Impact of CYP2D6*2, CYP2D6*35, rs5758550, and related haplotypes on risperidone clearance in vivo

PURPOSE

The CYP2D6 gene exhibits significant polymorphism, contributing to variability in responses to drugs metabolized by CYP2D6. While CYP2D6*2 and CYP2D6*35 are presently designated as alleles encoding normal metabolism, this classification is based on moderate level evidence. Additionally, the role of the formerly called "enhancer" single nucleotide polymorphism (SNP) rs5758550 is unclear. In this study, the impacts of CYP2D6*2, CYP2D6*35 and rs5758550 on CYP2D6 activity were investigated using risperidone clearance as CYP2D6 activity marker.

METHODS

A joint parent-metabolite population pharmacokinetic model was used to describe 1,565 serum concentration measurements of risperidone and 9-hydroxyrisperidone in 512 subjects. Risperidone population clearance was modeled as the sum of a CYP2D6-independent clearance term and the partial clearances contributed from each individually expressed CYP2D6 allele or haplotype. In addition to the well-characterized CYP2D6 alleles (*3-*6, *9, *10 and *41), *2, *35 and two haplotypes assigned as CYP2D6*2-rs5758550G and CYP2D6*2-rs5758550A were evaluated.

RESULTS

Each evaluated CYP2D6 allele was associated with significantly lower risperidone clearance than the reference normal function allele CYP2D6*1 (p < 0.001). Further, rs5758550 differentiated the effect of CYP2D6*2 (p = 0.005). The haplotype-specific clearances for CYP2D6*2-rs5758550A, CYP2D6*2-rs5758550G and CYP2D6*35 were estimated to 30%, 66% and 57%, respectively, relative to the clearance for CYP2D6*1. Notably, rs5758550 is in high linkage disequilibrium (R2 > 0.85) with at least 24 other SNPs and cannot be assigned as a functional SNP.

CONCLUSION

CYP2D6*2 and CYP2D6*35 encode reduced risperidone clearance, and the extent of reduction for CYP2D6*2 is differentiated by rs5758550. Genotyping of these haplotypes might improve the precision of genotype-guided prediction of CYP2D6-mediated clearance.

Dose Recommendations for Common Drugs in Patients with Liver Cirrhosis: A Systematic Literature Review

BACKGROUND AND OBJECTIVES

The presence of liver cirrhosis affects the selection and dosing of drugs metabolised by the liver as doses have to be adjusted to the remaining liver function. This is a major challenge in clinical practice as specific guidelines are lacking. The aim of this study was to identify drugs for which recommendations on selection and dose adjustments for patients with cirrhosis exist by assessing the literature according to certain quality standards, paying particular attention to the suitability of these recommendations for clinical practice.

METHODS

A systematic literature review included peer-reviewed publications that were published by October 2020 in PubMed in the English language and aimed to generate recommendations on dose adjustment in patients with liver cirrhosis. Subsequently, the identified publications were checked for reporting quality against the relevant reporting guidelines and the Oxford Centre for Evidence-Based Medicine Levels of Evidence. Finally, all specific dose recommendations were extracted, compared with the specifications of the Summaries of Product Characteristics and mapped according to the Anatomical Therapeutic Chemical/Defined Daily Dose Index.

RESULTS

Eighteen publications covering a total of 1145 dose recommendations for 481 active substances were identified. There were 706 recommendations for 316 substances sufficiently specific for application in clinical practice. For 22 active substances, the specific recommendations were consistent across multiple publications, of which only six were also consistent with the respective Summaries of Product Characteristics.

CONCLUSIONS

As the majority of dose recommendations were not sufficiently specific or even contradictory, there is an urgent need for the definition of standard parameters for a uniform assessment of drugs in liver cirrhosis. In addition, dose recommendations should be aligned by suitable methods.

Symptom Management in Patients with Cirrhosis: a Practical Guide

Purpose of the review

Though it is well known that cirrhosis is associated with significant morbidity and mortality, management of symptoms in cirrhosis can be difficult. This review serves to offer practical guidance in the management of liver-specific symptoms of cirrhosis as well as other symptoms with special hepatic considerations.

