Acute liver and renal failure during treatment with buprenorphine at therapeutic dose

Buprenorphine affects the initiation and severity of interleukin-induced acute pancreatitis in mice

Acute pancreatitis (AP) is a common disease with no targeted therapy and has varied outcomes ranging from spontaneous resolution to being lethal. Although typically painful, AP can also be painless. Various agents, including opioids, are used for pain control in AP; the risks and benefits of which are often debated. As experimental AP in mice is used to study the efficacy of potential therapies, we studied the effect of a commonly used opioid, buprenorphine, on the initiation and progression of AP. For this, we administered extended-release buprenorphine subcutaneously before inducing the previously established severe AP model that uses interleukins 12 and 18 (IL12,18) in genetically obese (ob/ob) mice and compared this to mice with AP but without the drug. Mice were monitored over 3 days, and parameters of AP induction and progression were compared. Buprenorphine significantly reduced serum amylase, lipase, pancreatic necrosis, and AP-associated fat necrosis, which is ubiquitous in obese mice and humans. Buprenorphine delayed the AP-associated reduction of carotid artery pulse distention and the development of hypothermia, hastened renal injury, and muted the early increase in respiratory rate versus IL12,18 alone. The site of buprenorphine injection appeared erythematous, inflamed, and microscopically showed thinning, loss of epidermal layers that had increased apoptosis. In summary, subcutaneous extended-release buprenorphine interfered with the induction of AP by reducing serum amylase, lipase, pancreatic and fat necrosis, the worsening of AP by delaying hypotension, hypothermia, while hastening renal injury, respiratory depression, and causing cutaneous injury at the site of injection.NEW & NOTEWORTHY Extended-release buprenorphine interferes with the initiation and progression of acute pancreatitis at multiple levels.

Evaluation of the Hepatotoxicity of Buprenorphine in Rat Pups Born to an Exposed Mother During Lactation

AIMS

This study aimed to evaluate the hepatotoxicity of buprenorphine in lactating rat pups of buprenorphine-injected mothers. Buprenorphine (BUP), a semisynthetic opioid, is increasingly administrated as a first-line standard maintenance treatment for opioid dependence due to its high safety and efficacy compared to other opioids. Numerous studies have confirmed the safety of BUP maintenance treatment in addicted patients.

OBJECTIVES

This study was designed to assess the effects of BUP on the activities of liver enzymes, oxidative parameters, and liver histopathological changes in pups born to a mother exposed to this drug during lactation.

METHODS

BUP at a dose of 0.5 or 0.1 mg/kg was subcutaneously administrated to lactating rats for 28 days. At the end of the experiment, the pups were anesthetized, and blood samples were obtained from their hearts for measuring liver enzymes. Then the livers of the animals were dissected to measure oxidative stress parameters. In addition, the liver samples were fixed for histopathological evaluation.

RESULTS

The findings indicated a decrease in the activities of serum liver enzymes (ALT and AST) of the pups born to mothers exposed to 0.5 and 1 mg/kg of BUP during lactation. BUP could not change malondialdehyde (MDA), glutathione (GSH), nitric oxide (NO) levels, nor superoxide dismutase (SOD) activity in the liver tissue of animals. Some vacuolated hepatocytes with dark, eccentric nuclei, necrosis with karyolytic nuclei, mitotic figures, and multiple binucleated cells were seen in the pups which received 1 mg/kg of BUP.

CONCLUSION

In conclusion, BUP may induce liver dysfunction in pups born to mothers exposed to this drug during lactation.

Buprenorphine administration during gestation induces hepatotoxicity in the rat fetus

This study investigated the effect of buprenorphine (BUP) on the livers of pups exposed to this drug during the fetal stage. BUP decreased the activities of serum liver enzymes in exposed animals versus the controls. BUP (0.5 mg/kg) decreased malondialdehyde levels and increased the glutathione levels in the liver of animals versus other groups. The superoxide dismutase activity was elevated in the BUP 0.5 mg/kg group versus the control group. BUP (1 mg/kg) induced histopathological changes in the livers of pups. In conclusion, BUP may induce hepatotoxicity in pups exposed to this drug during the fetal stage.

