Tianeptine--an instance of drug-induced hepatotoxicity predicted by prospective experimental studies

Seven-membered N-heterocycles as approved drugs and promising leads in medicinal chemistry as well as the metal-free domino access to their scaffolds

Azepanes or azepines are structural motifs of many drugs, drug candidates and evaluated lead compounds. Even though compounds having N-heterocyclic 7-membered rings are often found in nature (e.g. alkaloids), the natural compounds of this group are rather rare as approved therapeutics. Thus, recently studied and approved azepane or azepine-congeners predominantly consist of semi-synthetically or synthetically-obtained scaffolds. In this review a comparison of approved drugs and recently investigated leads was proposed taking into regard their structural aspects (stereochemistry), biological activities, pharmacokinetic properties and confirmed molecular targets. The 7-membered N-heterocycles reveal a wide range of biological activities, not only against CNS diseases, but also as e.g. antibacterial, anticancer, antiviral, antiparasitic and against allergy agents. As most of the approved or investigated potential drugs or lead structures, belonging to 7-membered N-heterocycles, are synthetic scaffolds, this report also reveals different and efficient metal-free cascade approaches useful to synthesize both simple azepane or azepine-containing congeners and those of oligocyclic structures. Stereochemistry of azepane/azepine fused systems, in view of biological data and binding with the targets, is discussed. Apart from the approved drugs, we compare advances in SAR studies of 7-membered N-heterocycles (mainly from 2018 to 2023), whereas the related synthetic part concerning various domino strategies is focused on the last ten years.

Tricyclic antidepressants induce liver inflammation by targeting NLRP3 inflammasome activation

BACKGROUND

Idiosyncratic drug-induced liver injury (IDILI) is common in hepatology practices and, in some cases, lethal. Increasing evidence show that tricyclic antidepressants (TCAs) can induce IDILI in clinical applications but the underlying mechanisms are still poorly understood.

METHODS

We assessed the specificity of several TCAs for NLRP3 inflammasome via MCC950 (a selective NLRP3 inhibitor) pretreatment and Nlrp3 knockout (Nlrp3^-/-) BMDMs. Meanwhile, the role of NLRP3 inflammasome in the TCA nortriptyline-induced hepatotoxicity was demonstrated in Nlrp3^-/- mice.

RESULTS

We reported here that nortriptyline, a common TCA, induced idiosyncratic hepatotoxicity in a NLRP3 inflammasome-dependent manner in mildly inflammatory states. In parallel in vitro studies, nortriptyline triggered the inflammasome activation, which was completely blocked by Nlrp3 deficiency or MCC950 pretreatment. Furthermore, nortriptyline treatment led to mitochondrial damage and subsequent mitochondrial reactive oxygen species (mtROS) production resulting in aberrant activation of the NLRP3 inflammasome; a selective mitochondrial ROS inhibitor pretreatment dramatically abrogated nortriptyline-triggered the NLRP3 inflammasome activation. Notably, exposure to other TCAs also induced aberrant activation of the NLRP3 inflammasome by triggering upstream signaling events.

CONCLUSION

Collectively, our findings revealed that the NLRP3 inflammasome may act as a crucial target for TCA agents and suggested that the core structures of TCAs may contribute to the aberrant activation of NLRP3 inflammasome induced by them, an important factor involved in the pathogenesis of TCA-induced liver injury. Video Abstract.

Phosphatidylcholine (18:0/20:4), a potential biomarker to predict ethionamide-induced hepatic steatosis in rats

