, p < 0.001).

CONCLUSION

Regardless of technique, for outpatient VHR with mesh, the fewer opioid tablets prescribed, the fewer tablets patients consumed. Decreasing the prescription quantity to ≤ 10 tablets, coupled with preoperative patient education, may help minimize excess opioid prescribing while still achieving adequate pain control.

Opioid consumption in the first 30 days after surgery was independently associated with new persistent opioid use

INTRODUCTION

Previous studies suggest that new persistent opioid use (NPOU) after surgery was associated with larger perioperative opioid prescriptions, but the association between NPOU and postoperative opioid consumption is unknown.

METHODS

This retrospective study included opioid naïve individuals aged 18-64 who underwent surgical procedures across 70 Michigan hospitals between July 1, 2018 and November 15, 2021 and were prescribed opioids at discharge. We used clinical and patient-reported opioid consumption data from the Michigan Surgical Quality Collaborative, a statewide surgical registry, linked with the state Prescription Drug Monitoring Program. Multivariable logistic regression modeling was used to assess the association between patient-reported opioid consumption during the 30 days after discharge and NPOU, defined as having an opioid fill during both 31-120 days and 121-210 days after discharge.

RESULTS

Among 36,271 patients included, 482 (1.3%) developed NPOU. These patients consumed more opioid pills in the first 30 days postoperatively than those without NPOU (mean (SD): 7.3 (8.4) 5 mg oxycodone equivalent pills vs 4.1 (5.5), SMD=-0.41). In adjusted analyses, each additional opioid pill consumed in the 30-day postoperative period was associated with a 0.05 percentage-point increase in the predicted probability of NPOU (95% CI 0.04 to 0.07 percentage points). Thus, holding all other variables constant, a 10-pill increase in consumption would be associated with a 0.5 percentage-point increase in the probability of NPOU, or a 38.4% increase relative to the baseline rate of 1.3%.

CONCLUSION

Demonstrating that opioid consumption in the first 30 days after surgery was independently associated with NPOU underscores the importance of perioperative opioid prescribing on long-term outcomes.

A retrospective analysis of perioperative medications for opioid-use disorder and tapering additional postsurgical opioids via a transitional pain service

AIMS

To investigate perioperative opioid requirements in patients on methadone or buprenorphine as medication for opioid-use disorder (MOUD) who attended a transitional pain clinic (Personalized Pain Program, PPP).

METHODS

This retrospective cohort study assessed adults on MOUD with surgery and attendance at the Johns Hopkins PPP between 2017 and 2022. Daily non-MOUD opioid use over 6 time-points was evaluated with regression models controlling for days since surgery. The time to complete non-MOUD opioid taper was analysed by accelerated failure time and Kaplan-Meier models.

RESULTS

Fifty patients (28 on methadone, 22 on buprenorphine) were included with a median age of 44.3 years, 54% male, 62% Caucasian and 54% unemployed. MOUD inpatient administration occurred in 92.8% of patients on preoperative methadone but only in 36.3% of patients on preoperative buprenorphine. Non-MOUD opioid use decreased over time postoperatively (β = -0.54, P < .001) with a median decrease of 90 mg morphine equivalents (MME) between the first and last PPP visit, resulting in 46% tapered off by PPP completion. Older age and duration in PPP were associated with lower MME, while mental health conditions, longer hospital stays and higher discharge opioid prescriptions were associated with higher MME. The average time to non-MOUD opioid taper was 1.79× longer in patients on buprenorphine (P = .026), 2.75× in males (P = .023), 4.66× with mental health conditions (P < .001), 2.37× with chronic pain (P = .031) and 3.51× if on preoperative non-MOUD opioids; however, higher initial MOUD level decreased time to taper (P = .001).

CONCLUSIONS

Postoperative opioid tapering utilizing a transitional pain service is possible in patients on MOUD.

Persistent and chronic opioid use after ambulatory surgery in US veterans (2011-2018)

BACKGROUND

Opioid use beyond the perioperative period is a recognized adverse outcome, primarily studied in inpatients after complex major surgeries. Our goals are to determine the risk after ambulatory surgery and identify risk factors associated with long-term opioid prescriptions.

METHODS

Our ambulatory surgery cohort included 1,393,332 veterans from October 1, 2011, to September 30, 2018 (fiscal year [FY] 12-18). Data included age, sex, race, rurality of patient residence and facility, body mass index, tobacco use, Charlson Comorbidity Index, psychiatric disorder, pain score at surgery, substance use, and medications (benzodiazepine, tricyclics and/or selective serotonin reuptake inhibitor and opioids in the 12 months previous).

RESULTS

In aggregate, 9.6% had 1 or more prescriptions in the 90-180 days after surgery ("Persistent prescription[s]") and 1.8% had more than 180 days of opioids in the 31-366 days after surgery ("Chronic prescriptions"). For persistent prescription(s), trends over time decreased from 12.5% in FY12 to 7.1% by FY18 (P < .001). Similarly chronic prescriptions decreased from 2.9% in FY12 to 0.8% in FY18 (P < .001). The strongest independent association for persistent and chronic prescriptions after ambulatory surgery was previous prescription opioids, with 2.8 times increased risk for persistent prescriptions (adjusted odds ratio, 2.8; 95% confidence interval, 2.8-2.9; P < .001) and 3.3 times increased risk for chronic opioid prescriptions (adjusted odds ratio, 3.3; 95% confidence interval, 3.2-3.4; P < .001).