Recent findings

We discuss liver-specific symptoms and management, including ascites and refractory ascites, hepatic encephalopathy, pruritus, and muscle cramping. We also discuss the challenges of treating more generalized symptoms in cirrhosis, including pain, depression/anxiety, appetite, and fatigue. Medication management is, especially complex in this population given the altered metabolism of drugs, and we consider some strategies to approach this.

Summary

With the right tools, provided throughout this review, hepatologists should be well equipped to manage the nuanced liver-specific and generalized symptoms in patients with cirrhosis.

Improving Medication-Related Outcomes in Chronic Liver Disease

Patients with chronic liver disease (CLD) are becoming increasingly complex due to the rising prevalence of multimorbidity and polypharmacy. Medications are often essential to manage the underlying liver disease, complications of cirrhosis and portal hypertension, and comorbidities. However, medication-related problems (MRPs) have been associated with adverse patient outcomes, including hospitalization and mortality. Factors that can contribute to MRPs in people with CLD are variable and often entwined. This narrative literature review discusses key barriers and opportunities to modify risk factors and improve medication-related outcomes for people with CLD.

Development and Application of an UHPLC-MS/MS Method for Comparative Pharmacokinetic Study of Eight Major Bioactive Components from Yin Chen Hao Tang in Normal and Acute Liver Injured Rats

Yin Chen Hao Tang (YCHT) is one of the most famous hepatoprotective herbal formulas in China, but its pharmacokinetic investigation in model rats has been rarely conducted. In this study, the hepatic injury model was caused by intraperitoneal injections of carbon tetrachloride (CCl₄), and YCHT was orally administered to the model and normal rats. An ultrahigh performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was established to analyze the plasma pharmacokinetics of eight major bioactive ingredients from YCHT in both the normal and liver injured rats. The calibration curves presented good linearity (r > 0.9981) in the concentration range. The relative standard deviation (RSD%) of inter- and intraday precision was within 9.55%, and the accuracy (RE%) ranged from -10.72% to 2.46%. The extraction recovery, matrix effect, and stability were demonstrated to be within acceptable ranges. The lower limit of detection (LLOD) and lower limit of quantitation (LLOQ) were around 0.1 ng/mL and 0.5 ng/mL, respectively, which were much lower than those in other related researches. Results reveal that there are significant differences in the pharmacokinetics of scoparone, geniposide, rhein, aloe-emodin, physcion, and chrysophanol in hepatic injured rats as compared to those in control except for scopoletin and emodin. Our experimental results provide a meaningful reference for the clinical dosage of YCHT in treating liver disorders, and the improvement of LLOD and LLOQ can also broaden the range of our method's application, which is very suitable for quantitating these eight compounds with low levels.

Evidence-Based Recommendations to Improve the Safe Use of Drugs in Patients with Liver Cirrhosis

Introduction

The presence of liver cirrhosis can have a major impact on pharmacodynamics and pharmacokinetics, but guidance for prescribing is lacking.

Objective

The aim of this study is to provide an overview of evidence-based recommendations developed for the safe use of drugs in liver cirrhosis.

Methods

Recommendations were based on a systematic literature search combined with expert opinion from a panel of 10 experts. The safety of each drug was classified as safe, no additional risks known, additional risks known, unsafe, unknown or the safety class was dependent on the severity of liver cirrhosis (Child–Pugh classification). If applicable, drug-specific dosing advice was provided. All recommendations were implemented in clinical decision support systems and on a website.

Results

We formulated 218 recommendations for a total of 209 drugs. For nine drugs, two recommendations were formulated for different administration routes or indications. Drugs were classified as ‘safe’ in 29 recommendations (13.3%), ‘no additional risks known’ in 60 (27.5%), ‘additional risks known’ in 3 (1.4%), and ‘unsafe’ in 30 (13.8%). In 57 (26.1%) of the recommendations, safety depended on the severity of liver cirrhosis and was ‘unknown’ in 39 (17.9%) recommendations. Large alterations in pharmacodynamics were the main reason for classifying a drug as ‘unsafe’. For 67 drugs (31%), a dose adjustment was needed.