Ethionamide (ETH), a second-line drug for multi-drug resistant tuberculosis, is known to cause hepatic steatosis in rats and humans. To investigate predictive biomarkers for ETH-induced steatosis, we performed lipidomics analysis using plasma and liver samples collected from rats treated orally with ETH at 30 and 100 mg/kg for 14 days. The ETH-treated rats developed hepatic steatosis with Oil Red O staining-positive vacuolation in the centrilobular hepatocytes accompanied by increased hepatic contents of triglycerides (TG) and decreased plasma TG and total cholesterol levels. A multivariate analysis for lipid profiles revealed differences in each of the 35 lipid species in the plasma and liver between the control and the ETH-treated rats. Of those lipids, phosphatidylcholine (PC) (18:0/20:4) decreased dose-dependently in both the plasma and liver. Moreover, serum TG-rich very low-density lipoprotein (VLDL) levels, especially the large particle fraction of VLDL composed of PC containing arachidonic acid (20:4) involved in hepatic secretion of TG, were decreased dose-dependently. In conclusion, the decreased PC (18:0/20:4) in the liver, possibly leading to suppression of hepatic TG secretion, was considered to be involved in the pathogenesis of the ETH-induced hepatic steatosis. Therefore, plasma PC (18:0/20:4) levels are proposed as mechanism-related biomarkers for ETH-induced hepatic steatosis.

Antidepressants- and antipsychotics-induced hepatotoxicity

Drug-induced liver injury (DILI) is a serious health burden. It has diverse clinical presentations that can escalate to acute liver failure. The worldwide increase in the use of psychotropic drugs, their long-term use on a daily basis, common comorbidities of psychiatric and metabolic disorders, and polypharmacy in psychiatric patients increase the incidence of psychotropics-induced DILI. During the last 2 decades, hepatotoxicity of various antidepressants (ADs) and antipsychotics (APs) received much attention. Comprehensive review and discussion of accumulated literature data concerning this issue are performed in this study, as hepatotoxic effects of most commonly prescribed ADs and APs are classified, described, and discussed. The review focuses on ADs and APs characterized by the risk of causing liver damage and highlights the ones found to cause life-threatening or severe DILI cases. In parallel, an overview of hepatic oxidative stress, inflammation, and steatosis underlying DILI is provided, followed by extensive review and discussion of the pathophysiology of AD- and AP-induced DILI revealed in case reports, and animal and in vitro studies. The consequences of some ADs and APs ability to affect drug-metabolizing enzymes and therefore provoke drug–drug interactions are also addressed. Continuous collecting of data on drugs, mechanisms, and risk factors for DILI, as well as critical data reviewing, is crucial for easier DILI diagnosis and more efficient risk assessment of AD- and AP-induced DILI. Higher awareness of ADs and APs hepatotoxicity is the prerequisite for their safe use and optimal dosing.

Antidepressants and Hepatotoxicity: A Cohort Study among 5 Million Individuals Registered in the French National Health Insurance Database

BACKGROUND

Hepatotoxicity may be a concern when prescribing antidepressants. Nevertheless, this risk remains poorly understood for serotonin and noradrenaline reuptake inhibitors (SNRIs: venlafaxine, milnacipran, duloxetine) and 'other antidepressants' (mianserin, mirtazapine, tianeptine and agomelatine), particularly in comparison with selective serotonin reuptake inhibitors (SSRIs: fluoxetine, citalopram, paroxetine, sertraline, fluvoxamine, escitalopram), which are by far the most commonly prescribed antidepressants.

OBJECTIVE

We quantified the risk of serious liver injury associated with new use of SNRIs and 'other antidepressants' compared with SSRIs in real-life practice.

METHODS

Based on the French national health insurance database, this cohort study included 4,966,825 individuals aged 25 years and older with a first reimbursement of SSRIs, SNRIs or 'other antidepressants' between January 2010 and June 2015. We compared the risk of serious liver injury within the 6 months following antidepressant initiation according to antidepressant class, with SSRIs as the reference, using an inverse probability-of-treatment-weighted Cox proportional hazard model adjusted for demographic characteristics and risk factors of liver injury.

RESULTS

We identified 382 serious liver injuries overall (none for milnacipran initiators). Age and gender standardized incidence rates per 100,000 person-years were 19.2 for SSRIs, 22.2 for venlafaxine, 12.6 for duloxetine, 21.5 for mianserin, 32.8 for mirtazapine, 31.6 for tianeptine and 24.6 for agomelatine initiators. Initiation of antidepressants of interest versus SSRIs was not associated with an increased risk of serious liver injury [adjusted hazard ratios (95% confidence interval): venlafaxine 1.17 (0.83-1.64), duloxetine 0.54 (0.28-1.02), mianserin 0.90 (0.58-1.41), mirtazapine 1.17 (0.67-2.02), tianeptine 1.35 (0.82-2.23) and agomelatine 1.07 (0.51-2.23)]. This finding was confirmed by the results of an additional study using a case-time-control design.