CONCLUSIONS

Rates of persistent and chronic opioid prescriptions after ambulatory surgery in the Veterans Health Administration are small and decreasing over time. Providers and patients should have informed discussions regarding risks of opioid postoperative pain management strategies.

Persistent Opioid Use After Hospital Admission From Surgery in New Zealand: A Population-Based Study

BACKGROUND

Persistent opioid use (POU) is common after surgery and is associated with an increased risk of mortality and morbidity. There have been no population-based studies exploring POU in opioid-naïve surgical patients in New Zealand (NZ). This study aimed to determine the incidence and risk factors for POU in opioid-naïve patients undergoing surgery in all NZ hospitals.

METHOD

We included all opioid-naïve patients who underwent surgery without a concomitant trauma diagnosis and received opioids after discharge from any NZ hospital between January 2007 and December 2019. Patients were considered opioid naïve if no opioids had been dispensed to them or if they did not have a prior diagnosis of an opioid-use disorder up to 365 days preceding the index date. The primary outcome was the incidence of POU, defined a priori as opioid use after discharge between 91 and 365 days. We used a multivariable logistic regression to identify risk factors for POU.

RESULTS

We identified 1789,407 patients undergoing surgery with no concomitant diagnosis of trauma; 377,144 (21.1%) were dispensed opioids and 260,726 patients were eligible and included in the analysis. Of those included in the final sample, 23,656 (9.1%; 95% confidence interval [CI], 9.0%-9.2%) developed POU. Risk factors related to how opioids were prescribed included: changing to different opioid(s) after discharge (adjusted odds ratio [aOR], 3.21; 95% CI, 3.04-3.38), receiving multiple opioids on discharge (aOR, 1.37; 95% CI, 1.29-1.45), and higher total oral morphine equivalents (>400 mg) (aOR, 1.23; 95% CI, 1.23-1.45). Conversely, patients who were coprescribed nonopioid analgesics on discharge had lower odds of POU (aOR, 0.91; 95% CI, 0.87-0.95). Only small differences were observed between different ethnicities. Other risk factors associated with increased risk of POU included undergoing neurosurgery (aOR, 2.02; 95% CI, 1.83-2.24), higher comorbidity burden (aOR, 1.90; 95% CI, 1.75-2.07), preoperative nonopioid analgesic use (aOR, 1.65; 95% CI, 1.60-1.71), smoking (aOR, 1.44; 95% CI, 1.35-1.54), and preoperative hypnotics use (aOR, 1.35; 95% CI, 1.28-1.42).

CONCLUSIONS

Approximately 1 in 11 opioid-naïve patients who were dispensed opioids on surgical discharge, developed POU. Potentially modifiable risk factors for POU, related to how opioids were prescribed included changing opioids after discharge, receiving multiple opioids, and higher total dose of opioids given on discharge. Clinicians should discuss the possibility of developing POU with patients before and after surgery and consider potentially modifiable risk factors for POU when prescribing analgesia on discharge after surgery.

Long-term Health Outcomes of New Persistent Opioid Use After Gastrointestinal Cancer Surgery

BACKGROUND

New persistent opioid use (NPOU) after surgery has been identified as a common complication. This study sought to assess the long-term health outcomes among patients who experienced NPOU after gastrointestinal (GI) cancer surgery.

METHODS

Patients who underwent surgery for hepato-pancreato-biliary and colorectal cancer between 2007 and 2019 were identified using the Surveillance, Epidemiology, and End Results (SEER)-Medicare-linked database. Mixed-effect multivariable logistic regression and Cox proportional hazard models were used to estimate the risk of mortality and hospital visits related to falls, respiratory events, or pain symptoms.

RESULTS

Among 15,456 patients who underwent GI cancer surgery, 967(6.6%) experienced NPOU. Notably, the patients at risk for the development of NPOU were those with a history of substance abuse (odds ratio [OR], 1.45; 95% confidence interval [CI], 1.14-1.84), moderate social vulnerability (OR, 1.26; 95% CI, 1.06-1.50), an advanced disease stage (OR, 4.42; 95% CI, 3.51-5.82), or perioperative opioid use (OR, 3.07; 95% CI, 2.59-3.63. After control for competing risk factors, patients who experienced NPOU were more likely to visit a hospital for falls, respiratory events, or pain symptoms (OR, 1.45, 95% CI 1.18-1.78). Moreover, patients who experienced NPOU had a greater risk of death at 1 year (hazard ratio [HR], 2.15; 95% CI, 1.74-2.66).

CONCLUSION

Approximately 1 in 15 patients experienced NPOU after GI cancer surgery. NPOU was associated with an increased risk of subsequent hospital visits and higher mortality. Targeted interventions for individuals at higher risk for NPOU after surgery should be used to help mitigate the harmful effects of NPOU.

Evaluation of an Opioid-free Pathway for Perineal Reconstructive Surgery: A 1-year Pilot Study

OBJECTIVE

To evaluate the impact of a standardized perioperative pain management pathway on postoperative opioid prescribing practices following male perineal reconstructive surgery at our institution.