A ternary nanocomposite based on nickel(iii) oxide@f-CNF/rGO for efficient electrochemical detection of an antipsychotic drug (Klonopin) in biological samples

The formation of the Ni₂O₃@f-CNF/rGO composite for the electrochemical detection of KNP.

A relative study on sonochemically synthesized mesoporous WS2 nanorods & hydrothermally synthesized WS2 nanoballs towards electrochemical sensing of psychoactive drug (Clonazepam)

In this paper, mesoporous tungsten sulfide electrocatalyst (MP-WS₂) were developed through a facile sonochemical technique (SC) and utilized as an electrocatalyst for the sensitive electrochemical detection of Psychoactive drug. The as-prepared SC-MP-WS₂ NRs and HT-WS₂ NPs (hydrothermally synthesized) were characterized using XRD, Raman, XPS, FESEM, HRTEM, BET, EDX, and electrochemical analysis, which exposed the formation of WS₂ in the form of mesoporous nanorods in shape. Further, the use of the as-developed SC-MP-WS₂ NRs and HT-WS₂ NPs as an electrocatalyst for the detection of clonazepam (CNP). Interestingly, the SC-MP-WS₂ NRs modified screen-printed carbon electrode (SC-MP-WS₂ NRs/SPCE) exhibited an excellent electrocatalytic performance, and enhanced reduction peak current when compared to HT-WS₂ NPs with unmodified electrode. Moreover, as-prepared SC-MP-WS₂ NRs/SPCE displayed wide linear response range (10-551 µM), lower detection limit (2.37 nM) and high sensitivity (24.32 µAµM^-1cm^-2). Furthermore, SC-MP-WS₂ NRs/SPCE showed an excellent selectivity even in the existence of potentially co-interfering compounds. The proposed sensor was successfully applied for the determination of CNP in biological and drug samples with acceptable recovery.

Systematic review of nephrotoxicity of drugs of abuse, 2005-2016

BACKGROUND

The United States is faced with an unprecedented epidemic of drug abuse. Every year thousands of Americans visit the emergency departments all over the country with illicit drug related complaints. These drugs have been known to be associated with a range of renal pathologies, from reversible acute kidney injuries to debilitating irreversible conditions like renal infarction. So far, no comprehensive study or systematic review has been published that includes the commonly used street drugs and designer drugs with potential nephrotoxic outcomes.

METHODS

We conducted a systematic review of published case reports, case series, and cross sectional studies of nephrotoxicities related to drugs of abuse. Literature review was conducted using PubMed/Medline from January 1, 2005 -December 31, 2016 to search for publications related to drug abuse with a defined renal outcome. Publications which reported renal injury in relation to the use of illicit drugs were selected, specifically those cases with raised creatinine levels, clinically symptomatic patients, for instance those with oliguria and proven renal biopsies.

RESULTS

A total of 4798 publications were reviewed during the search process and PRISMA flow chart and Moose protocol regarding systematic reviews were followed. 110 articles were shortlisted for the review. A total of 169 cases from case reports and case series, and 14 case studies were analyzed. Renal manifestations of specific illicit drug abuse were included in this review.

CONCLUSION

Based on the evidence presented, a wide range of renal manifestations were found to be associated with drug abuse. If the trend of increasing use of illicit drug use continues, it will put a significant percentage of the population at an elevated risk for poor renal outcomes. This study is limited by the nature of the literature reviewed being primarily case reports and case series.

Hepatic Safety of Buprenorphine in HIV-Infected and Uninfected Patients With Opioid Use Disorder: The Role of HCV-Infection

INTRODUCTION

Individuals with HIV and hepatitis C (HCV) infection, alcohol use disorder, or who are prescribed potentially hepatotoxic medications may be at increased risk for buprenorphine (BUP) associated hepatotoxicity.

MATERIALS AND METHODS

We examined a cohort of HIV-infected and uninfected patients receiving an initial BUP prescription between 2003 and 2012. We compared changes in alanine and aspartate aminotransferases (ALT and AST) and total bilirubin (TB) stratified by HIV status. We identified cases of liver enzyme elevation (LEE), TB elevation (TBE), and conducted chart review to assess for cases of drug induced liver injury (DILI) and death. We examined associations between age, sex, race, HIV-infection, HCV-infection, alcohol use disorder, and prescription of other potentially heptatotoxic medications with the composite endpoint of LEE, TBE, and DILI.