CONCLUSION

These results do not provide evidence of an increased risk of serious liver injury following initiation of SNRIs or 'other antidepressants' compared with SSRIs in real-life practice. This could reflect an inherent lack of difference in risk between the drug classes, or the fact that individuals with higher susceptibility to drug-induced liver injury are not prescribed drugs considered to be more hepatotoxic.

Tianeptine combination for partial or non-response to selective serotonin re-uptake inhibitor monotherapy

AIMS

The goal of this study was to assess the efficacy and tolerability of tianeptine in combination with selective serotonin re-uptake inhibitor (SSRI) in partial responders or non-responders to SSRI monotherapy.

METHODS

In this prospective, open-label, 6-week study, 150 patients with major depressive disorder who had previously not responded or partially responded to SSRI monotherapy were recruited. Tianeptine was given in combination with an SSRI for 6 weeks.

RESULTS

Significant improvements were observed in the mean scores of the Hamilton Depression Rating Scale (HDRS), Montgomery-Åsberg Depression Rating Scale (MADRS), and Clinical Global Impression-Severity (CGI-S). The change in the mean HDRS, MADRS, and CGI-S scores was significant from week 1. The response rates were 64.7% (HDRS) and 68.7% (MADRS), and the remission rates were 34.0% (HDRS) and 42.0% (MADRS) at week 6. Thirty-six patients (24.0%) reported adverse events that were determined by the investigator to be related to one of the study drugs. The tianeptine and SSRI combination was generally well-tolerated.

CONCLUSIONS

A combination strategy with tianeptine may be an effective and well-tolerated tool for patients who have failed to adequately respond to SSRI monotherapy.

Which psychotropic medications induce hepatotoxicity?

OBJECTIVE

Safe prescribing practices to minimize pharmaceutically induced liver damage or worsening of preexisting conditions require knowledge about medicines with hepatotoxic potential. This paper reviews psychotropic medications and their effects on the liver.

METHODS

A MEDLINE search was performed utilizing the phrase "drug-induced liver injury" with various categories of psychiatric drugs. Only articles written in English were utilized.

RESULTS

Hepatotoxicity can be acute or chronic in nature. Medication discontinuation is necessary in acute forms, while close monitoring is required in milder forms of medication-induced chronic liver damage. Nefazodone, pemoline and/or tacrine are the highest offenders. Carbamazepine and valproate products (e.g., divalproex) can lead to this adverse event and should be avoided in patients with liver disease, persons with alcohol misuse or those consuming high doses of acetaminophen.

CONCLUSION

Knowing the risk levels associated with various medicines is important; prescribing multiple drugs with hepatotoxic effects should be avoided. One should educate patients about early warning signs of liver injury. Always provide clinical and laboratory monitoring before and during the use of hepatotoxic drugs. Clinical features and laboratory results govern medication prescribing with ongoing risk-to-benefit ratio assessment during pharmacotherapy.

Drug-induced toxicity on mitochondria and lipid metabolism: mechanistic diversity and deleterious consequences for the liver