METHODS

Patients undergoing perineal reconstructive surgery (urethroplasty, artificial urinary sphincter, urethral sling) by a single surgeon from July 2022 to June 2023 were prospectively followed. A standardized nonopioid pathway was implemented in the perioperative period. Intraoperative local anesthetic included liposomal bupivacaine mixed with 0.25% bupivacaine. Opioids are administered in the recovery room at the discretion of anesthesiology providers. As of July 2022, our standard practice does not include a postoperative opioid prescription unless pain is poorly controlled in the recovery area. Postoperative communication encounters and opioid prescriptions were tracked through the electronic health record (EHR) in order to assess the efficacy of an opioid-free pathway.

RESULTS

Sixty-seven patients met the criteria during the study period, 64/67 performed in an outpatient setting. 6/67 (9%) patients were prescribed an opioid postoperatively; 4 related to post-surgical pain, and 2 related to chronic pain. No refills were prescribed. Of the 26 patients who received an opioid in the recovery area, 2 (7.6%) were prescribed an opioid at discharge. 15/67 (22%) patients had a communication encounter related to pain within 30 days, most commonly related to bladder spasm management. Only 2 of these encounters resulted in an electronic opioid prescription.

CONCLUSION

An opioid-free pathway is appropriate for opioid naive men undergoing perineal reconstructive surgery. When necessary, electronic opioid prescribing should be employed following discharge for breakthrough pain.

Opioid consumption before discharge predicts outpatient opioid use in adolescents undergoing surgery

BACKGROUND

The majority of adolescents undergoing surgery report unused prescription opioids after surgery, increasing the risk of diversion, misuse, and addiction. Adult studies have demonstrated that opioid use 24 hours before discharge corresponds with opioid use at home. We hypothesized that inpatient opioid consumption is associated with outpatient opioid use in adolescents.

METHODS

Adolescents aged 13-20 years undergoing elective surgery associated with an opioid prescription were prospectively recruited. Parent-adolescent dyads were surveyed preoperatively to assess sociodemographics, health literacy, and baseline substance use, and opioid use was measured at 30- and 90-days postoperatively. Medical records were reviewed to calculate cumulative opioid use during hospitalization. Inpatient and postoperative opioid use was converted to oral morphine equivalents. Adjusting for age, sex, race, health literacy, alcohol use, pain score, and surgery, multivariable linear regression identified factors associated with outpatient oral morphine equivalent use 90 days postoperatively.

RESULTS

Overall, 103 adolescents were enrolled. Median oral morphine equivalents used from 24 and 48 hours before discharge and throughout the hospitalization were 30.8 (interquartile range:11.7-45.0), 67.5 (interquartile range:37.5-94.3), and 97.5 (interquartile range:18.0-152.7), respectively. Regression analysis demonstrated that adolescent-reported pain at discharge (P = .028) and cumulative oral morphine equivalents used 24 hours (P < .001) and 48 hours (P = .003) before discharge were significantly associated with postoperative oral morphine equivalents use at home. Oral morphine equivalents consumption 24 hours before discharge estimated cumulative oral morphine equivalents use 90 days postoperatively at a 1-to-5 ratio in 94.1% of patients.

CONCLUSION

For adolescents undergoing surgery, patient-reported pain at discharge and oral morphine equivalents administered 24 hours before discharge are associated with cumulative outpatient opioid use. Tailoring outpatient prescriptions to total oral morphine equivalent consumption 24 hours before discharge could reduce excess opioid prescribing.

Experiences and perspectives of adults on using opioids for pain management in the postoperative period: A scoping review

BACKGROUND

Opioids play an important role in peri-operative pain management. However, opioid use is challenging for healthcare practitioners and patients because of concerns related to opioid crises, addiction and side effects.

OBJECTIVE

This review aimed to identify and synthesise the existing evidence related to adults' experiences of opioid use in postoperative pain management.

DESIGN

Systematic scoping review of qualitative studies. Inductive content analysis and the Theoretical Domains Framework (TDF) were applied to analyse and report the findings and to identify unexplored gaps in the literature.

DATA SOURCES

Ovid MEDLINE, PsycInfo, Embase, CINAHL (EBSCO), Cochrane Library and Google Scholar.

ELIGIBILITY CRITERIA

All qualitative and mixed-method studies, in English, that not only used a qualitative approach that explored adults' opinions or concerns about opioids and/or opioid reduction, and adults' experience related to opioid use for postoperative pain control, including satisfaction, but also aspects of overall quality of a person's life (physical, mental and social well being).

RESULTS

Ten studies were included; nine were qualitative ( n  = 9) and one used mixed methods. The studies were primarily conducted in Europe and North America. Concerns about opioid dependence, adverse effects, stigmatisation, gender roles, trust and shared decision-making between clinicians and patients appeared repeatedly throughout the studies. The TDF analysis showed that many peri-operative factors formed people's perceptions and experiences of opioids, driven by the following eight domains: Knowledge, Emotion, Beliefs about consequences, Beliefs about capabilities, Self-confidence, Environmental Context and Resources, Social influences and Decision Processes/Goals. Adults have diverse pain management goals, which can be categorised as proactive and positive goals, such as individualised pain management care, as well as avoidance goals, aimed at sidestepping issues such as addiction and opioid-related side effects.