RESULTS

Of 666 patients prescribed BUP, 36% were HIV-infected, 98% were male, 60% had RNA-confirmed HCV infection, 50% had a recent diagnosis of alcohol use disorder, and 64% were prescribed other potentially hepatotoxic medications. No clinically significant changes were observed in median ALT, AST and TB and these changes did not differ between HIV-infected and uninfected patients. Compared with uninfected patients, HIV-infected (OR 7.3, 95% CI 2.1-26.1, p=0.002), HCV-infected (OR 4.9 95% CI 1.6-15.2, p=0.007) or HIV/HCV co-infected patients (OR 6.9, 95%CI 2.1-22.2, p=0.001) were more likely to have the composite endpoint of LEE, TB elevation or DILI, in analyses that excluded 60 patients with evidence of pre-existing liver injury. 31 patients had LEE, 14/187 HIV-infected and 17/340 uninfected (p=0.25); 11 had TBE, including 9/186 HIV-infected and 2/329 uninfected (p=0.002); 8 experienced DILI, 4/202 HIV-infected and 4/204 uninfected (p=0.45). There were no significant associations with alcohol use disorder or prescription of other potentially hepatotoxic medications after adjustment for HIV/HCV status.

CONCLUSIONS

Liver enzymes and TB are rarely elevated in HIV-infected and uninfected patients receiving BUP. Risk of hepatotoxicity was greater in individuals infected with HIV, HCV, or HIV/HCV co-infection, who may benefit from increased monitoring.

Opioid Drugs in Patients With Liver Disease: A Systematic Review

CONTEXT

The liver, one of the most important organs of the body, is known to be responsible for several functions. The functional contribution of the liver to the metabolism of carbohydrates, protein, drugs and toxins, fats and cholesterol and many other biological processes are still unknown. Liver disorders are classified into two types: acute and chronic. Different drugs are used in liver diseases to treat and control pain. Most pain relief medications such as opioids are metabolized via the liver; therefore, the adverse reactions of drugs are probably higher for patients with liver disease. The current study aimed to evaluate the effects of opioid drugs on patients with liver disease; therefore, it is necessary to select suitable opioids for such patients.

EVIDENCE ACQUISITION

This review was written by referring to research literature including 70 articles and four textbooks published from 1958 to 2015 on various reputable sites. Searches were carried out on the key phrases of narcotic pain relievers (opioids), acute and chronic hepatic failure, opioid adverse drug reactions, drug-induced liver injury (DILI) and other similar keywords. References included a variety of research papers (descriptive and analytical), intervention and review articles.

RESULTS

In patients with liver disease, administration of opioid analgesics should be observed, accurately. As a general rule, lower doses of drugs should be administered at regular intervals based on the signs of drug accumulation. Secondly, the interactions of opioid drugs with different levels of substrates of the P450 cytochrome enzyme should be considered.

CONCLUSIONS

Pain management in patients with liver dysfunction is always challenging to physicians because of the adverse reactions of drugs, especially opioids. Opioids should be used cautiously since they can cause sedation, constipation and sudden encephalopathy effects. Since the clearance of these drugs in patients with hepatic insufficiency is decreased, the initial dose must be decreased, the intervals between doses should be increased and some patients need to be continuously assessed.

Fulminant hepatic failure after intravenous injection of sublingual buprenorphine in a patient with hepatitis C

A 20-year-old indigenous Australian male was admitted to the intensive care unit with fulminant hepatic failure secondary to intravenous use of buprenorphine, which had been prescribed sublingually for opioid dependence. Intravenous buprenorphine-induced hepatitis is well recognized, however, life-threatening fulminant hepatic failure has not previously been reported.

Liver enzyme levels in adolescent patients treated with buprenorphine and additional psychotropic agents

BACKGROUND

There are limited efficacy and safety data for buprenorphine/naloxone treatment in adolescents, and little is known about the incidence and prevalence of liver function abnormalities in young patients using buprenorphine/naloxone.

OBJECTIVES

To assess the changes in liver enzyme levels associated with buprenorphine/naloxone treatment and co-medication with psychotropic agents among opioid dependent subjects aged 15-18 years.

METHODS

Liver enzyme levels (ALT and AST) were evaluated among 59 adolescent subjects before and following eight weeks of buprenorphine/naloxone treatment.

