Pharmacokinetics of opioids in liver disease

Managing your Palliative Patient

Palliative Care is the symptom management of any patient who has an irreversible, progressive, life-limiting condition and is not solely cancer patients. It aims to enhance quality of life, utilizing a holistic, multidisciplinary approach. Good symptom management of palliative patients is what every clinician should be able to deliver. This short article addresses the practical management of how to commence strong opioids, palliative surgical interventions, palliative emergencies and lastly, when do you stop treating a patient who is clinically deteriorating.

A Scoping Review and Consensus Recommendations for Emergency Medical Services Buprenorphine (EMS-Bupe) Programs

OBJECTIVES

Emergency Medical Services (EMS) agencies are beginning to provide low-barrier access to treatment for opioid use disorder (OUD) through the development of EMS buprenorphine (EMS-Bupe) programs. However, evidence-based practices for these programs are lacking. Our aim was to review the current literature on EMS and emergency department (ED) based buprenorphine treatment programs to provide consensus recommendations on the EMS-Bupe program development.

METHODS

We performed a scoping review of EMS-Bupe programs and ED medication for OUD (MOUD) programs. We searched Ovid MEDLINE(R), Embase.com, Cochrane Central Register of Controlled Trials and Web of Science (Science Citation Index) for English language articles and abstracts. Additional articles/abstracts as identified independently by coauthors were added. Recommendations were generated through consensus based on the findings of the scoping review and other relevant literature.

RESULTS

We identified a total of 9 EMS-Bupe articles/abstracts and 21 ED MOUD abstract, representing 5 EMS-Bupe programs in 4 states. There was significant variability between programs, from infrastructure, medication dosing, and retention rates. Results and recommendations were grouped into 8 categories: EMS program infrastructure, withdrawal classification thresholds, EMS protocol inclusion/exclusion criteria, buprenorphine dosing and adjunct medications, EMS disposition and scene times, EMS clinician training, referrals, and EMS data collection and quality management.

CONCLUSIONS

The EMS-Bupe program data are limited but show important variability. In general, we recommend that programs respond to community needs by establishing relationships with local resources. We also favor protocols that increase patient eligibility and treatment retention. Lastly, programs should consider low-barrier, patient-centered strategies aimed at preventing gaps in treatment.

Treatment of Pain in Cirrhosis: Advice to Caregivers of Those with Rock Livers

PURPOSE

When one considers the significant role of the liver in medication absorption and metabolism, clinicians must appreciate the important ramifications for medication dosing and monitoring in patients with cirrhosis. For many medications, dose adjustments may be necessary to minimize toxicities or avoid adverse effects from drug accumulation. Clinicians could be well served if they can understand in some detail how pharmacokinetic properties are altered in cirrhosis.

METHODS

A PubMed search of the English medical literature starting with 1980 using keywords cirrhosis, pain management, and analgesics was performed, and additional papers were found using references from the first round of papers.

FINDINGS

Patients with cirrhosis often have significant reductions in first-pass metabolism, altered volumes of distribution, and marked reductions in both renal and hepatic elimination of drugs. These factors may contribute to much higher levels of drug exposure compared to the general population. In terms of drug dosing, FDA labeling is often ambiguous and even incongruous with observed pharmacokinetic changes.

IMPLICATIONS

This article may provide guidance for clinicians to optimize pain management in people living with cirrhosis.

KEY MESSAGE

Current FDA labeling for dosing analgesic drugs in patients with cirrhosis is either vague or not consistent with findings from newer pharmacokinetic research. With this review, we hope to provide insight and guidance to clinicians on how to dose-adjust medications commonly utilized in pain management in these patients.

Simultaneously Predicting the Pharmacokinetics of CES1-Metabolized Drugs and Their Metabolites Using Physiologically Based Pharmacokinetic Model in Cirrhosis Subjects

Hepatic carboxylesterase 1 (CES1) metabolizes numerous prodrugs into active ingredients or direct-acting drugs into inactive metabolites. We aimed to develop a semi-physiologically based pharmacokinetic (semi-PBPK) model to simultaneously predict the pharmacokinetics of CES1 substrates and their active metabolites in liver cirrhosis (LC) patients. Six prodrugs (enalapril, benazepril, cilazapril, temocapril, perindopril and oseltamivir) and three direct-acting drugs (flumazenil, pethidine and remimazolam) were selected. Parameters such as organ blood flows, plasma-binding protein concentrations, functional liver volume, hepatic enzymatic activity, glomerular filtration rate (GFR) and gastrointestinal transit rate were integrated into the simulation. The pharmacokinetic profiles of these drugs and their active metabolites were simulated for 1000 virtual individuals. The developed semi-PBPK model, after validation in healthy individuals, was extrapolated to LC patients. Most of the observations fell within the 5th and 95th percentiles of simulations from 1000 virtual patients. The estimated AUC and Cmax were within 0.5-2-fold of the observed values. The sensitivity analysis showed that the decreased plasma exposure of active metabolites due to the decreased CES1 was partly attenuated by the decreased GFR. Conclusion: The developed PBPK model successfully predicted the pharmacokinetics of CES1 substrates and their metabolites in healthy individuals and LC patients, facilitating tailored dosing of CES1 substrates in LC patients.

Development of prescribing indicators related to opioid-related harm in patients with chronic pain in primary care-a modified e-Delphi study

BACKGROUND

Long-term opioid use is associated with dependency, addiction, and serious adverse events. Although a framework to reduce inappropriate opioid prescribing exists, there is no consensus on prescribing indicators for preventable opioid-related problems in patients with chronic pain in primary care in the UK. This study aimed to identify opioid prescription scenarios for developing indicators for prescribing opioids to patients with chronic pain in primary care.

METHODS

Scenarios of opioid prescribing indicators were identified from a literature review, guidelines, and government reports. Twenty-one indicators were identified and presented in various opioid scenarios concerning opioid-related harm and adverse effects, drug-drug interactions, and drug-disease interactions in certain disease conditions. After receiving ethics approval, two rounds of electronic Delphi panel technique surveys were conducted with 24 expert panellists from the UK (clinicians, pharmacists, and independent prescribers) from August 2020 to February 2021. Each indicator was rated on a 1-9 scale from inappropriate to appropriate. The score's median, 30th and 70th percentiles, and disagreement index were calculated.