CONCLUSION

It is desirable to understand the complexity of adults' experiences of pain management especially with opioid use and to support adults in achieving their pain management goals by implementing an individualised approach, effective communication and patient-clinician relationships. However, there is a dearth of studies that examine patients' experiences of postoperative opioid use and their involvement in opioid usage decision-making. A summary is provided regarding adults' experiences of peri-operative opioid use, which may inform future researchers, healthcare providers and guideline development by considering these factors when improving patient care and experiences.

The persistent benefits of decreasing default pill counts for postoperative narcotic prescriptions

BACKGROUND

In 2017, a university-based academic healthcare system changed the opioid default pill count from 30 to 12 pills. Modifying the electronic default pill count influences short-term clinician prescribing practices. We sought to understand the long-term impact on postoperative opioid prescribing habits after an opioid default pill count reduction.

MATERIALS AND METHODS

A retrospective electronic medical record system (EMRS) review was conducted in a healthcare system comprised of seven affiliated hospitals. Patients who underwent a surgical procedure and were prescribed an opioid on discharge between 2017-2021 were evaluated. All prescriptions were converted into morphine equivalents (MME). Analyses were performed with the chi-square test and Bonferonni adjusted t-test.

RESULTS

191,379 surgical procedures were studied. The average quantity of opioids prescribed decreased from 32 oxycodone 5 mg tablets in 2017 to 21 oxycodone 5 mg tablets in 2021 (236 MME to 154 MME, p<0.001). The percentage of patients obtaining a refill within 90 days of surgery varied between 18.3% and 19.9% (p<0.001). Patients with a pre-existing opioid prescription and opioid-naïve patients both had significant reductions in prescription quantities above the default MME (79.7% to 60.6% vs. 65.3% to 36.9%, p<0.001). There was no significant change in refills for both groups (pre-existing 36.7% to 38.3% (p = 0.1) vs naïve 15.0% to 15.3% (p = 0.29)).

CONCLUSIONS

The benefits of decreasing the default opioid pill count continue to accumulate long after the original change. Physician uptake of small changes to default EMRS practices represents a sustainable and effective intervention to reduce the quantities of postoperative opioids prescribed without deleterious effects on outpatient opiate requirements.

Epidemiology of Opioid Prescribing After Discharge From Surgical Procedures Among Adults

Importance

Opioid medications are commonly prescribed for the management of acute postoperative pain. In light of increasing awareness of the potential risks of opioid prescribing, data are needed to define the procedures and populations for which most opioid prescribing occurs.

Objective

To identify the surgical procedures accounting for the highest proportion of opioids dispensed to adults after surgery in the United States.

Design, Setting, and Participants

This cross-sectional analysis of the 2020-2021 Merative MarketScan Commercial and Multi-State Databases, which capture medical and pharmacy claims for 23 million and 14 million annual privately insured patients and Medicaid beneficiaries, respectively, included surgical procedures for individuals aged 18 to 64 years with a discharge date between December 1, 2020, and November 30, 2021. Procedures were identified using a novel crosswalk between 3664 Current Procedural Terminology codes and 1082 procedure types. Data analysis was conducted from November to December 2023.

Main Outcomes and Measures

The total amount of opioids dispensed within 3 days of discharge from surgery across all procedures in the sample, as measured in morphine milligram equivalents (MMEs), was calculated. The primary outcome was the proportion of total MMEs attributable to each procedure type, calculated separately among procedures for individuals aged 18 to 44 years and those aged 45 to 64 years.

Results

Among 1 040 934 surgical procedures performed (mean [SD] age of patients, 45.5 [13.3] years; 663 609 [63.7%] female patients), 457 016 (43.9%) occurred among individuals aged 18 to 44 years and 583 918 (56.1%) among individuals aged 45 to 64 years. Opioid prescriptions were dispensed for 503 058 procedures (48.3%). Among individuals aged 18 to 44 years, cesarean delivery accounted for the highest proportion of total MMEs dispensed after surgery (19.4% [11 418 658 of 58 825 364 MMEs]). Among individuals aged 45 to 64 years, 4 of the top 5 procedures were common orthopedic procedures (eg, arthroplasty of knee, 9.7% of total MMEs [5 885 305 of 60 591 564 MMEs]; arthroscopy of knee, 6.5% [3 912 616 MMEs]).

Conclusions and Relevance

In this cross-sectional study of the distribution of postoperative opioid prescribing in the United States, a small number of common procedures accounted for a large proportion of MMEs dispensed after surgery. These findings suggest that the optimal design and targeting of surgical opioid stewardship initiatives in adults undergoing surgery should focus on the procedures that account for the most opioid dispensed following surgery over the life span, such as childbirth and orthopedic procedures. Going forward, systems that provide periodic surveillance of opioid prescribing and associated harms can direct quality improvement initiatives to reduce opioid-related morbidity and mortality.

Association Between Opioid-Related Mortality and History of Surgical Procedure: A Population-Based Case-Control Study

Objective

This study examined whether there is an association between opioid-related mortality and surgical procedures.