RESULTS

The frequency of additional psychotropic use was 60%. The patients' mean liver enzyme levels at weeks 2 and 4 were significantly higher than the baseline (ALT: p < 0.0001 and p = 0.003, and AST: p < 0.0001 and p = 0.016, respectively). However, there was no statistically significant difference in AST and ALT levels between the baseline and week 8. The majority of the abnormalities seen were clinically nonsignificant elevations (less than two times the upper limit of normal). It is plausible that the abnormalities in liver enzymes could have been mediated by the use of psychotropic medications.

CONCLUSIONS

Buprenorphine/naloxone was well tolerated in most adolescent patients, besides clinically nonsignificant liver enzyme elevations. Psychotropic medications may have been associated with the liver enzyme changes early in the course of treatment. Nevertheless, given the relatively small number of adolescents studied to date with buprenorphine/naloxone, additional studies evaluating liver enzymes in young patients receiving buprenorphine/naloxone (and no other psychotropics) are needed.

Opioid use and risk of liver fibrosis in HIV/hepatitis C virus-coinfected patients in Canada

OBJECTIVES

Opioid use and opioid-related mortality have increased dramatically since the 1990s in North America. The effect of opioids on the liver is incompletely understood. Some studies have suggested that opioids cause liver damage and others have failed to show any harm. HIV/hepatitis C virus (HCV)-coinfected persons may be particularly vulnerable to factors increasing liver fibrosis. We aimed to describe opioid use in an HIV/HCV-coinfected population in Canada and to estimate the association between opioid use and liver fibrosis.

METHODS

We conducted a cross-sectional descriptive analysis of the Canadian Co-infection Cohort Study data to characterize opioid use. We then conducted a longitudinal analysis to assess the average change in aspartate aminotransferase-to-platelet ratio index (APRI) score associated with opioid use using a generalized estimating equation with linear regression. We assessed the progression to significant liver fibrosis (APRI ≥ 1.5) associated with opioid use with pooled logistic regression.

RESULTS

In the 6 months preceding cohort entry, 32% of the participants had received an opioid prescription, 28% had used opioids illicitly and 18% had both received a prescription and used opioids illicitly. Neither prescribed nor illicit opioid use was associated with a change in the median APRI score [exp(β) 0.99 (95% confidence interval (CI) 0.82, 1.12) and exp(β) 0.95 (95% CI 0.81, 1.10), respectively] or with faster progression to liver fibrosis [hazard odds ratio (HOR) 1.20 (95% CI 0.73, 1.67) and HOR 1.09 (95% CI 0.63, 1.55), respectively].

CONCLUSIONS

Although opioids were commonly used both legally and illegally in our cohort, we were unable to demonstrate a negative impact on liver fibrosis progression.

Alcohol use disorders in opioid maintenance therapy: prevalence, clinical correlates and treatment

Maintenance therapy with methadone or buprenorphine is an established and first-line treatment for opioid dependence. Clinical studies indicate that about a third of patients in opioid maintenance therapy show increased alcohol consumption and alcohol use disorders. Comorbid alcohol use disorders have been identified as a risk factor for clinical outcome and can cause poor physical and mental health, including liver disorders, noncompliance, social deterioration and increased mortality risk. The effects of opioid maintenance therapy on alcohol consumption are controversial and no clear pattern has emerged. Most studies have not found a change in alcohol use after initiation of maintenance therapy. Methadone and buprenorphine appear to carry little risk of liver toxicity, but further research on this topic is required. Recent data indicate that brief intervention strategies may help reduce alcohol intake, but the existing evidence is still limited. This review discusses further clinical implications of alcohol use disorders in opioid dependence.

Buprenorphine-naloxone treatment in opioid dependence and risk of liver enzyme elevation: results from a 12-month observational study

BACKGROUND

Some case series mention possible liver toxicity in opioid-dependent patients under buprenorphine treatment.

METHODS

This 12-month prospective observational follow-up study in opioid-dependent patients under buprenorphine-naloxone treatment assessed outcome and safety issues. At baseline, 337 eligible datasets were available; 181 patients completed the 12-month study. Liver enzymes were tested at baseline and after 12, 24, and 52 weeks' treatment.