RESULTS

The panel unanimously agreed that 15 out of the 21 opioid prescribing scenarios were inappropriate, primarily due to their potential for causing harm to patients. This consensus was reflected in the low appropriateness scores (median ranging from 1 to 3). There were no scenarios with a high consensus that prescribing was appropriate. The indicators were considered inappropriate due to drug-disease interactions (n = 8), drug-drug interactions (n = 2), adverse effects (n = 3), and prescribed dose and duration (n = 2). Examples included prescribing opioids during pregnancy, concurrently with benzodiazepines, long-term without a laxative prescription and prescribing > 120-mg morphine milligram equivalent per day or long-term duration over 3 months after surgery.

CONCLUSIONS

The high agreement on opioid prescribing indicators indicates that these potentially hazardous consequences are relevant and concerning to healthcare practitioners. Future research is needed to evaluate the feasibility and implementation of these indicators within primary care settings. This research will provide valuable insights and evidence to support opioid prescribing and deprescribing strategies. Moreover, the findings will be crucial in informing primary care practitioners and shaping quality outcome frameworks and other initiatives to enhance the safety and quality of care in primary care settings.

Factors Affecting and Promoting Health-related Quality of Life in Patients With Liver Cirrhosis: An Underestimated Domain in Patient Care

Cirrhosis patients have poor health-related quality of life (HRQoL). To enhance medical care and therapeutic approaches, it is crucial to identify factors that alter HRQoL in patients with cirrhosis. The present study aims to identify the potential factors affecting and promoting HRQoL in patients with liver cirrhosis. Four databases were extensively searched, including PubMed, Scopus, Embase, and Google Scholar. All original articles with liver cirrhosis and factor-altering HRQoL were included. The present study showed that elderly age, female gender, low family income, low body mass index (BMI), presence of anxiety and depression, presence of cirrhosis complications including ascites, hepatic encephalopathy (HE), and abnormal endoscopic findings, high disease severity score, presence of sarcopenia, disturbed sleep pattern, muscle cramps, poor sexual health, and increased levels of bilirubin, prothrombin time, and albumin-bilirubin ratio were the significant factors associated with lower HRQoL scores. Meanwhile, physical exercise, liver transplant, stem cell therapy, mindfulness, and the use of probiotics, rifaximin, and lactulose were associated with increased HRQoL scores. The present study recommends more prospective or randomized control trials with interventions including health education, yoga, psychotherapy, and other potential factors promoting HRQoL in patients with liver cirrhosis. The present study also emphasizes that the treating physician should consider taking HRQoL into account when prescribing medical therapy.

Changing Prevalence of Medication Use in People with Cirrhosis: A Retrospective Cohort Study Using Pharmaceutical Benefits Scheme Data

BACKGROUND

Safe and appropriate use of medicines is essential to improve health outcomes in cirrhosis. However, little is known about the number and type of medicines dispensed to people with cirrhosis in Australia, as this predominantly occurs in the community. We aimed to characterise the prescriptions dispensed to people with cirrhosis and explore changes in the use of medication groups over time.

METHODS

Pharmaceutical Benefits Scheme data between 1 January 2016 and 30 June 2020 was extracted for consenting CirCare participants (multi-site, prospective, observational study). Prescriptions dispensed from cirrhosis diagnosis until liver transplant or death were included. Safety classifications for dispensed medicines were defined using published evidence-based recommendations. The pattern of medication use was analysed in 6-monthly time intervals. Generalised estimating equations models were used to estimate the change in consumption of medicines over time.

RESULTS

Five hundred twenty-two patients (mean age 60 years, 70% male, 34% decompensated at recruitment) were dispensed 89,615 prescriptions during the follow-up period, representing a median of 136 [interquartile range (IQR) 62-237] prescriptions and a median of 16 (IQR 11-23) unique medicines per patient (total n = 9306 medicines). The most commonly used medicines were proton pump inhibitors (PPIs) (dispensed at least once to 73% of patients), opioids (68%) and antibiotics (89%). Polypharmacy was prevalent, with 59-69% of observed participants in each time period dispensed five or more unique medicines. Prescription medication use increased over time (p < 0.001) independently of age, comorbidity burden and liver disease aetiology. The likelihood of taking PPIs, opioids, antidepressants and inhaled medicines also increased with each successive time period. Use of angiotensin therapies, metformin and statins differed over time between patients with compensated versus decompensated cirrhosis. General practitioners prescribed 69% of dispensed medicines, including a higher proportion of 'unsafe' and 'safety unknown' medicines compared with consultants/specialists (p < 0.001).

CONCLUSIONS

Polypharmacy is common in people with cirrhosis and some medication groups may be overused. Pharmacovigilance is required and future medication safety efforts should target high-risk prescribing practices and promote medication rationalisation in the community.

Acetaminophen: A Liver Killer or Thriller

Acetaminophen, or paracetamol, ranks among the most extensively utilized analgesic and antipyretic medications globally. The administration of acetaminophen to individuals with underlying liver disease has long sparked concerns regarding the potential risk of hepatotoxicity. However, the available literature and recommendations consider it a safe option in all forms of liver diseases and is deemed safe when used at recommended doses. This article aims to offer a concise review of the pharmacokinetics, toxicity profile, and the intricate considerations surrounding the safety of acetaminophen in patients with liver disease. By delving into the liver-acetaminophen interactions, we seek to provide a nuanced perspective on the use of acetaminophen in this critical patient population.

Impact of renal and hepatic function on first opioid prescriptions in cancer patients: an acute care hospital database study linked to medical claims data and laboratory data

BACKGROUND

Cancer patients often have impaired renal and hepatic function. Opioids are essential to relieve painful symptoms in cancer patients. However, it is unknown which opioids are first prescribed for cancer patients with renal and hepatic impairment. The objective is to investigate the association between the type of first prescribed opioids and the renal/hepatic function of cancer patients.

METHODS

We used a multicenter database from 2010 to 2019. The number of days from the first opioid prescription to the death was defined as the prognostic period. This period was divided into six categories. The prevalence of opioid prescriptions was calculated for each assessment of renal and hepatic function, divided into prognostic periods. Multinomial logistic regression analysis was used to explore the influence of renal and hepatic function on the first opioid choice.

RESULTS

The study included 11 945 patients who died of cancer. In all prognostic period categories, the patients with worse renal function received fewer morphine prescriptions. No trend was observed in hepatic function. The odds ratio of oxycodone to morphine with reference to estimated glomerular filtration rate (eGFR) ≥90 was 1.707 (95% confidence interval: 1.433-2.034) for estimated glomerular filtration rate <30. The odds ratio of fentanyl to morphine with reference to estimated glomerular filtration rate ≥90 was 1.785 (95% confidence interval: 1.492-2.134) for estimated glomerular filtration rate <30. No association was identified between hepatic function and the choice of prescribed opioids.

CONCLUSION

Cancer patients with renal impairment tended to avoid morphine prescriptions, and no specific trend was observed in cancer patients with hepatic impairment.