Methods

A case-control study design using deceased controls compared individuals with and without opioid death and their exposure to common surgeries in the preceding 4 years. This population-based study used linked death and hospitalization databases in Canada (excluding Quebec) from January 01, 2008 to December 31, 2017. Cases of opioid death were identified and matched to 5 controls who died of other causes by age (±4 years), sex, province of death, and date of death (±1 year). Patients with HIV infection and alcohol-related deaths were excluded from the control group. Logistic regression was used to determine if there was an association between having surgery and death from an opioid-related cause by estimating the crude and adjusted odds ratios (ORs) with the corresponding 95% confidence interval (CI). Covariates included sociodemographic characteristics, comorbidities, and the number of days of hospitalization in the previous 4 years.

Results

We identified 11,865 cases and matched them with 59,345 controls. About 11.2% of cases and 12.5% of controls had surgery in the 4 years before their death, corresponding to a crude OR of 0.89 (95% CI: 0.83-0.94). After adjustment, opioid mortality was associated with surgical procedure with OR of 1.26 (95% CI: 1.17-1.36).

Conclusions

After adjusting for comorbidities, patients with opioid mortality were more likely to undergo surgical intervention within 4 years before their death. Clinicians should enhance screening for opioid use and risk factors when considering postoperative opioid prescribing.

Factors associated with use of opioid rescue medication after surgery

BACKGROUND

Opioid exposure after surgery increases risk of persistent opioid use. Here, we characterize at-home use of opioid rescue medication during 1-2 days after outpatient surgery (N=270) in a postoperative opioid-sparing context at a Norwegian hospital.

METHODS

The postsurgical pain management plan included non-steroidal anti-inflammatory drugs and up to six pills of 5 mg oxycodone as rescue analgesics. In this observational study we assessed risk factors for taking rescue opioids after surgery, by comparing patients who did, with those who did not.

RESULTS

Only 35% (N=228) of patients reported taking rescue opioids 1-2 days after discharge. Patients taking rescue opioids after surgery (opioid-takers) differed from non-takers by prevalence of preoperative chronic pain (>3 months; 74% vs 48%), higher pain severity and interference before and after surgery, reporting lower ability to cope with postsurgical pain, higher nervousness about the surgery, being younger, and having received more opioid analgesics in the recovery room. Exploratory predictive modeling identified opioid administration in the recovery room as the most important predictor of at-home rescue medication use. Follow-up after >4 months indicated low acute pain levels (mean±SD = 1.1±1.8), with only four patients (2%, N=217) reporting opioid analgesic use.

CONCLUSION

Factors related to at-home rescue medication use closely mirrored known risk factors for persistent opioid use after surgery, such as prior chronic pain, prior substance use, affective disturbances, and pain severity before surgery. These findings are potential targets in patient-centered care. Nevertheless, and reassuringly, findings are consistent with the idea that opioid-sparing postsurgical care can prevent large-scale chronic opioid use.

Persistent long-term opioid use after trauma: Incidence and risk factors

BACKGROUND

The opioid epidemic in the United States continues to lead to a substantial number of preventable deaths and disability. The development of opioid dependence has been strongly linked to previous opioid exposure. Trauma patients are at particular risk since opioids are frequently required to control pain after injury. The purpose to this study was to examine the prevalence of opioid use before and after injury and to identify risk factors for persistent long-term opioid use after trauma.

METHODS

Records for all patients admitted to a Level 1 trauma center over a 1-year period were analyzed. Demographics, injury characteristics, and hospital course were recorded. A multistate Prescription Drug Monitoring Program database was queried to obtain records of all controlled substances prescribed from 6 months before the date of injury to 12 months after hospital discharge. Patients still receiving narcotics at 1 year were defined as persistent long-term users and were compared against those who were not.

RESULTS

A total of 2,992 patients were analyzed. Of all patients, 20.4% had filled a narcotic prescription within the 6 months before injury, 53.5% received opioids at hospital discharge, and 12.5% had persistent long-term use after trauma with the majority demonstrating preinjury use. Univariate risk factors for long-term use included female sex, longer length of stay, higher Injury Severity Score, anxiety, depression, orthopedic surgeries, spine injuries, multiple surgical locations, discharge to acute inpatient rehab, and preinjury opioid use. On multivariate analysis, the only significant predictors of persistent long-term prescription opioid use were preinjury use and a much smaller effect associated with use at discharge.

CONCLUSION

During a sustained opioid epidemic, concerns and caution are warranted in the use of prescription narcotics for trauma patients. However, persistent long-term opioid use among opioid-naive patients is rare and difficult to predict after trauma.

LEVEL OF EVIDENCE

Prognostic and Epidemiological; Level III.

Perioperative Opioid-Related Harms: Opportunities to Minimize Risk

Although substantial attention has been given to opioid prescribing in the United States, opioid-related mortality continues to climb due to the rising incidence and prevalence of opioid use disorder. Perioperative care has an important role in the consideration of opioid prescribing and the care of individuals at risk for poor postoperative pain- and opioid-related outcomes. Opioids are effective for acute pain management and commonly prescribed for postoperative pain. However, failure to align prescribing with patient need can result in overprescribing and exacerbate the flow of unused opioids into communities. Conversely, underprescribing can result in the undertreatment of pain, complicating recovery and impairing well-being after surgery. Optimizing pain management can be particularly challenging for individuals who are previously exposed to opioids or have critical risk factors, including opioid use disorder. In this review, we will explore the role of perioperative care in the broader context of the opioid epidemic in the United States, and provide considerations for a multidisciplinary, comprehensive approach to perioperative pain management and optimal opioid stewardship.