Conclusions

Over 200 recommendations were developed for the safe use of drugs in patients with liver cirrhosis. Implementing these recommendations into clinical practice can possibly enhance medication safety in this vulnerable patient group.

Electronic supplementary material

The online version of this article (10.1007/s40264-017-0635-x) contains supplementary material, which is available to authorized users.

Evaluating the safety and dosing of drugs in patients with liver cirrhosis by literature review and expert opinion

INTRODUCTION

Liver cirrhosis can have a major impact on drug pharmacokinetics and pharmacodynamics. Patients with cirrhosis often suffer from potentially preventable adverse drug reactions. Guidelines on safe prescribing for these patients are lacking. The aim of this study is to develop a systematic method for evaluating the safety and optimal dosage of drugs in patients with liver cirrhosis.

METHODS AND ANALYSIS

For each drug, a six-step evaluation process will be followed. (1) Available evidence on the pharmacokinetics and safety of a drug in patients with liver cirrhosis will be collected from the Summary of Product Characteristics (SmPC) and a systematic literature review will be performed. (2) Data regarding two outcomes, namely pharmacokinetics and safety, will be extracted and presented in a standardised assessment report. (3) A safety classification and dosage suggestion will be proposed for each drug. (4) An expert panel will discuss the validity and clinical relevance of this suggested advice. (5) Advices will be implemented in all relevant Clinical Decision Support Systems in the Netherlands and published on a website for patients and healthcare professionals. (6) The continuity of the advices will be guaranteed by a yearly check of new literature and comments on the advices. This protocol will be applied in the evaluation of a selection of drugs: (A) drugs used to treat (complications of) liver cirrhosis, and (B) drugs frequently prescribed to the general population.

ETHICS AND DISSEMINATION

Since this study does not directly involve human participants, it does not require ethical clearance. Besides implementation on a website and in clinical decision support systems, we aim to publish the generated advices of one or two drug classes in a peer-reviewed journal and at conference meetings.

Pharmacokinetics of antidepressants in patients with hepatic impairment

Appropriate use of antidepressant in patients with hepatic impairment requires careful consideration of how the hepatic illness may affect pharmacokinetics. This review aims to analyze pharmacokinetic profile, plasma level variations so as the metabolism of several antidepressants relating to their use in patients with an hepatic impairment. Due to the lack of data regarding hepatic impairment itself, the review is focused mainly on studies investigating pharmacokinetics in hepatic cirrhosis or alcohol-related conditions. More data on reduced hepatic metabolism can be extrapolated by drug studies conducted in elderly populations. Dose adjustment of antidepressants in these patients is important as most of these drugs are predominantly metabolized by the liver and many of them are associated with dose-dependent adverse reactions. As no surrogate parameter is available to predict hepatic metabolism of drugs, dose adjustment according to pharmacokinetic properties of the drugs is proposed. There is a need for a more balanced assessment of the benefits and risks associated with antidepressants use in patients with hepatic impairment, particularly considering pharmacokinetic profile of the drugs to ensure that patients, who would truly benefit from these agents, are not denied appropriate treatment. In conclusion, kinetic studies for centrally acting drugs including antidepressants with predominant hepatic metabolism should be carried out in patients with liver disease to allow precise dose recommendations for enhanced patient safety.

Safety of paliperidone extended-release in patients with schizophrenia or schizoaffective disorder and hepatic disease

BACKGROUND/PURPOSE

Patients with schizophrenia often suffer from comorbid hepatic disease. This multicenter, open-label, single-arm, crossover study evaluated the safety and efficacy of paliperidone extended-release (ER) in patients with schizophrenia or schizoaffective disorder and hepatic disease.

METHODS

The study comprised a screening period, followed by 9 weeks' open-label treatment, divided into 2 phases. Phase 1 (4 weeks) was a continuation of usual antipsychotic treatment (UAT); phase 2 (5 weeks) consisted of a 1-week cross-titration from UAT to flexibly dosed paliperidone ER (3-12 mg/d), followed by 4 weeks of paliperidone ER alone. Treatment-emergent adverse events (TEAEs), including those considered more relevant to antipsychotic treatment (prespecified adverse events [AEs]), were analyzed.