Predictors of Multiwave Opioid Use Among Older American Adults

Background and Objectives

Despite limited analgesic benefits, long-term opioid therapy (L-TOT) is common among older adults with chronic pain. Extended opioid use poses a threat to older adults as aging metabolisms retain opioids for longer, increasing the risk of injury, overdose, and other negative health outcomes. In contrast to predictors of general opioid use, predictors of L-TOT in older adults are not well documented. We aimed to identify such predictors using all available data on self-reported opioid use in the Health and Retirement Study.

Research Design and Methods

Using 5 waves of data, respondents (N = 10,713) aged 51 and older were identified as reporting no opioid use (n = 8,621), a single wave of use (n = 1,410), or multiple waves of use (n = 682). We conducted a multinomial logistic regression to predict both single- and multiwave opioid use relative to no use. Demographic, socioeconomic, geographic, health, and health care-related factors were included in our model.

Results

Multivariable findings show that, relative to nonusers, both single- and multiwave users were significantly more likely to be younger (relative risk ratio [RRR] = 1.33; RRR = 2.88); report lower household wealth (RRR = 1.47; RRR = 2.88); live in the U.S. Midwest (RRR = 1.29; RRR = 1.56), South (RRR = 1.34; RRR = 1.58), or West (RRR = 1.46; RRR = 2.34); experience interfering pain (RRR = 1.59; RRR = 3.39), back pain (RRR = 1.35; RRR = 1.53), or arthritic pain (RRR = 1.46; RRR = 2.32); and see the doctor frequently (RRR = 1.50; RRR = 2.02). Multiwave users were less likely to be Black (RRR = 0.69) or Hispanic (RRR = 0.45), and less likely to be never married (RRR = 0.52).

Discussion and Implications

We identified demographic, socioeconomic, geographic, and health care-related predictors of chronic multiyear opioid use. Our focus on individuals taking opioids for this extended duration is novel. Differences in opioid use by geographic region and frequency of doctor visits particularly warrant attention from policy-makers and researchers. We make additional recommendations based on a sensitivity analysis limited to 2016-2020 data.

2022 KLCA-NCC Korea practice guidelines for the management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the fourth most common cancer among men in South Korea, where the prevalence of chronic hepatitis B infection is high in middle and old age. The current practice guidelines will provide useful and sensible advice for the clinical management of patients with HCC. A total of 49 experts in the fields of hepatology, oncology, surgery, radiology, and radiation oncology from the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2018 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions. These guidelines provide useful information and direction for all clinicians, trainees, and researchers in the diagnosis and treatment of HCC.

Clinical Guideline on Perioperative Management of Patients with Advanced Chronic Liver Disease

(1) Background: Patients with advanced chronic liver disease (ACLD) are living longer with more comorbidities because of improved medical and surgical management. However, patients with ACLD are at increased risk of perioperative morbidity and mortality; (2) Methods: We conducted a comprehensive review of the literature to support a narrative clinical guideline about the assessment of mortality risk and management of perioperative morbidity in patients with ACLD undergoing surgical procedures; (3) Results: Slight data exist to guide the perioperative management of patients with ACLD, and most recommendations are based on case series and expert opinion. The severity of liver dysfunction, portal hypertension, cardiopulmonary and renal comorbidities, and complexity of surgery and type (elective versus emergent) are predictors of perioperative morbidity and mortality. Expert multidisciplinary teams are necessary to evaluate and manage ACLD before, during, and after surgical procedures; (4) Conclusions: This clinical practice document updates the available data and recommendations to optimize the management of patients with advanced chronic liver disease who undergo surgical procedures.

Pharmacological data science perspective on fatal incidents of morphine treatment

Morphine prescribed for analgesia has caused drug-related deaths at an estimated incidence of 0.3% to 4%. Morphine has pharmacological properties that make it particularly difficult to assess the causality of morphine administration with a patient's death, such as its slow transfer between plasma and central nervous sites of action and the existence of the active metabolite morphine-6-glucuronide with opioid agonistic effects, Furthermore, there is no well-defined toxic dose or plasma/blood concentration for morphine. Dosing is often adjusted for adequate pain relief. Here, we summarize reported deaths associated with morphine therapy, including associated morphine exposure and modulating patient factors such as pharmacogenetics, concomitant medications, or comorbidities. In addition, we systematically analyzed published numerical information on the stability of concentrations of morphine and its relevant metabolites in biological samples collected postmortem. A medicolegal case is presented in which the causality of morphine administration with death was in dispute and pharmacokinetic modeling was applied to infer the administered dose. The results of this analytical review suggest that (i) inference from postmortem blood concentrations to the morphine dose administered has low validity and (ii) causality between a patient's death and the morphine dose administered remains a highly context-dependent and collaborative assessment among experts from different medical specialties.

A review of the safety of buprenorphine in special populations

Rates of opioid misuse and opioid use disorder have been increasing in recent years. Buprenorphine has emerged as an appealing medication for its use not only as treatment for opioid use disorder, but also as an opioid for chronic pain that has a ceiling effect on risks associated with opioid therapy. As other opioid prescribing decreases, buprenorphine prescribing continues to increase. As a result, it is imperative to understand the safety and efficacy of its use in special populations. This review article will explore the safety and efficacy of buprenorphine when used in subjects with hepatic and renal impairment, the elderly, and pregnant women. While manufacturer labeling for buprenorphine products may caution against their use in these populations, further examination of available data indicates that buprenorphine can be used safely and effectively for both chronic pain and/or opioid use disorder in all four of these populations.

2022 KLCA-NCC Korea Practice Guidelines for the Management of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the fourth most common cancer among men in South Korea, where the prevalence of chronic hepatitis B infection is high in middle and old age. The current practice guidelines will provide useful and sensible advice for the clinical management of patients with HCC. A total of 49 experts in the fields of hepatology, oncology, surgery, radiology, and radiation oncology from the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2018 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions. These guidelines provide useful information and direction for all clinicians, trainees, and researchers in the diagnosis and treatment of HCC.

2022 KLCA-NCC Korea practice guidelines for the management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide and the fourth most common cancer among men in South Korea, where the prevalence of chronic hepatitis B infection is high in middle and old age. The current practice guidelines will provide useful and sensible advice for the clinical management of patients with HCC. A total of 49 experts in the fields of hepatology, oncology, surgery, radiology, and radiation oncology from the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2018 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions. These guidelines provide useful information and direction for all clinicians, trainees, and researchers in the diagnosis and treatment of HCC.