Association Between Payer Type and Risk of Persistent Opioid Use After Surgery

OBJECTIVE

To assess whether the risk of persistent opioid use after surgery varies by payer type.

BACKGROUND

Persistent opioid use is associated with increased health care utilization and risk of opioid use disorder, opioid overdose, and mortality. Most research assessing the risk of persistent opioid use has focused on privately insured patients. Whether this risk varies by payer type is poorly understood.

METHODS

This cross-sectional analysis of the Michigan Surgical Quality Collaborative database examined adults aged 18 to 64 years undergoing surgical procedures across 70 hospitals between January 1, 2017 and October 31, 2019. The primary outcome was persistent opioid use, defined a priori as 1+ opioid prescription fulfillment at (1) an additional opioid prescription fulfillment after an initial postoperative fulfillment in the perioperative period or at least 1 fulfillment in the 4 to 90 days after discharge and (2) at least 1 opioid prescription fulfillment in the 91 to 180 days after discharge. The association between this outcome and payer type was evaluated using logistic regression, adjusting for patient and procedure characteristics.

RESULTS

Among 40,071 patients included, the mean age was 45.3 years (SD 12.3), 24,853 (62%) were female, 9430 (23.5%) were Medicaid-insured, 26,760 (66.8%) were privately insured, and 3889 (9.7%) were covered by other payer types. The rate of POU was 11.5% and 5.6% for Medicaid-insured and privately insured patients, respectively (average marginal effect for Medicaid: 2.9% (95% CI 2.3%-3.6%)).

CONCLUSIONS

Persistent opioid use remains common among individuals undergoing surgery and higher among patients with Medicaid insurance. Strategies to optimize postoperative recovery should focus on adequate pain management for all patients and consider tailored pathways for those at risk.

Preoperative Versus Perioperative Risk Factors for Delayed Pain and Opioid Cessation After Total Joint Arthroplasty: A Prospective Cohort Study

INTRODUCTION

The evolution of pre- versus postoperative risk factors remains unknown in the development of persistent postoperative pain and opioid use. We identified preoperative versus comprehensive perioperative models of delayed pain and opioid cessation after total joint arthroplasty including time-varying postoperative changes in emotional distress. We hypothesized that time-varying longitudinal measures of postoperative psychological distress, as well as pre- and postoperative use of opioids would be the most significant risk factors for both outcomes.

METHODS

A prospective cohort of 188 patients undergoing total hip or knee arthroplasty at Stanford Hospital completed baseline pain, opioid use, and emotional distress assessments. After surgery, a modified Brief Pain Inventory was assessed daily for 3 months, weekly thereafter up to 6 months, and monthly thereafter up to 1 year. Emotional distress and pain catastrophizing were assessed weekly to 6 months, then monthly thereafter. Stepwise multivariate time-varying Cox regression modeled preoperative variables alone, followed by all perioperative variables (before and after surgery) with time to postoperative opioid and pain cessation.

RESULTS

The median time to opioid and pain cessation was 54 and 152 days, respectively. Preoperative total daily oral morphine equivalent use (hazard ratio-HR 0.97; 95% confidence interval-CI 0.96-0.98) was significantly associated with delayed postoperative opioid cessation in the perioperative model. In contrast, time-varying postoperative factors: elevated PROMIS (Patient-Reported Outcomes Measurement Information System) depression scores (HR 0.92; 95% CI 0.87-0.98), and higher Pain Catastrophizing Scale scores (HR 0.85; 95% CI 0.75-0.97) were independently associated with delayed postoperative pain resolution in the perioperative model.

CONCLUSIONS

These findings highlight preoperative opioid use as a key determinant of delayed postoperative opioid cessation, while postoperative elevations in depressive symptoms and pain catastrophizing are associated with persistent pain after total joint arthroplasty providing the rationale for continued risk stratification before and after surgery to identify patients at highest risk for these distinct outcomes. Interventions targeting these perioperative risk factors may prevent prolonged postoperative pain and opioid use.

Opioid analgesic effects on subjective well-being in the operating theatre

Exposure to opioid analgesics due to surgery increases the risk of new persistent opioid use. A mechanistic hypothesis for opioids' abuse liability rests on the belief that, in addition to pain relief, acute opioid treatment improves well-being (e.g. via euphoria) and relieves anxiety. However, opioids do not consistently improve mood in laboratory studies of healthy non-opioid users. This observational study determined how two commonly used opioid analgesics affected patients' subjective well-being in standard clinical practice. Day surgery patients rated how good and how anxious they felt before and after an open-label infusion of remifentanil (n = 159) or oxycodone (n = 110) in the operating theatre before general anaesthesia. One minute after drug injection, patients reported feeling intoxicated (> 6/10 points). Anxiety was reduced after opioids, but this anxiolytic effect was modest (remifentanil Cohen's d = 0.21; oxycodone d = 0.31). There was moderate to strong evidence against a concurrent improvement in well-being (Bayes factors > 6). After remifentanil, ratings of 'feeling good' were significantly reduced from pre-drug ratings (d = 0.28). After oxycodone, one in three participants felt better than pre-drug. Exploratory ordered logistic regressions revealed a link between previous opioid exposure and opioid effects on well-being, as only 14 of the 80 opioid-naïve patients reported feeling better after opioid injection. The odds of improved well-being ratings after opioids were higher in patients with previous opioid exposure and highest in patients with > 2 weeks previous opioid use (adjusted OR = 4.4). These data suggest that opioid-induced improvement of well-being is infrequent in opioid-naïve patients. We speculate that peri-operative exposure could increase risk of persistent use by rendering subsequent positive opioid effects on well-being more likely.