RESULTS

Although more subjects reported TEAEs during the paliperidone ER alone period than during the UAT period, no significant differences occurred in prespecified AE rates. No new safety signals were detected, and minimal shifts in liver function test values were observed. Improvements in psychiatric symptoms and functioning were observed after 4 weeks' paliperidone ER treatment.

CONCLUSIONS

This study suggests that paliperidone ER is well tolerated in patients with schizophrenia or schizoaffective disorder and hepatic disease. To the best of our knowledge, this is the largest prospective study to date in this population.

Review article: depression and the use of antidepressants in patients with chronic liver disease or liver transplantation

BACKGROUND

The scale of depression in patients with chronic liver disease (CLD) and those who have received orthotopic liver transplantation (OLT) is poorly characterised. Clinicians are uncertain of how best to manage depression within these patients.

AIMS

To review the literature evaluating both the prevalence and impact of depression in patients with CLD and post-OLT, and to assess the safety and efficacy of antidepressant use within this context.

METHODS

A PubMed search using the phrases 'chronic liver disease', 'cirrhosis', 'liver transplantation', 'depression', 'antidepressant' and the names of specific causes of liver disease and individual antidepressants.

RESULTS

Over 30% of cirrhotic patients have depressive features, and they experience worse clinical outcomes than nondepressed cirrhotic patients. CLD patients with chronic hepatitis C are particularly prone to depression, partly related to the use of interferon therapy. OLT patients with depression have higher mortality rates than nondepressed patients; appropriate antidepressant use reverses this effect. Selective serotonin reuptake inhibitors (SSRIs) and selective noradrenaline reuptake inhibitors (SNRIs) are effective and generally safe in both CLD and OLT patients.

CONCLUSIONS

Depression is much more prevalent in CLD or OLT patients than is generally recognised, and it adversely affects clinical outcomes. The reasons for this relationship are complex and multifactorial. Antidepressants are effective in both CLD and post-OLT, although lower doses or a reduced dosing frequency may be required to minimise side effects, e.g. exacerbation of hepatic encephalopathy. Further research is needed to establish optimal management of depression in these patients, including the potential role of nonpharmacological treatments.

A study of the relationship between serum bile acids and propranolol pharmacokinetics and pharmacodynamics in patients with liver cirrhosis and in healthy controls

The main objectives of the study were to determine the exposure and bioavailability of oral propranolol and to investigate their associations with serum bile acid concentration in patients with liver cirrhosis and in healthy controls. A further objective was to study the pharmacodynamics of propranolol. An open-label crossover study was performed to determine the pharmacokinetics and pharmacodynamics of propranolol after oral (40 mg) and intravenous (1 mg) administration as well as the concentration of total and individual fasting serum bile acids in 15 patients with liver cirrhosis and 5 healthy controls. After intravenous propranolol, patients showed a 1.8-fold increase in the area under the plasma concentration-time curve (AUC_0–∞), a 1.8-fold increase in volume of distribution and a 3-fold increase in the elimination half-life (mean ± SEM: 641±100 vs. 205±43 minutes) compared to controls. After oral application, AUC_0–∞ and elimination half-life of propranolol were increased 6- and 4-fold, respectively, and bioavailability 3-fold (83±8 vs. 27±9.2%). Maximal effects on blood pressure and heart rate occurred during the first 4 and first 2 hours, respectively, after intravenous and oral application in both patients and controls. Total serum bile acid concentrations were higher in patients than controls (42±11 vs. 2.7±0.3 µmol/L) and were linearly correlated with the serum chenodeoxycholic acid concentration. There was a linear correlation between the SBA concentration and propranolol oral AUC_0–∞ in subjects not receiving interacting drugs (r² = 0.73, n = 18). The bioavailability of and exposure to oral propranolol are increased in patients with cirrhosis. Fasting serum bile acid concentration may be helpful in predicting the exposure to oral propranolol in these patients.