Substances use disorders and liver injury: a concise review

Substance use disorders (SUDs) are often associated with alcohol use disorders (AUDs) and psychiatric comorbidities. In addition, they are often subjected to polytherapy. For these reasons SUDs patients are at greater risk of developing liver disease. In this concise review, liver damage from amphetamines, cannabinoids, cocaine and opioids is analyzed and the need to identify a possible associated alcohol use disorder is also suggested. Early identification of liver fibrosis is required in SUDs patients. Fibrosis is the most significant predictor of both prognosis and long-term survival. Its identification helps to promote the abstention from substances and alcohol. Active use of heroin, cocaine and synthetic substances is an absolute contraindication for liver transplantation. In cases of remission and adherence to a significant care path, the patient is re-evaluated. An addiction specialist should be present within the transplant team. If this is not present, a close collaboration with an addiction unit is mandatory.

Pre-procedural Preparation and Sedation for Gastrointestinal Endoscopy in Patients with Advanced Liver Disease

Gastrointestinal endoscopy in patients with advanced liver disease poses various challenges, a major one being procedural sedation and its associated considerations. While sedation during endoscopy can improve patient comfort, decrease anxiety, and facilitate procedural completion, in patients with advanced liver disease, it is also associated with substantial and unique risks due to alterations in drug metabolism and other factors. As such, the choice of sedative agent(s) and related logistics may require careful inter-disciplinary planning and individualized considerations. Furthermore, a large proportion of agents require dose reductions and particular monitoring of the vital signs, level of consciousness, and other indices. In the present review, we provide a contemporary overview of procedural sedation considerations, commonly used intravenous sedatives, and second-line as well as novel sedatives for gastrointestinal endoscopy in patients with advanced liver disease.

Hepatic impairment as a risk factor of adverse drug reactions

There are a lot of clinical variants of hepatic impairment ranging from asymptomatic increase in transaminases to acute liver failure and fulminant hepatitis. Hepatic impairment is a polietiologic syndrome. According to the epidemiological study conducted in the United States (19982008), the main causes of hepatic impairment were paracetamol overdose (46%), idiopathic liver dysfunction (14%), other drugs (excluding paracetamol, 11%), viral hepatitis B (7%), other infectious and non-infectious diseases with liver damage (except for viral hepatitis) 7%, autoimmune hepatitis (5%), ischemic hepatitis (syn. hypoxic hepatitis, liver infarction) 4%, viral hepatitis A (3%) and Wilson's disease (2%). Hepatic impairment have a direct impact on the pharmacokinetics and pharmacodynamics of drugs decreasing clearance, elimination and excretion of drugs. Also Transjugular intrahepatic porto-systemic shunts, which are often used to treat portal hypertension in patients with liver cirrhosis, can significantly reduce the presystemic elimination of drugs, thereby increasing their absorption. Moreover, in patients with liver cirrhosis, concomitant renal dysfunction also requires an adjustment of the dose of drugs. Correction of pharmacotherapy in accordance to pharmacokinetic and pharmacodynamic changes of drugs ingested by patients with impaired liver function will improve the quality of medical care and reduce the risks of adverse drug reactions.

Liver and Biliary Disease of Pregnancy and Anesthetic Implications: A Review

Liver and biliary disease complicates pregnancy in varying degrees of severity to the mother and fetus, and anesthesiologists may be asked to assist in caring for these patients before, during, and after birth of the fetus. Therefore, it is important to be familiar with how different liver diseases impact the pregnancy state. In addition, knowing symptoms, signs, and laboratory markers in the context of a pregnant patient will lead to faster diagnosis and treatment of such patients. This review article discusses changes in physiology of parturients, patients with liver disease, and parturients with liver disease. Next, general treatment of parturients with acute and chronic liver dysfunction is presented. The article progresses to specific liver diseases with treatments as they relate to pregnancy. And finally, important aspects to consider when anesthetizing parturients with liver disease are discussed.

Buprenorphine: Far Beyond the "Ceiling"

Chronic pain, including neuropathic pain, represents an untreated disease with important repercussions on the quality of life and huge costs on the national health system. It is well known that opioids are the most powerful analgesic drugs, but they represent the second or third line in neuropathic pain, that remain difficult to manage. Moreover, these drugs show several side effects that limit their use. In addition, opioids possess addictive properties that are associated with misuse and drug abuse. Among available opioids compounds, buprenorphine has been suggested advantageous for a series of clinical reasons, including the effectiveness in neuropathic pain. Some properties are partly explained by its unique pharmacological characteristics. However, questions on the dynamic profile remain to be answered. Pharmacokinetics optimization strategies, and additional potentialities, are still to be explored. In this paper, we attempt to conceptualize the potential undiscovered dynamic profile of buprenorphine.

Top Ten Tips Palliative Care Clinicians Should Know About End-Stage Liver Disease

End-stage liver disease (ESLD) is an increasingly prevalent condition with high morbidity and mortality, especially for those ineligible for liver transplantation. Patients with ESLD, along with their family caregivers, have significant needs related to their quality of life, and there is increasing attention being paid to integration of palliative care (PC) principles into routine care throughout the disease spectrum. To provide upstream care for these patients and their family caregivers, it is essential for PC providers to understand their complex psychosocial and physical needs and to be aware of the unique challenges around medical decision making and end-of-life care for this patient population. This article, written by a team of liver and PC experts, shares 10 high-yield tips to help PC clinicians provide better care for patients with advanced liver disease.

Management of Chronic Pain in Nursing Homes: Navigating Challenges to Improve Person-Centered Care

Despite the dynamic demands in the nursing home (NH), a definitive approach to managing chronic pain in older adults has yet to be established. Due to concerns for potential adverse pharmacologic effects, balancing appropriate pain management is a challenge among NH residents. The challenges encompass but are not limited to medical complexities, functional disabilities, and physical frailty. Barriers to the successful implementation of a comprehensive chronic pain management at the NH may include ambiguous directions on specific therapeutic interventions, insufficient guidance on treatment duration, and limited available treatment options. The Centers for Medicare and Medicaid Services' reporting requirement of adequate pain control among NH residents coupled with widely variable clinician-prescribing habits highlights the difficulties in overcoming the preceding challenges and barriers. The Coronavirus Disease 2019 (COVID-19) pandemic has further complicated pain management due to its negative consequences on well-being of residents of NHs. Associated symptoms of psychosocial stress, anxiety and depression, and chronic pain symptoms can exacerbate during the COVID-19 pandemic, leading to increased requirement for pain medications including but not limited to opioids. Pain is a multidimensional symptom and requires a strategic multimodal approach for its management. Nonpharmacologic modalities are underutilized in the NH setting and are the preferred first steps for mild pain, and nonopioid pharmacological agents can be added as a second step for a synergistic effect for moderate to severe pain. Opioids should be used as a last resort. Short-acting opioids are preferred over extended-release/long-acting opioids for chronic pain. Clinicians are encouraged to engage residents in proactive strategies in managing their pain, and to set realistic expectations toward improving their quality of life, as complete elimination of pain is not feasible in most cases. This review article provides the interdisciplinary team with a contemporary perspective of the multitude of changes and challenges influencing the prescribing as well as deprescribing of various pain medications.