Discharge of postoperative patients with an opioid prescription is associated with increased persistent opioid use, healthcare expenditures and mortality: a retrospective cohort study

BACKGROUND

The risk factors for persistent opioid use after surgical discharge and the association between opioid prescription at discharge and postoperative emergency department visits, readmission, and mortality are unclear.

METHODS

This population-based retrospective cohort study involved opioid-naive patients who underwent surgical procedures from January 1, 2000 to November 30, 2020. The data source was Hong Kong Hospital Authority Clinical Management System electronic health record. The primary outcome was the incidence of new persistent opioid use. Other study outcomes included 30-day emergency department visits, 30-day readmission, and 30-day all-cause mortality. Multivariable logistic regression models were used to estimate the association between opioid prescription at discharge and persistent opioid use, emergency department visits, readmission, and all-cause mortality.

RESULTS

Over a median follow-up of 1 month with 36 104 person-years, 438 128 patients (opioid prescription: 32 932, no opioid prescription: 405 196) who underwent surgical procedures were analysed, of whom 15 112 (3.45%) had persistent opioid use after discharge. Prescribing opioids on discharge was associated with increased risks of developing persistent opioid use (odds ratio [OR]: 2.30, 95% confidence interval [CI]: 2.19-2.40, P<0.001), 30-day emergency department visits (OR: 1.28, 95% CI: 1.23-1.33, P<0.001), 30-day readmission (OR: 1.17, 95% CI: 1.13-1.20, P<0.001), and 30-day all-cause mortality (OR: 1.68, 95% CI: 1.53-1.86, P<0.001).

CONCLUSIONS

In this large cohort of patients undergoing surgery, an opioid prescription on discharge was associated with a higher chance of persistent opioid use and increased risks of postoperative emergency department visits, readmission, and mortality. Minimising opioid prescriptions on discharge could improve perioperative patient outcomes.

Safety and Distribution of Opioid Prescribing by U.S. Surgeons

OBJECTIVE

To estimate high-risk prescribing patterns among opioid prescriptions from U.S. surgeons; to characterize the distribution of high-risk prescribing among surgeons.

BACKGROUND

National data on the prevalence of opioid prescribing and high-risk opioid prescribing by U.S. surgeons are lacking.

METHODS

Using the IQVIA Prescription Database, which reports dispensing from 92% of U.S. pharmacies, we identified opioid prescriptions from surgeons dispensed in 2019 to patients ages ≥12 years. "High-risk" prescriptions were characterized by: days supplied >7, daily dosage ≥50 oral morphine equivalents (OMEs), opioid-benzodiazepine overlap, and extended-release/long-acting opioid. We determined the proportion of opioid prescriptions, total OMEs, and high-risk prescriptions accounted for by "high-volume surgeons" (those in the ≥95th percentile for prescription counts). We used linear regression to identify characteristics associated with being a high-volume surgeon.

RESULTS

Among 15,493,018 opioid prescriptions included, 7,036,481 (45.4%) were high-risk. Among 114,610 surgeons, 5753 were in the 95th percentile or above for prescription count, with ≥520 prescriptions dispensed in 2019. High-volume surgeons accounted for 33.5% of opioid prescriptions, 52.8% of total OMEs, and 44.2% of high-risk prescriptions. Among high-volume surgeons, 73.9% were orthopedic surgeons and 60.6% practiced in the South. Older age, male sex, specialty, region, and lack of affiliation with academic institutions or health systems were correlated with high-risk prescribing.

CONCLUSIONS

The top 5% of surgeons account for 33.5% of opioid prescriptions and 45.4% of high-risk prescriptions. Quality improvement initiatives targeting these surgeons may have the greatest yield given their outsized role in high-risk prescribing.

Comparison of Opioids Prescribed by Advanced Practice Clinicians vs Surgeons After Surgical Procedures in the US

Importance

Advanced practice clinicians (APCs), defined as nurse practitioners and physician assistants, are increasingly being incorporated into surgical teams. Despite this inclusion, there are no recent national data on the role of these clinicians in surgical opioid prescribing or the dosing of such prescriptions.

Objective

To calculate the proportion of surgical opioid prescriptions written by APCs and to compare the total and daily dosages of these prescriptions with those written by surgeons.