Medication prescribing in liver dysfunction

Patients with mental illness often have co-occurring substance abuse which increases the risk for developing cirrhosis, particularly with common etiologies such as hepatitis and alcoholic liver disease. As such, knowledge of how the disease may impact medication prescribing is important. Unfortunately, there is a paucity of data to guide medication prescribing in these patients. Product labeling information should be used in the clinical decision making process. Additionally, clinicians should consider the etiology of disease, adverse effect profile, and pharmacokinetic parameters including solubility, product formulation, protein binding, hydrophilicity, metabolism, bioavailability, extraction ratios, excretion route, and half-life. Thoughtful consideration should be given when prescribing potentially hepatotoxic medications, and those which may increase bleeding risk in patients with coagulopathy. It is essential to ensure every medication has an appropriate indication and carefully evaluate the need for each medication. Overall, more research is necessary to support clinical decision-making with outcomes based research in patients with chronic liver disease.

Review article: prescribing medications in patients with cirrhosis - a practical guide

BACKGROUND

Most drugs have not been well studied in cirrhosis; recommendations on safe use are based largely on experience and/or expert opinion, with dosing recommendations often based on pharmacokinetic (PK) changes.

AIM

To provide a practical approach to prescribing medications for cirrhotic patients.

METHODS

An indexed MEDLINE search was conducted using keywords cirrhosis, drug-induced liver injury, pharmacodynamics (PDs), PKs, drug disposition and adverse drug reactions. Unpublished information from the Food and Drug Administration and industry was also reviewed.

RESULTS

Most medications have not been adequately studied in cirrhosis, and specific prescribing information is often lacking. Lower doses are generally recommended based on PK changes, but data are limited in terms of correlating PD effects with the degree of liver impairment. Very few drugs have been documented to have their hepatotoxicity potential enhanced by cirrhosis; most of these involve antituberculosis or antiretroviral agents used for HIV or viral hepatitis. Paracetamol can be used safely when prescribed in relatively small doses (2-3 g or less/day) for short durations, and is recommended as first-line treatment of pain. In contrast, NSAIDs should be used cautiously (or not at all) in advanced cirrhosis. Proton pump inhibitors have been linked to an increased risk of spontaneous bacterial peritonitis (SBP) in cirrhosis and should be used with care.

CONCLUSIONS

Most drugs can be used safely in cirrhosis, including those that are potentially hepatotoxic, but lower doses or reduced dosing frequency is often recommended, due to altered PKs. Drugs that can precipitate renal failure, gastrointestinal bleeding, SBP and encephalopathy should be identified and avoided.

Cognitive dysfunction in cirrhosis is associated with falls: a prospective study

Falls are frequent among patients with debilitating disorders and can have a serious effect on health status. Mild cognitive disturbances associated with cirrhosis may increase the risk for falls. Identifying subjects at risk may allow the implementation of preventive measures. Our aim was to assess the predictive value of the Psychometric Hepatic Encephalopathy Score (PHES) in identifying patients likely to sustain falls. One hundred and twenty-two outpatients with cirrhosis were assessed using the PHES and were followed at specified intervals. One third of them exhibited cognitive dysfunction (CD) according to the PHES (<-4). Seventeen of the forty-two patients (40.4%) with CD had at least one fall during follow-up. In comparison, only 5 of 80 (6.2%) without CD had falls (P < 0.001). Fractures occurred in 4 patients (9.5%) with CD, but in no patients without CD (P = 0.01). Patients with CD needed more healthcare (23.8% versus 2.5%; P < 0.001), more emergency room care (14.2% versus 2.5%; P = 0.02), and more hospitalization (9.5% versus 0%; P = 0.01) as a result of falls than patients without CD. Patients taking psychoactive treatment (n = 21) had a higher frequency of falls, and this was related to an abnormal PHES. In patients without psychoactive treatment (n = 101), the incidence of falls was 32.4% in patients with CD versus 7.5% in those without CD (P = 0.003). In the multivariate analysis, CD was the only independent predictive factor of falls (odds ratio, 10.2; 95% confidence interval, 3.4-30.4; P < 0.001). The 1-year probability of falling was 52.3% in patients with CD and 6.5% in those without (P < 0.001).