RESULTS

One to two percent of patients showed mostly discrete elevations of liver enzymes, but no patient met the criteria for drug-induced liver injury. No serious liver-related adverse events occurred, but two non-serious cases of liver enzyme increase were recorded. No patient dropped out of treatment for liver-related disorders.

CONCLUSION

This study is in line with some recent studies and provides further evidence that buprenorphine-naloxone is relatively safe with respect to liver injury.

Hepatotoxicity in a 52-week randomized trial of short-term versus long-term treatment with buprenorphine/naloxone in HIV-negative injection opioid users in China and Thailand

BACKGROUND

Buprenorphine/naloxone (BUP/NX), an effective treatment for opioid dependence, has been implicated in hepatic toxicity. However, as persons taking BUP/NX have multiple hepatic risk factors, comparative data are needed to quantify the risk of hepatoxicity with BUP/NX.

METHODS

We compared rates of alanine aminotransferase (ALT) elevation≥grade 3 (ALT≥5.1 times the upper limit of normal) and graded bilirubin elevations in HIV-negative opioid injectors randomized to long-term (52 weeks) or short-term (18 days) medication assisted treatment (LT-MAT and ST-MAT, respectively) with BUP/NX in a multisite trial conducted in China and Thailand. ALT and bilirubin were measured at baseline, 12, 26, 40 and 52 weeks, times temporally remote from BUP/NX exposure in the ST-MAT participants.

RESULTS

Among1036 subjects with at least one laboratory follow-up measurement, 76 (7%) participants experienced ALT elevation≥grade 3. In an intent-to-treat analysis, the risk of ALT events was similar in participants randomized to LT-MAT compared with ST-MAT (adjusted hazard ratio 1.25, 95% confidence interval 0.79 to 1.98). This finding was supported by an as-treated analysis, in which actual exposure to BUP/NX was considered. Hepatitis C seroconversion during follow-up was strongly associated with ALT events. Bilirubin elevations≥grade 2 occurred in 2% of subjects, with no significant difference between arms.

CONCLUSIONS

Over 52-week follow-up, the risk of hepatotoxicity was similar in opioid injectors receiving brief and prolonged treatment with BUP/NX. These data suggest that most hepatotoxic events observed during treatment with BUP/NX are due to other factors.

Buprenorphine in the treatment of opioid addiction: opportunities, challenges and strategies

INTRODUCTION

Buprenorphine follows the success of methadone as another milestone in the history of treatment for opioid addiction. Buprenorphine can be used in an office-based setting where it is clearly effective, highly accepted by patients and has a favorable safety profile and less abuse potential. However, the adoption of buprenorphine treatment has been slow in the USA.

AREAS COVERED

This article first reviews the history of medication-assisted opioid addiction treatment and the current epidemic opioid addiction, followed by a review of the efficacy, pharmacology and clinical prescription of buprenorphine in office-based care. We then explore the possible barriers in using buprenorphine and the ways to overcome these barriers, including new formulations, educational programs and policy regulations that strike a balance between accessibility and reducing diversion.

EXPERT OPINION

Buprenorphine can align addiction treatment with treatments for other chronic medical illnesses. However, preventing diversion will require graduate and continuing medical education and integrated care models for delivery of buprenorphine to those in need.

Buprenorphine for Cancer Pain

Buprenorphine (BUP) is a semisynthetic derivative of the opium alkaloid thebaine found in the poppy Papaver somniferum. Its chemical structure contains the morphine structure but differs by having a cyclopropylmethyl group. Buprenorphine is a potent µ opioid agonist. Buprenorphine undergoes extensive first-pass metabolism in the liver and gut. The development of a transdermal BUP formulation in 2001 led to its evaluation in cancer pain. This article provides the practitioner with an update on the current role of BUP in cancer care. It highlights data suggesting effectiveness in various types of cancer pain. The article reviews pharmacology, routes of administration, adverse effects, drug interactions, and cost considerations.

Acute hepatitis and renal failure related to intranasal buprenorphine misuse: case report and analysis of cases reported to the French network for drug monitoring

BACKGROUND

Rare cases of acute hepatitis have been reported following injection, overdose, and even during the use of buprenorphine (BPN) at therapeutic doses, especially in carriers of hepatitis C virus (HCV).