Numerous investigations have shown that mitochondrial dysfunction is a major mechanism of drug-induced liver injury, which involves the parent drug or a reactive metabolite generated through cytochromes P450. Depending of their nature and their severity, the mitochondrial alterations are able to induce mild to fulminant hepatic cytolysis and steatosis (lipid accumulation), which can have different clinical and pathological features. Microvesicular steatosis, a potentially severe liver lesion usually associated with liver failure and profound hypoglycemia, is due to a major inhibition of mitochondrial fatty acid oxidation (FAO). Macrovacuolar steatosis, a relatively benign liver lesion in the short term, can be induced not only by a moderate reduction of mitochondrial FAO but also by an increased hepatic de novo lipid synthesis and a decreased secretion of VLDL-associated triglycerides. Moreover, recent investigations suggest that some drugs could favor lipid deposition in the liver through primary alterations of white adipose tissue (WAT) homeostasis. If the treatment is not interrupted, steatosis can evolve toward steatohepatitis, which is characterized not only by lipid accumulation but also by necroinflammation and fibrosis. Although the mechanisms involved in this aggravation are not fully characterized, it appears that overproduction of reactive oxygen species by the damaged mitochondria could play a salient role. Numerous factors could favor drug-induced mitochondrial and metabolic toxicity, such as the structure of the parent molecule, genetic predispositions (in particular those involving mitochondrial enzymes), alcohol intoxication, hepatitis virus C infection, and obesity. In obese and diabetic patients, some drugs may induce acute liver injury more frequently while others may worsen the pre-existent steatosis (or steatohepatitis).

Symptomatic hyperlactataemia precipitated by the addition of tetracycline to combination antiretroviral therapy

Hyperlactataemia in the setting of combination antiretroviral therapy for HIV infection occurs on a spectrum ranging from common, asymptomatic laboratory abnormalities to rare, potentially life-threatening lactic acidosis. Some other medications, including the biguanides, tetracycline, and even linezolid, have rarely been reported to cause lactic acidosis. Recently, cases of lactic acidosis or hyperlactataemia have been reported in patients receiving combination antiretroviral therapy that have been precipitated by the addition of other medications-eg, metformin or ribavirin. We report a case of symptomatic hyperlactataemia in a patient on combination antiretroviral therapy that was likely precipitated by the addition of tetracycline and discuss the broader implications of other medications with the potential to cause hyperlactataemia in the setting of combination antiretroviral therapy.

Bile duct disorders

Drug-induced bile duct injury related prolonged or chronic cholestasis is recognized as a common side effect of treatment with several drugs. The severity and duration of the clinical symptoms suggest that this increase in number of reports is not only related to clinician and pathologists being increasingly aware of the condition, but also may represent a true increase in incidence likely related to a time-related growing experience with newer drugs. This clinical presentation encompasses a wide variety of features that may be the source of diagnostic difficulties, especially in the cases where cholestasis occurs days or weeks after the completion of therapy. Even more puzzling is the initial picture of hepatocholangitis, which may be silent and ensuing bile duct paucity with chronic anicteric cholestasis may be another source of diagnostic difficulties in the long-term. These diagnostic difficulties suggest that some of the cases of the so-called "idiopathic adulthood ductopenia" may originate from overlooked drug induced vanishing bile duct syndrome. The pathogenesis of the syndrome remains largely unknown and the determinants of prognosis and outcome. From reproducible data obtained in different studies investigating HLA-dependent predisposition, one may assume that genetics plays a major role even if other unknown additive factors are also likely involved. Severity of initial hepatocholangitis is likely to represent another important determinant of severity and prognosis, however to be assessed in larger longitudinal studies. Therapy of large bile duct injury mimics that of primary sclerosing cholangitis. Treatment of small bile duct injury remains disappointing. Corticosteroids are invariably ineffective. Ursodeoxycholic acid as been shown to induce improvement of clinical and biochemical cholestasis in some selected cases, its efficacy being however unpredictable. Preliminary data about the natural history of the vanishing bile duct syndrome suggest that therapy might be more effective when initiated early.