Risk of ambulatory colonoscopy in patients with cirrhosis: a propensity-score matched cohort study

Background and study aims  Patients with cirrhosis demonstrate alterations in physiology, hemodynamics, and immunity which may increase procedural risk. There exist sparse data regarding the safety of performing ambulatory colonoscopy in patients with cirrhosis. Patients and methods  From a population-based sample of three North American states (California, Florida, and New York), we collected data on 3,590 patients with cirrhosis who underwent ambulatory colonoscopy from 2009 to 2014. We created a control cohort propensity score-matched for cirrhotic severity who did not undergo colonoscopy (N = 3,590) in order to calculate the attributable risk for adverse events. The primary endpoint was the rate of unplanned hospital encounters (UHEs) within 14 days of colonoscopy (or from a synthetic index date for the control cohort). Predictors for UHE were assessed in multivariable regression. Results  The attributable risk for any UHE following colonoscopy was 3.1 % (confidence interval [CI] 2.1-4.1 %, P  < 0.001). There was increased risk for infection (0.9 %, CI 0.7-1.1 %), spontaneous bacterial peritonitis (0.1 %, CI 0.0-0.3 %), decompensation of ascites (0.3 %, CI 0.2-0.4 %), and cardiovascular event (0.4 %, CI 0.3-0.5 %). There was no increased attributable risk for gastrointestinal bleeding, perforation, or development of the hepatorenal syndrome. The presence of ascites at time of procedure was the only predictor for UHE in the fully-adjusted model (OR 2.6, CI 1.9-3.5, P  < 0.001). Conclusions  There is a moderate though detectable increase in risk for adverse event following ambulatory colonoscopy in patients with cirrhosis. The presence of ascites in particular portends higher risk. These data may guide clinicians when counseling patients with cirrhosis on the choice of colorectal cancer screening modality.

Comparison of Fentanyl versus Meperidine in Combination with Midazolam for Sedative Colonoscopy in Korea

Background/Aims

Combination of midazolam and opioids is used widely for endoscopic sedation. Compared with meperidine, fentanyl is reportedly associated with rapid recovery, turnover rate of endoscopy room, and quality of endoscopy. We compared fentanyl with meperidine when combined with midazolam for sedative colonoscopy.

Methods

A retrospective, cross-sectional, 1:2 matching study was conducted. Induction and recovery time were compared as the primary outcomes. Moreover, cecal intubation time, withdrawal time, total procedure time of colonoscopy, paradoxical reaction, adenoma detection rate, and adverse effect of midazolam or opioids were assessed as the secondary outcomes.

Results

A total of 129 subjects (43 fentanyl vs. 86 meperidine) were included in the analysis. The fentanyl group showed significantly more rapid induction time (4.5±2.7 min vs. 7.5±4.7 min, p<0.001), but longer recovery time (59.5±25.6 min vs. 50.3±10.9 min, p=0.030) than the meperidine group. In multivariate analysis, the induction time of the fentanyl group was 3.40 min faster (p<0.001), but the recovery time was 6.38 min longer (p=0.046) than that of the meperidine group. There was no difference in withdrawal time and adenoma detection rate between the two groups.

Conclusions

The fentanyl group had more rapid sedation induction time but longer recovery time than the meperidine group.

Risk factors for severe opioid-induced respiratory depression in hospitalized adults: A case-control study

Background: Opioids are commonly prescribed to hospitalized adults to promote adequate pain relief, yet they can cause potentially fatal respiratory depression.

Aim: The aim of this study was to examine the risk factors for the development of severe opioid-induced respiratory depression (OIRD) in hospitalized adults to ensure adequate monitoring of high-risk patients.

Methods: A retrospective case–control study was conducted using data from the medical records of a university-affiliated hospital in Canada. Cases were eligible if they were adults (≥18 years old) and received opioid analgesia within 24 h of naloxone administration for respiratory depression. Controls had the same eligibility criteria, except for respiratory depression and naloxone administration. The case–control ratio was 1:1, and they were matched based on sex, type of unit, opioid molecule and the presence/absence of medication errors.

Results: A total of 133 cases and 133 controls were included. Following cumulative risk factor analysis, renal failure (odds ratio [OR] = 2.176, 95% confidence interval [CI], 1.021–4.640, P = 0.044), the first 24 h of opioid administration (OR = 1.899, 95% CI, 1.090–3.309, P = 0.024), concomitant central nervous system (CNS) depressants (OR = 1.785, 95% CI, 1.023–3.113, P = 0.041), and increasing age (OR = 1.019, 95% CI, 1.002–1.035, P = 0.028) were positively associated with severe OIRD.

Conclusions: Some adult hospitalized patients were at higher risk of experiencing severe OIRD, such as those with renal failure, those in their first 24 h of opioid administration, those receiving CNS depressants in addition to opioids, and those with an advanced age. These results will assist with the screening of patients at higher risk for severe OIRD, which is key to implementing appropriate monitoring and enhancing the safety of opioid use in hospital settings.

Drug-Induced Liver Injury in the Setting of Analgesic Use

No professional society has created guidelines to aid clinicians in the management of analgesics in the setting of hepatic injury. Acetaminophen overdose is the most common cause of acute liver failure in the United States. In the setting of acetaminophen toxicity, N-acetylcysteine remains the standard of care. Other analgesics including nonsteroidal antiinflammatory drugs, opiates, tricyclic antidepressants, and anticonvulsants rarely cause liver injury.

Prescribing in Chronic Severe Hepatic Impairment

Therapeutic Reviews aim to provide essential independent information for health professionals about drugs used in palliative and hospice care. Additional content is available via www.palliativedrugs.com. The series editors welcome feedback on the articles.

2018 Korean Liver Cancer Association-National Cancer Center Korea Practice Guidelines for the Management of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer globally and the fourth most common cancer in men in Korea, where the prevalence of chronic hepatitis B infection is high in middle-aged and elderly patients. These practice guidelines will provide useful and constructive advice for the clinical management of patients with HCC. A total of 44 experts in hepatology, oncology, surgery, radiology, and radiation oncology in the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2014 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions.