Design, Setting, and Participants

This cross-sectional study used the Optum's De-Identified Clinformatics Data Mart, which contains deidentified claims from patients with private insurance and Medicare Advantage plans across the US. Adults and children who underwent 1 of 31 inpatient and outpatient surgical procedures from January 1, 2017, through November 30, 2019, were identified. The analysis was limited to procedures with 1 or more perioperative opioid prescriptions, defined as an opioid prescription dispensed within 3 days of the index date of surgery. Data were analyzed from April 1, 2021, to July 31, 2022.

Exposures

Prescriber specialty.

Main Outcomes and Measures

The outcome was the proportion of perioperative opioid prescriptions and refill prescriptions written by APCs. Linear regression was used to compare the total dosage of perioperative opioid prescriptions written by APCs vs surgeons measured in morphine milligram equivalents (MMEs). Models were adjusted for demographic characteristics, comorbidities, opioid-naive status, year of index date, hospitalization or observation status, surgical complications, and surgeon specialty. Analyses were conducted at the procedure level, and patients with multiple procedures were included.

Results

Analyses included 628 197 procedures for 581 387 patients (358 541 females [57.1%]; mean [SD] age, 56 [18] years). Overall, APCs wrote 119 266 (19.0%) of the 628 197 perioperative opioid prescriptions and 59 679 (25.1%) of the 237 740 refill prescriptions. Perioperative opioid prescriptions written by APCs had higher total dosages compared with those written by surgeons (adjusted difference, 40.0 MMEs; 95% CI, 31.3-48.7 MMEs). This difference persisted in a subgroup analysis limited to opioid-naïve patients (adjusted difference, 15.7 MMEs; 95% CI, 13.9-17.5 MMEs).

Conclusions and Relevance

In this cross-sectional analysis, one-fifth of perioperative opioid prescriptions and one-quarter of refill prescriptions were written by APCs. While surgeons wrote most perioperative opioid prescriptions that were intended for perioperative analgesia, higher total dosages from APCs suggest that opioid stewardship initiatives that support the role of APCs may be warranted.

Decreasing opioid prescribing at discharge while maintaining adequate pain management is sustainable

Background

In 2018, using a pragmatic multimodal approach, discharge opioid prescriptions were reduced without affecting pain control management. Herein, we assessed whether this approach was sustainable and whether discharge opioid prescriptions could be further reduced.

Methods

This is a single center prospective study of patients who underwent elective outpatient procedures provided by our institution's Acute Care Surgery Division surgeons. Adult patients who underwent elective surgeries performed by surgeons in the Division of Acute Care Surgery from November 2018 to June 2021 and agreed to participate were included. The opioid prescriptions pre-populated in the order set at discharge were reduced from 20 pills to 10 pills in May 2020. Demographics, opioid information, non-opioid adjuncts prescribed, reported use of opioids prescribed, and patients' satisfaction were collected. Opioids were converted to oral morphine equivalents (OME).

Results

A total of 178 patients were included. Elective surgeries performed mainly included inguinal hernia repair (38.8%), laparoscopic cholecystectomy (30.3%), cyst excision (13.5%), and umbilical hernia (8.4%). One hundred twenty-five and 53 patients underwent an elective operation with a surgeon in the Acute Care Surgery Division before and after the number of opioids pre-populated in the order set at discharge was reduced from 20 pills to 10 pills, respectively. Reducing the pre-populated discharge opioid prescriptions led to a significant decrease in OME prescribed (75 [75-76.5] vs. 80 [75-150], p < 0.001) without affecting patients' satisfaction with pain management (excellent/good: 87.8% vs. 84%; p = 0.305).

Conclusions

Our pragmatic multimodal approach is sustainable and allows for additional opioid prescription reduction without affecting patients' satisfaction with pain management.

Hippocampus-sensitive and striatum-sensitive learning one month after morphine or cocaine exposure in male rats

These experiments examined whether morphine and cocaine alter the balance between hippocampal and striatal memory systems measured long after drug exposure. Male rats received injections of morphine (5 mg/kg), cocaine (20 mg/kg), or saline for five consecutive days. One month later, rats were trained to find food on a hippocampus-sensitive place task or a striatum-sensitive response task. Relative to saline controls, morphine-treated rats exhibited impaired place learning but enhanced response learning; prior cocaine exposure did not significantly alter learning on either task. Another set of rats was trained on a dual-solution T-maze that can be solved with either place or response strategies. While a majority (67%) of control rats used place solutions, morphine treatment one month prior resulted in the exclusive use of response solutions (100%). Prior cocaine treatment did not significantly alter strategy selection. Molecular markers related to learning and drug abuse were measured in the hippocampus and striatum one month after drug exposure in behaviorally untested rats. Protein levels of glial-fibrillary acidic protein (GFAP), an intermediate filament specific to astrocytes, increased significantly in the hippocampus after morphine exposure, but not after cocaine exposure. Exposure to morphine or cocaine did not significantly change levels of brain-derived neurotrophic factor (BDNF) or a downstream target of BDNF signaling, glycogen synthase kinase 3β (GSK3β), in the hippocampus or striatum. Thus, exposure to morphine resulted in a long-lasting shift from hippocampal toward striatal dominance during learning, an effect that may be associated with lasting alterations in hippocampal astrocytes. Cocaine produced changes in the same direction, suggesting that use of a higher dose or longer duration of exposure might produce effects comparable to those seen with morphine.