OBJECTIVES

To report a case of acute hepatitis and renal failure related to intranasal BPN misuse in a HCV-negative patient and to analyze cases reported to the French postmarketing surveillance system (PMSS) of drugs and in the literature.

METHODS

All cases of hepatitis related to BPN reported to PMSS between January 1996 and December 2012 were analyzed.

RESULTS

A 42-year-old man with a history of intranasal BPN misuse (8 mg/d) for at least 10 years was admitted for flu-like symptoms and abdominal pain. At admission, the patient consumed alcohol, cannabis, and tobacco. Acute hepatitis and acute renal failure were diagnosed . Clinical signs and biological parameters resolved within 26 days. An objective causality assessment revealed that an adverse drug reaction (ADR) was possible. In the French PMSS database, 41 cases of suspected BPN-induced hepatitis are reported. In 36.6% of cases, BPN was misused by the intravenous route. In the literature, 16 cases of acute hepatitis related to BPN with or without renal failure are reported. In all cases, patients were HCV carriers. The primary mechanism of BPN-induced hepatitis is a mitochondrial dysfunction, exacerbated by cofactors (HCV, alcohol, and medications).

CONCLUSION

Intranasal misuse of BPN is increasingly frequent. We report here the first documented case of acute hepatitis and renal failure related to intranasal BPN misuse in a patient negative for HCV infection.

Effects of HCV seropositive status on buprenorphine pharmacokinetics in opioid-dependent individuals

BACKGROUND AND OBJECTIVES

The purpose of this study was to examine the effect of hepatitis C virus (HCV) infection on buprenorphine pharmacokinetics in opioid-dependent, buprenorphine/naloxone-maintained adults.

METHODS

A retrospective analysis of buprenorphine pharmacokinetics in HCV seropositive and seronegative buprenorphine/naloxone-maintained individuals (N = 49) was undertaken.

RESULTS

Relative to HCV seronegative subjects, HCV seropositive subjects had higher buprenorphine exposure, as demonstrated by elevated buprenorphine AUC and Cmax values (p = .03 and .02, respectively) and corresponding elevations in the metabolites, buprenorphine-3-glucuronide AUC values (p = .03) and norbuprenorphine-3-glucuronide AUC and C24 values (p = .05 and .03, respectively).

DISCUSSION AND CONCLUSIONS

HCV infection was associated with higher plasma concentrations of buprenorphine and buprenorphine metabolites.

SCIENTIFIC SIGNIFICANCE AND FUTURE DIRECTIONS

Findings suggest the potential for opioid toxicity among HCV-infected patients treated with buprenorphine/naloxone, and possible hepatotoxic effects related to increased buprenorphine exposure. HCV-infected patients receiving buprenorphine may need lower doses to maintain therapeutic plasma concentrations.

Buprenorphine/Naloxone and methadone effects on laboratory indices of liver health: a randomized trial

BACKGROUND

Buprenorphine/naloxone (BUP) and methadone (MET) are efficacious treatments for opioid dependence, although concerns about a link between BUP and drug-induced hepatitis have been raised. This study compares the effects of BUP and MET on liver health in opioid-dependent participants.

METHODS

This was a randomized controlled trial of 1269 opioid-dependent participants seeking treatment at 8 federally licensed opioid treatment programs and followed for up to 32 weeks between May 2006 and August 2010; 731 participants met "evaluable" criteria defined as completing 24 weeks of medication and providing at least 4 blood samples for transaminase testing. Participants were randomly assigned to receive BUP or MET for 24 weeks. Shift table analysis determined how many evaluable participants moved between categories of low and elevated transaminase levels. Predictors of moving from low to high transaminase levels were identified.

RESULTS

Changes in transaminase levels did not differ by medication condition. Baseline infection with hepatitis C or B was the only significant predictor of moving from low to elevated transaminase levels; 9 BUP and 15 MET participants showed extreme liver test elevations and were more likely than those without extreme elevations to have seroconverted to both hepatitis B and C during the study, or to use illicit drugs during the first 8 weeks of treatment. MET participants were retained longer in treatment than BUP participants.

CONCLUSIONS

This study demonstrated no evidence of liver damage during the initial 6 months of treatment in either condition. Physicians can prescribe either medication without major concern for liver injury.