Pharmacokinetics of Fentanyl and Its Derivatives in Children: A Comprehensive Review

Fentanyl and its derivatives sufentanil, alfentanil, and remifentanil are potent opioids. A comprehensive review of the use of fentanyl and its derivatives in the pediatric population was performed using the National Library of Medicine PubMed. Studies were included if they contained original pharmacokinetic parameters or models using established routes of administration in patients younger than 18 years of age. Of 372 retrieved articles, 44 eligible pharmacokinetic studies contained data of 821 patients younger than 18 years of age, including more than 46 preterm infants, 64 full-term neonates, 115 infants/toddlers, 188 children, and 28 adolescents. Underlying diagnoses included congenital heart and pulmonary disease and abdominal disorders. Routes of drug administration were intravenous, epidural, oral-transmucosal, intranasal, and transdermal. Despite extensive use in daily clinical practice, few studies have been performed. Preterm and term infants have lower clearance and protein binding. Pharmacokinetics was not altered by chronic renal or hepatic disease. Analyses of the pooled individual patients' data revealed that clearance maturation relating to body weight could be best described by the Hill function for sufentanil (R ² = 0.71, B _max 876 mL/min, K ₅₀ 16.3 kg) and alfentanil (R ² = 0.70, B _{max (fixed)} 420 mL/min, K ₅₀ 28 kg). The allometric exponent for estimation of clearance of sufentanil was 0.99 and 0.75 for alfentanil clearance. Maturation of remifentanil clearance was described by linear regression to bodyweight (R ² = 0.69). The allometric exponent for estimation of remifentanil clearance was 0.76. For fentanyl, linear regression showed only a weak correlation between clearance and bodyweight in preterm and term neonates (R ² = 0.22) owing to a lack of data in older age groups. A large heterogeneity regarding study design, clinical setting, drug administration, laboratory assays, and pharmacokinetic estimation was observed between studies introducing bias into the analyses performed in this review. A limitation of this review is that pharmacokinetic data, based on different modes of administration, dosing schemes, and parameter estimation methods, were combined.

2018 Korean Liver Cancer Association-National Cancer Center Korea Practice Guidelines for the Management of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer globally and the fourth most common cancer in men in Korea, where the prevalence of chronic hepatitis B infection is high in middle-aged and elderly patients. These practice guidelines will provide useful and constructive advice for the clinical management of patients with HCC. A total of 44 experts in hepatology, oncology, surgery, radiology and radiation oncology in the Korean Liver Cancer Association-National Cancer Center Korea Practice Guideline Revision Committee revised the 2014 Korean guidelines and developed new recommendations that integrate the most up-to-date research findings and expert opinions.

Characteristics of Opioid Prescriptions to Veterans With Cirrhosis

BACKGROUND & AIMS

Despite increased risks for adverse effects in patients with cirrhosis, little is known about opioid prescriptions for this population. We aimed to assess time trends in opioid prescribing and factors associated with receiving opioids among patients with cirrhosis.

METHODS

Among Veterans with cirrhosis, identified using national Veterans Health Administration data (2005-2014), we assessed characteristics of patients and their prescriptions for opioids. We calculated the annual proportion of patients receiving any opioid prescription. Among opioid recipients, we assessed prescriptions that were long-term (>90 days' supply), for high doses (>100 MME/day), or involved combinations of opioids and acetaminophen or benzodiazepine. We evaluated patient characteristics independently associated with long-term and any opioid prescriptions using mixed-effects regression models.

RESULTS

Among 127,239 Veterans with cirrhosis, 97,974 (77.0%) received a prescription for an opioid. Annual opioid prescriptions increased from 36% in 2005 to 47% in 2014 (P < .01). Among recipients of opioids, the proportions of those receiving long-term prescriptions increased from 47% in 2005 to 54% in 2014 (P < .01), and19%-21% received prescriptions for high-dose opioids. Prescriptions for combinations of opioids and acetaminophen decreased from 68% in 2005 to 50% in 2014 (P < .01) and for combinations of opioids and benzodiazepines decreased from 24% to 19% over this time (P < .01). Greater probability of long-term opioid prescriptions was independently associated with younger age, female sex, white race, hepatitis C, prior hepatic decompensation, hepatocellular carcinoma, mental health disorders, nicotine use disorders, medical comorbidities, surgery, and pain-related conditions.

CONCLUSION

Among Veterans with cirrhosis, 36%-47% were prescribed opioids in each year. Mental health disorders and hepatic decompensation were independently associated with long-term opioid prescriptions.

Opioid and benzodiazepine prescription among patients with cirrhosis compared to other forms of chronic disease

Objective

Data on patterns and correlates of opioid and benzodiazepines prescriptions among patients with chronic conditions are limited. Given a diminished capacity for hepatic clearance, patients with cirrhosis represent a high risk group for use. The aim of this study was to characterise the patterns and correlates of prescription opioid, benzodiazepine and dual drug prescriptions among individuals with common chronic diseases.

Design

Analysis of Truven Marketscan database to evaluate individuals with drug coverage with cirrhosis (n=169,181), chronic hepatitis C without cirrhosis (n=210 191), congestive heart failure (n=766 840) or chronic obstructive pulmonary disease (n=1 438 798). Pharmacy files were examined for outpatient prescriptions.

Results

Patients with cirrhosis had a significantly higher prevalence of opioid prescriptions (37.1 per 100 person-years vs 24.3–26.0, p≤0.001) and benzodiazepine prescriptions (21.3 per 100 person-years vs 12.1–12.9, p<0.001). High dose opioid prescription (>90 daily oral morphine equivalents) (29.1% vs 14.4%, p<0.001) and dual opioid and benzodiazepine prescription (17.5% vs 9.6%–10.5 %, p<0.001) were also significantly more prevalent in cirrhosis. High dose opioid prescription was greater in men, individuals ages 40–59, in the Western USA, and among those with a mental health or substance abuse condition. Dual opioid and benzodiazepine prescription were highest among those with alcoholic cirrhosis and middle aged-adults.

Conclusion

Persons with cirrhosis have significantly higher rates of prescription opioid and benzodiazepine prescription compared to others with chronic diseases despite their high risk for adverse drug reactions. Demographics and mental health or substance abuse history can help identify high risk groups to target interventions.

Safety and effectiveness of midazolam for cirrhotic patients undergoing endoscopic variceal ligation

BACKGROUND/AIMS

Endoscopic variceal ligation (EVL) is an established treatment for esophageal variceal bleeding. Midazolam (MDZ) is most commonly used for sedation during endoscopic procedures. However, adverse events (AEs) may occur more frequently in patients with cirrhosis due to altered MDZ metabolism.