CONCLUSION

An abnormal PHES identifies patients with cirrhosis who are at risk for falls. This psychometric test may be useful to promote awareness of falls and identify patients who may benefit from preventive strategies.

Minimal hepatic encephalopathy is associated with falls

OBJECTIVES

Minimal hepatic encephalopathy (MHE) reduces quality of life and impacts daily functioning. It is known to impair fitness to drive, but deficits in attention and reaction may also be associated with falls. Falls may have important consequences in patients with cirrhosis due to coagulopathy, osteoporosis, and operative risk. However, the relationship between MHE and falls has not yet been evaluated. The objective of this study is to retrospectively investigate whether MHE is associated with falls in patients with cirrhosis.

METHODS

We included 130 cirrhotic outpatients and 43 controls. MHE was diagnosed according to the results of the psychometric hepatic encephalopathy score (PHES). We recorded the reported incidence and number of falls in the 12 months before the study, the severity of injuries, and the need for healthcare services.

RESULTS

Forty-five (34.6%) patients with cirrhosis exhibited MHE. The proportion of patients with MHE that reported falls (40%) was higher than those without MHE (12.9%, P<0.001), which was similar to controls (11.6%). In patients with MHE, there was a higher need for primary healthcare services (8.8 vs. 0%, P=0.004) and hospitalization (6.6 vs. 2.3%, P=0.34) due to falls than in patients without MHE. Patients on psychoactive drugs (n=21) showed a stronger association between MHE and falls: 6/8 (75%) patients with MHE presented falls vs. 2/13 (15.3%) patients without MHE (P=0.01). In patients not receiving psychoactive drugs (n=109), the incidence of falls was 12/37 (32.4%) in patients with MHE vs. 9/72 (12.5%) in those without MHE (P=0.01). Multivariate analysis showed that MHE (odds ratio (OR): 2.91, 95% confidence interval (CI): 1.13-7.48, P=0.02), previous encephalopathy (OR: 2.87, 95% CI: 1.10-7.50, P=0.03), and antidepressant therapy (OR: 3.91, 95% CI: 0.96-15.9, P=0.05) were independent factors associated to previous falls.

CONCLUSIONS

Falls are more frequent in cirrhotic patients with MHE, particularly in those on treatment with psychoactive drugs, and are a significant cause for healthcare and hospitalization requirements.

Integral pharmacokinetics of multiple lignan components in normal, CCl4-induced hepatic injury and hepatoprotective agents pretreated rats and correlations with hepatic injury biomarkers

Although pharmacokinetic alternations by hepatic injury have been extensively studied, little is known about the potential influence of hepatoprotective agent's treatment. This study was aimed to investigate the holistic pharmacokinetics of multiple lignans, CYP3A regulations, and their correlations with hepatic injury biomarkers, in hepatic injured rats pretreated with or without schisandra lignan extract (SLE) and dimethyl-diphenyl-bicarboxylate (DDB). Integral pharmacokinetics of multiple lignans based on an AUC-weighting approach was determined in normal, CCl4 induced hepatic injury rats pretreated with or without SLE and DDB. Protein expression and activities of CYP3A were determined. Pharmacokinetic parameters and CYP3A activities were correlated with serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels. CCl4 induced acute hepatic injury resulted in a nearly 8-fold enhancement of integral plasma exposures of multiple lignans, which was caused by the significant down-regulation of CYP3A. SLE and DDB pretreatment exhibited potent hepatoprotective effects, accompanied with the restored expression and activity of CYP3A, and the recovery of the respective and integral pharmacokinetics of lignans components. The integral AUC(0-tn) and CYP3A activities correlated well with ALT and AST. This study suggested that the pharmacokinetic regulating effects of hepatoprotective agent's on themselves and co-prescribed drugs should be of concern, and hepatic injury biomarkers may serve as good predictors.