Analgesics in patients with hepatic impairment: pharmacology and clinical implications

The physiological changes that accompany hepatic impairment alter drug disposition. Porto-systemic shunting might decrease the first-pass metabolism of a drug and lead to increased oral bioavailability of highly extracted drugs. Distribution can also be altered as a result of impaired production of drug-binding proteins or changes in body composition. Furthermore, the activity and capacity of hepatic drug metabolizing enzymes might be affected to various degrees in patients with chronic liver disease. These changes would result in increased concentrations and reduced plasma clearance of drugs, which is often difficult to predict. The pharmacology of analgesics is also altered in liver disease. Pain management in hepatically impaired patients is challenging owing to a lack of evidence-based guidelines for the use of analgesics in this population. Complications such as bleeding due to antiplatelet activity, gastrointestinal irritation, and renal failure are more likely to occur with nonsteroidal anti-inflammatory drugs in patients with severe hepatic impairment. Thus, this analgesic class should be avoided in this population. The pharmacokinetic parameters of paracetamol (acetaminophen) are altered in patients with severe liver disease, but the short-term use of this drug at reduced doses (2 grams daily) appears to be safe in patients with non-alcoholic liver disease. The disposition of a large number of opioid drugs is affected in the presence of hepatic impairment. Certain opioids such as codeine or tramadol, for instance, rely on hepatic biotransformation to active metabolites. A possible reduction of their analgesic effect would be the expected pharmacodynamic consequence of hepatic impairment. Some opioids, such as pethidine (meperidine), have toxic metabolites. The slower elimination of these metabolites can result in an increased risk of toxicity in patients with liver disease, and these drugs should be avoided in this population. The drug clearance of a number of opioids, such as morphine, oxycodone, tramadol and alfentanil, might be decreased in moderate or severe hepatic impairment. For the highly excreted morphine, hydromorphone and oxycodone, an important increase in bioavailability occurs after oral administration in patients with hepatic impairment. Lower doses and/or longer administration intervals should be used when these opioids are administered to patients with liver disease to avoid the risk of accumulation and the potential increase of adverse effects. Finally, the pharmacokinetics of phenylpiperidine opioids such as fentanyl, sufentanil and remifentanil appear to be unaffected in hepatic disease. All opioid drugs can precipitate or aggravate hepatic encephalopathy in patients with severe liver disease, thus requiring cautious use and careful monitoring.

Effect of hepatitis C virus status on liver enzymes in opioid-dependent pregnant women maintained on opioid-agonist medication

AIM

To examine hepatic enzyme test results throughout the course of pregnancy in women maintained on methadone or buprenorphine.

DESIGN

Participants were randomized to either methadone or buprenorphine maintenance. Blood chemistry tests, including liver transaminases and hepatitis C virus (HCV) status, were determined every 4 weeks and once postpartum. As part of a planned secondary analysis, generalized mixed linear models were conducted with aspartate aminotransferase (AST), alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT) as the dependent variables.

SETTING

Six US sites and one European site that provided comprehensive treatment to pregnant opioid-dependent women.

PARTICIPANTS

A total of 175 opioid-dependent pregnant women enrolled in the Maternal Opioid Treatment: Human Experimental Research (MOTHER) study.

FINDINGS

ALT, AST and GGT levels decreased for all subjects across pregnancy trimesters, rising slightly postpartum. HCV-positive subjects exhibited higher transaminases at all time-points compared to HCV-negative subjects, regardless of medication (all Ps < 0.05) condition. Both HCV-positive and negative buprenorphine-maintained participants exhibited lower GGT levels than those who were methadone-maintained (P < 0.05).

CONCLUSIONS

Neither methadone nor buprenorphine appear to have adverse hepatic effects in the treatment of pregnant opioid-dependent women.

Effects of buprenorphine and hepatitis C on liver enzymes in adolescents and young adults

OBJECTIVE

The purpose of this study was to explore changes in transaminase values associated with buprenorphine treatment and hepatitis C status among opioid dependent subjects aged 15-21.

METHODS

152 subjects seeking treatment for opioid dependence were randomized to 2-week detoxification with buprenorphine/naloxone (DETOX) or 12 weeks buprenorphine/naloxone (BUP). Liver chemistries including transaminases were obtained baseline and at 4, 8, and 12 weeks. 111 patients had at least one set of transaminases during treatment and were included in analyses of treatment effects.