MATERIALS AND METHODS

We retrospectively reviewed the records of 325 patients with cirrhosis who received EVL.

RESULTS

No significant differences were found in treatment outcome and procedure time among 151 patients in the MDZ group and 169 patients in the non-MDZ group. Desaturation (23.2% vs. 7.7%, p<0.01), bradycardia (22.5% vs. 17.2%, p=0.03), and hepatic encephalopathy (HE) (6.6% vs. 0.6%, p<0.01) were more common in the MDZ group than in the non-MDZ group. Logistic regression analyses revealed that an Eastern Cooperative Oncology Group (ECOG) score of ≥2 (p<0.01) and the use of MDZ (p<0.01) were associated with the development of overall AEs. An ECOG score of ≥2 (p=0.01), high serum creatinine level (p=0.02), and the use of MDZ (p<0.01) were significant risk factors for HE.

CONCLUSION

Extreme caution should be taken when sedating patients with cirrhosis receiving EVL due to the AEs associated with the use of MDZ.

Approach to buprenorphine use for opioid withdrawal treatment in the emergency setting

INTRODUCTION

Opioid use disorder (OUD) is increasing in prevalence throughout the world, with approximately three million individuals in the United States affected. Buprenorphine is a medication designed, researched, and effectively used to assist in OUD recovery.

OBJECTIVE

This narrative review discusses an approach to initiating buprenorphine in the emergency department (ED) for opioid-abuse recovery.

DISCUSSION

Buprenorphine is a partial mu-opioid receptor agonist with high affinity and low intrinsic activity. Buprenorphine's long half-life, high potency, and 'ceiling effect' for both euphoric sensation and adverse effects make it an optimal treatment alternative for patients presenting to the ED with opioid withdrawal. While most commonly provided as a sublingual film or tablet, buprenorphine can also be delivered via transbuccal, transdermal, subdermal (implant), subcutaneous, and parenteral routes. Prior to ED administration, caution is recommended to avoid precipitation of buprenorphine-induced opioid withdrawal. Following the evaluation of common opioid withdrawal symptoms, a step-by-step approach to buprenorphine can by utilized to reach a sustained withdrawal relief. A multimodal medication-assisted treatment (MAT) plan involving pharmacologic treatment, as well as counseling and behavioral therapy, is essential to maintaining opioid remission. Patients may be safely discharged with safe-use counseling, close outpatient follow-up, and return precautions for continued management of their OUD. Establishing a buprenorphine program in the ED involves a multifactorial approach to establish a pro-buprenorphine culture.

CONCLUSIONS

Buprenorphine is an evidence-based, safe, effective treatment option for OUD in an ED-setting. Though successfully utilized by many ED-based treatment programs, the stigma of 'replacing one opioid with another' remains a barrier. Evidence-based discussions on the safety and benefits of buprenorphine are essential to promoting a culture of acceptance and optimizing ED OUD treatment.

Treating Chronic Pain: An Overview of Clinical Studies Centered on the Buprenorphine Option

The buprenorphine receptor binding profile is unique in that it binds to all three major opioid receptors (mu, kappa, delta), and also binds to the orphan-like receptor, the receptor for orphanin FQ/nociceptin, with lower affinity. Within the mu receptor group, buprenorphine analgesia in rodents is dependent on the recently discovered arylepoxamide receptor target in brain, which involves a truncated 6-transmembrane mu receptor gene protein, distinguishing itself from morphine and most other mu opioids. Although originally designed as an analgesic, buprenorphine has mainly been used for opioid maintenance therapy and only now is increasingly recognized as an effective analgesic with an improved therapeutic index relative to certain potent opioids. Albeit a second-, third-, or fourth-line analgesic, buprenorphine is a reasonable choice in certain clinical situations. Transdermal patches and buccal film formulations are now commercially available as analgesics. This review discusses buprenorphine pharmacodynamics and pharmacokinetics, use in certain populations, and provides a synopsis of systematic reviews and randomized analgesic trials. We briefly discuss postoperative management in patients receiving buprenorphine maintenance therapy, opioid equivalence to buprenorphine, rotations to buprenorphine from other opioids, and clinical relevance of buprenorphine-related QTc interval changes.

Liver Disease and Fibrosis Assessment in Substance Use-Related Disorders

Substance users have the highest prevalence of hepatitis C virus (HCV) infection but have rarely been treated, largely because of their mistrust of the health care system, misconceptions about the consequences of the infection, and concerns regarding interferon-related side effects. With the development of highly efficacious, interferon-free therapeutic regimens without significant side effects, the concept of colocating HCV and substance use treatment would appear to be highly feasible. This process has been further facilitated by widespread clinical adaptation of noninvasive assays for fibrosis assessment, which could be performed routinely in substance use treatment facilities. The most commonly used noninvasive fibrosis assessment methods are serum marker indexes and transient elastography, both of which are very accurate in detecting cirrhosis or the absence of fibrosis, but much less successful in identifying intermediate fibrosis stages. The effect of drugs of abuse on the liver is not completely understood or sufficiently studied. There are no indications that heroin and cocaine affect fibrosis progression, but some recreational drugs (eg, alcohol and cannabis) can induce hepatic injury. In addition, knowledge gaps exist on the effect of impaired liver function on metabolism or transport of agents used to treat substance disorders as well as their interactions with HCV antivirals.

A rapid solution-based method for determining the affinity of heroin hapten-induced antibodies to heroin, its metabolites, and other opioids

We describe for the first time a method that utilizes microscale thermophoresis (MST) technology to determine polyclonal antibody affinities to small molecules. Using a novel type of heterologous MST, we have accurately measured a solution-based binding affinity of serum antibodies to heroin which was previously impossible with other currently available methods. Moreover, this mismatch approach (i.e., using a cross-reactive hapten tracer) has never been reported in the literature. When compared with equilibrium dialysis combined with ultra-performance liquid chromatography/tandem mass spectrometry (ED-UPLC/MS/MS), this novel MST method yields similar binding affinity values for polyclonal antibodies to the major heroin metabolites 6-AM and morphine. Additionally, we herein report the method of synthesis of this novel cross-reactive hapten, MorHap-acetamide—a useful analog for the study of heroin hapten–antibody interactions. Using heterologous MST, we were able to determine the affinities, down to nanomolar accuracies, of polyclonal antibodies to various abused opioids. While optimizing this method, we further discovered that heroin is protected from serum esterase degradation by the presence of these antibodies in a concentration-dependent manner. Lastly, using affinity data for a number of structurally different opioids, we were able to dissect the moieties that are crucial to antibody binding. The novel MST method that is presented herein can be extended to the analysis of any ligand that is prone to degradation and can be applied not only to the development of vaccines to substances of abuse but also to the analysis of small molecule/protein interactions in the presence of serum.