Tianeptine: a review of its use in depressive disorders

Tianeptine is an antidepressant agent with a novel neurochemical profile. It increases serotonin (5-hydroxytryptamine; 5-HT) uptake in the brain (in contrast with most antidepressant agents) and reduces stress-induced atrophy of neuronal dendrites. Like the selective serotonin reuptake inhibitors (SSRIs) and in contrast with most tricyclic antidepressant agents, tianeptine does not appear to be associated with adverse cognitive, psychomotor, sleep, cardiovascular or bodyweight effects and has a low propensity for abuse. Tianeptine has a comparatively favourable pharmacokinetic profile. It is not subject to first-pass hepatic metabolism, has high bioavailability and limited distribution, and is rapidly eliminated. While this offers advantages for tianeptine over the tricyclic antidepressant agents in terms of dose titration, treatment changes and potential drug interactions, its rapid elimination makes adherence to dosage schedules more important. Tianeptine differs from most antidepressants in that it is not primarily metabolised by the hepatic cytochrome P450 system, indicating less likelihood of drug-drug interactions; this is of particular interest for elderly patients. Tianeptine, in dosages of 25 to 50 mg/day, has been investigated in patients with major depression, depressed bipolar disorder, dysthymia or adjustment disorder. It has equivalent antidepressant efficacy to several classical antidepressant agents (amitriptyline, clomipramine, imipramine, mianserin) and the SSRIs fluoxetine (in most patients), paroxetine and sertraline. Comparison with maprotiline indicated superior efficacy for tianeptine but dothiepin appeared superior in another study. Extended treatment with tianeptine decreases the incidence of relapse/recurrence of depression. Tianeptine appears to be as effective as fluoxetine, sertraline, amitriptyline, clomipramine and mianserin and more effective than maprotiline in improving associated anxiety in patients with depressive disorders. Depression and anxiety symptoms in alcohol dependant patients also respond well to tianeptine. The adverse effects associated with tianeptine are similar in many respects to those of the SSRIs and minimal in comparison with the tricyclic antidepressants. The most common adverse effects are nausea, constipation, abdominal pain, headache, dizziness and changes in dreaming. Anticholinergic effects occur less often with tianeptine than with tricyclic agents. Hepatoxicity is rare. The dosage should be decreased in elderly patients and those with severe renal failure, but adjustment is not necessary in patients with alcoholism or hepatic impairment, or those undergoing haemodialysis.

CONCLUSIONS

The antidepressant efficacy and favourable tolerability and pharmacokinetic profiles of tianeptine in patients with depression, including those with associated anxiety, have been proven; the data indicate that it may have additional potential in specific subgroups of depressed patients such as the elderly and those with chronic alcoholism.

Drug-induced liver diseases

Drug-induced liver injuries make up a persisting and challenging problem for physicians, health agencies and pharmaceutical firms. The clinical expression is polymorphous, acute hepatitis being predominant. The diagnosis is frequently difficult because of the absence of specific signs in most cases and mainly relies on the exclusion of other causes. The diagnosis should be particularly evoked in patients over 50 yr who are taking many drugs, after viral infections have been ruled out. Acute hepatocellular hepatitis is particularly severe because of the risk of fulminant hepatitis or of a more insidious course leading to cirrhosis. Cross hepatotoxicity can sometimes occur. One should avoid re-administration of not only the causative agents but also of other drugs belonging to the same family or having a related chemical structure. The prediction of the hepatotoxicity of new drugs must be improved. Investigations would be particularly useful for drugs having critical chemical structures and belonging to families with an established history of hepatotoxicity.

Inhibition of mitochondrial beta-oxidation as a mechanism of hepatotoxicity

Severe and prolonged impairment of mitochondrial beta-oxidation leads to microvesicular steatosis, and, in severe forms, to liver failure, coma and death. Impairment of mitochondrial beta-oxidation may be either genetic or acquired, and different causes may add their effects to inhibit beta-oxidation severely and trigger the syndrome. Drugs and some endogenous compounds can sequester coenzyme A and/or inhibit mitochondrial beta-oxidation enzymes (aspirin, valproic acid, tetracyclines, several 2-arylpropionate anti-inflammatory drugs, amineptine and tianeptine); they may inhibit both mitochondrial beta-oxidation and oxidative phosphorylation (endogenous bile acids, amiodarone, perhexiline and diethylaminoethoxyhexestrol), or they may impair mitochondrial DNA transcription (interferon-alpha), or decrease mitochondrial DNA replication (dideoxynucleoside analogues), while other compounds (ethanol, female sex hormones) act through a combination of different mechanisms. Any investigational molecule should be screened for such effects.