RESULTS

Overall, 8/60 BUP participants vs. 12/51 DETOX participants had at least one elevated ALT value during follow-up (Chi-square n.s.). 5/60 BUP participants vs. 11/51 DETOX participants had at least one elevated AST value (Chi-square = 3.194, p = .048). Twenty-eight out of 152 participants were hepatitis C (HCV) positive at baseline, and 4 seroconverted within 12 weeks, 2 in each group. HCV status was significantly associated with transaminase abnormalities (p = .009 and p = .006 for ALT an AST, respectively). HCV status had a strong effect on transaminase abnormalities among participants assigned to DETOX, but not among those assigned to BUP.

CONCLUSIONS

No evidence was found for hepatotoxicity of buprenorphine in this exploratory analysis. HCV was present in a significant minority of participants and was a significant predictor of transaminase elevation. Results suggest that stabilization on buprenorphine may decrease the frequency of transaminase abnormalities associated with HCV in opioid dependent young people. The high rate of seroconversion underscores the importance of effective treatment and prevention.

Short-term safety of buprenorphine/naloxone in HIV-seronegative opioid-dependent Chinese and Thai drug injectors enrolled in HIV Prevention Trials Network 058

BACKGROUND

Buprenorphine/naloxone (BUP/NX) is not licenced for use in China or Thailand and there was little clinical experience with this drug combination in these countries at the inception of HIV Prevention Trial Network (HPTN) 058, a randomized trial comparing risk reduction counselling combined with either short-term or long-term medication assisted treatment with BUP/NX to prevent HIV infection and death amongst opioid-dependent injectors.

METHODS

We conducted a safety phase that included the first 50 subjects enrolled at each of the three initial study sites (N=150). Clinical and laboratory assessments were conducted at baseline and weekly for the first 4 weeks. Changes in laboratory parameters were estimated with random effects models.

RESULTS

BUP/NX was well tolerated by study subjects and opioid withdrawal scores decreased substantially during the 3-day induction. Two participants experienced grade 3 clinical adverse events, which were categorized as probably not related to the study drug. Grade 2 or 3 increases in alanine aminotransferase (ALT) occurred in 25 (17%) subjects. The magnitude of ALT increase over 4-week follow-up was strongly associated with baseline ALT elevation.

CONCLUSIONS

In Chinese and Thai opioid-dependent injectors, we found BUP/NX to be effective in reducing opioid withdrawal symptoms and safe during short-term use. ALT increases were observed over 4-week-follow-up, which are consistent with reports from Western populations. Long-term safety and efficacy evaluations are indicated.

Alcohol and substance use in liver transplant patients

In this article the epidemiology of substance use and substance disorders in the United States and their association with liver disease are reviewed. The relevance of tobacco use and issues of candidacy as it pertains to substance use are discussed. The use of alcohol while on the waitlist and short sobriety are also addressed. The merits of monitoring of patients are discussed, and the outcomes of these patients after liver transplantation are examined. The article concludes with a summary of recommendations for clinicians working with these patients and possible future directions for both clinical care and research.

The autoimmunity of primary biliary cirrhosis and the clonal selection theory

Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease in which an immune-mediated injury targets the small intrahepatic bile ducts. PBC is further characterized by highly specific serum antimitochondrial autoantibodies (AMA) and autoreactive T cells, a striking female predominance, a strong genetic susceptibility, and a plethora of candidate environmental factors to trigger the disease onset. For these reasons PBC appears ideal to represent the developments of the clonal selection theory over the past decades. First, a sufficiently potent autoimmunogenic stimulus in PBC would require the coexistence of numerous pre-existing conditions (mostly genetic, as recently illustrated by genome-wide association studies and animal models) to perpetuate the destruction of the biliary epithelium by the immune system via the persistence of forbidden clones. Second, the proposed modifications of mitochondrial autoantigens caused by infectious agents and/or xenobiotics well illustrate the possibility that peculiar changes in the antigen structure and flexibility may contribute to tolerance breakdown. Third, the unique apoptotic features demonstrated for cholangiocytes are the ideal setting for the development of mitochondrial autoantigen presentation to the immune system through macrophages and AMA thus turning the non traditional mitochondrial antigen into a traditional one. This article will review the current knowledge on PBC etiology and pathogenesis in light of the clonal selection theory developments.