Graphical abstract

The assessment and management of pain in cirrhosis

Purpose of review

The treatment of pain in patients with cirrhosis is complicated by unpredictable hepatic drug metabolism and a higher risk of adverse drug reactions. We aimed to conduct a scoping review regarding pain management in cirrhosis.

Recent findings

Despite the high prevalence of pain in patients with cirrhosis, there is little literature to guide the management of pain in this population. Complex pain syndromes and disease-specific pain etiologies exist are common in patients with cirrhosis. There are numerous contraindications and limitations when considering pharmacotherapy for analgesia in cirrhosis, specifically with non-steroidal anti-inflammatory drugs (NSAIDS) and opioid medications. Non-pharmacologic therapies for pain have not been specifically assessed in this population.

Summary

As with other populations, a multi-dimensional treatment approach to pain with a focus on physical, behavioral, procedural and pharmacologic treatment is recommended when caring for patients with cirrhosis and pain. However, more research is needed to evaluate opioid-sparing and non-pharmacologic analgesia in this population.

European Pain Federation position paper on appropriate opioid use in chronic pain management

Poorly controlled pain is a global public health issue. The personal, familial and societal costs are immeasurable. Only a minority of European patients have access to a comprehensive specialist pain clinic. More commonly the responsibility for chronic pain management and initiating opioid therapy rests with the primary care physician and other non‐specialist opioid prescribers. There is much confusing and conflicting information available to non‐specialist prescribers regarding opioid therapy and a great deal of unjustified fear is generated. Opioid therapy should only be initiated by competent clinicians as part of a multi‐faceted treatment programme in circumstances where more simple measures have failed. Throughout, all patients must be kept under close clinical surveillance. As with any other medical therapy, if the treatment fails to yield the desired results and/or the patient is additionally burdened by an unacceptable level of adverse effects, the overall management strategy must be reviewed and revised. No responsible clinician will wish to pursue a failed treatment strategy or persist with an ineffective and burdensome treatment. In a considered attempt to empower and inform non‐specialist opioid prescribers, EFIC convened a European group of experts, drawn from a diverse range of basic science and relevant clinical disciplines, to prepare a position paper on appropriate opioid use in chronic pain. The expert panel reviewed the available literature and harnessed the experience of many years of clinical practice to produce these series of recommendations. Its success will be judged on the extent to which it contributes to an improved pain management experience for chronic pain patients across Europe.

Significance

This position paper provides expert recommendations for primary care physicians and other non‐ specialist healthcare professionals in Europe, particularly those who do not have ready access to specialists in pain medicine, on the safe and appropriate use of opioid medications as part of a multi‐faceted approach to pain management, in properly selected and supervised patients.

Assessing the Impact of Renal Function on Trajectory of Intravenous Patient-controlled Analgesic Demands Over Time After Open and Laparoscopic Colorectal Surgery Using Latent Curve Analysis

OBJECTIVES

Intravenous patient-controlled analgesia (IVPCA) is often used to relieve pain after colorectal surgery. This study aimed to model the trajectory of analgesic demand over time after colorectal cancer surgery and explore potentially relevant influential factors using latent curve analysis, focusing on laparoscopic-assisted surgery and renal function.

MATERIALS AND METHODS

Patients receiving colorectal surgery with postoperative IVPCA were randomly divided into 2 equal parts to enable model construction and cross validation. Archived data were retrieved from the IVPCA pump. Latent curve modeling with 2 latent variables that reflected the baseline and slope of IVPCA demand trajectory over time was used and the effects of potentially influential factors on the 2 latent variables were evaluated. Goodness-of-fit indices were used to assess the model fit to both the model construction and validation data sets.

RESULTS

Data were collected from 834 patients, of whom 112 had laparoscopic-assisted surgery. Latent curve analysis revealed that body weight increased the baseline analgesic demand over time, whereas increasing age, female sex, poor renal function, and laparoscopic-assisted surgery decrease it. By contrast, only age and weight exerted significant effects on the slope parameter to modify the trajectory of IVPCA demand. Patients with higher age or less weight tended to have a smoother decreasing trajectory of analgesic demands over time. There was good cross validation, as the parameter estimates derived from the model construction data set fitted well to the validation data set (root mean square error of approximation: 0.05).

CONCLUSION

Laparoscopic-assisted surgery and renal function affected the baseline trajectory of IVPCA demand over time, but had no significant effect on its shape.

Correction to: Pharmacokinetics of Fentanyl and Its Derivatives in Children: A Comprehensive Review

Fentanyl and its derivatives sufentanil, alfentanil, and remifentanil are potent opioids. A comprehensive review of the use of fentanyl and its derivatives in the pediatric population was performed using the National Library of Medicine PubMed. Studies were included if they contained original pharmacokinetic parameters or models using established routes of administration in patients younger than 18 years of age. Of 372 retrieved articles, 44 eligible pharmacokinetic studies contained data of 821 patients younger than 18 years of age, including more than 46 preterm infants, 64 full-term neonates, 115 infants/toddlers, 188 children, and 28 adolescents. Underlying diagnoses included congenital heart and pulmonary disease and abdominal disorders. Routes of drug administration were intravenous, epidural, oral-transmucosal, intranasal, and transdermal. Despite extensive use in daily clinical practice, few studies have been performed. Preterm and term infants have lower clearance and protein binding. Pharmacokinetics was not altered by chronic renal or hepatic disease. Analyses of the pooled individual patients' data revealed that clearance maturation relating to body weight could be best described by the Hill function for sufentanil (R ² = 0.71, B _max 876 mL/min, K ₅₀ 16.3 kg) and alfentanil (R ² = 0.70, B _{max (fixed)} 420 mL/min, K ₅₀ 28 kg). The allometric exponent for estimation of clearance of sufentanil was 0.99 and 0.75 for alfentanil clearance. Maturation of remifentanil clearance was described by linear regression to bodyweight (R ² = 0.69). The allometric exponent for estimation of remifentanil clearance was 0.76. For fentanyl, linear regression showed only a weak correlation between clearance and bodyweight in preterm and term neonates (R ² = 0.22) owing to a lack of data in older age groups. A large heterogeneity regarding study design, clinical setting, drug administration, laboratory assays, and pharmacokinetic estimation was observed between studies introducing bias into the analyses performed in this review. A limitation of this review is that pharmacokinetic data, based on different modes of administration, dosing schemes, and parameter estimation methods, were combined.