Spontaneous reporting of hepatotoxicity associated with antiandrogens: data from the Spanish pharmacovigilance system

Haemolytic anaemia induced by flutamide: a case report

Flutamide-induced haemolytic anaemia is rare but can be fatal. We describe the case of an 88-year-old man with prostatic carcinoma who, in addition to clinically obvious jaundice, developed haemolytic anaemia after undergoing treatment with flutamide for 5 days. When flutamide was replaced with temporary adrenocortical hormone treatment and blood transfusion, the blood indices and liver function of the patient improved gradually. We emphasise the need for routine monitoring of blood counts for patients undergoing flutamide treatment, and highlight the importance of discontinuing flutamide immediately when haemolytic anaemia occurs.

Potentiation of flutamide-induced hepatotoxicity in mice by Xian-Ling-Gu-Bao through induction of CYP1A2

ETHNOPHARMACOLOGICAL RELEVANCE

Xian-Ling-Gu-Bao (XLGB) Fufang is herbal formula widely used to treat osteoporosis and other bone disorders. Because of its commonality in the clinical use, there is a safety concern over the use of XLGB combined with other androgen deprivation therapy (ADT) drugs such as flutamide (FLU) that is associated with reduced bone density. To date, there have been no evaluations on the side effects of the drug-drug interaction between XLGB and FLU.

AIM OF THE STUDY

The present study was designed to investigate the hepatotoxicity in the context of the combined treatment of XLGB and FLU in a mouse model, and to determine whether the metabolic activation of FLU through induction of CYP1A2 plays a role in the increased hepatoxicity caused by the combination of XLGB and FLU.

MATERIALS AND METHODS

C57 mice were administered with either XLGB (6,160 mg/kg), FLU (300 mg/kg), or with the combination of the two drugs. Animals were treated with XLGB for 5 days before the combined administration of XLGB and FLU for another 4 days. The serum of mice from single or the combined administration groups was collected for biochemical analysis. The mouse liver was collected to examine liver morphological changes, evaluate liver coefficient, as well as determine the mRNA expression of P450 isozymes (Cyp1a2, Cyp3a11 and Cyp2c37). For metabolism analysis, mice were treated with XLGB, FLU, or the combination of XLGB and FLU for 24 h. The urine samples were collected for the analysis of FLU-NAC conjugate by UPLC-Q-Orbitrap MS. The liver microsomes were prepared from fresh livers to determine the activity of metabolizing enzyme CYP1A2.

RESULTS

The combined treatment of XLGB and FLU caused loss of mice body weight and elicited significant liver toxicity as evidenced by an increased liver coefficient and serum lactate dehydrogenase (LDH) activity as well as pathological changes of fatty lesion of liver tissue. FLU increased hepatic expression of Cyp1a2 mRNA that was further elevated in the liver of mice when administered with both FLU and XLGB. Treatment of FLU resulted in an increase in the expression of Cyp3a11 mRNA that was negated when mice were co-treated with FLU and XLGB. No significant difference in Cyp2c37 mRNA expression was observed among the different treatment groups as compared to the control. Analysis of metabolic activity showed that the combined administration caused a synergic effect in elevating the activity of the CYP1A2 enzyme. Mass spectrometry analysis identified the presence of FLU reactive metabolite derived FLU-NAC conjugate in the urine of mice treated with FLU. Strikingly, about a two-fold increase of the FLU-NAC conjugate was detected when treated with both FLU and XLGB, indicating an elevated amount of toxic metabolite produced from FLU in the present of XLGB.

CONCLUSION

FLU and XLGB co-treatment potentiated FLU-induced hepatoxicity. This increased hepatoxicity was mediated through the induction of CYP1A2 activity which in turn enhanced bioactivation of FLU leading to over production of FLU-NAC conjugate and oxidative stress. These results offer warnings about serious side effects of the FLU-XLGB interaction in the clinical practice.

A safety evaluation of current medications for adult women with the polycystic ovarian syndrome not pursuing pregnancy

INTRODUCTION

The polycystic ovary syndrome (PCOS) is a very prevalent disorder in premenopausal women. Cardiovascular risk factors cluster in these patients, raising concern about the safety of the drugs commonly used to ameliorate symptoms of androgen excess in in this population at risk of cardiovascular morbidity.

AREAS COVERED

This review summarizes the clinical efficacy and safety profiles of drugs commonly used for the management of hyperandrogenic symptoms and endometrial protection in adult women with PCOS who do not seek pregnancy.

EXPERT OPINION

Antiandrogenic drugs usually used in adult women with PCOS carry a low risk of severe side effects. In spite of the cardiovascular risk profile of women with PCOS, and that individualized risk assessment is of paramount importance, there is no solid evidence supporting that the use of combined oral contraceptives in these women increases the risk of cardiovascular or thromboembolic events compared with the general population. However, virtually all these drugs are used in an off-label fashion. Large, high-quality studies addressing the long-term safety of pharmacological treatments in women with PCOS are definitely needed.

Flutamide Induces Hepatic Cell Death and Mitochondrial Dysfunction via Inhibition of Nrf2-Mediated Heme Oxygenase-1

Flutamide is a widely used nonsteroidal antiandrogen for prostate cancer therapy, but its clinical application is restricted by the concurrent liver injury. Increasing evidence suggests that flutamide-induced liver injury is associated with oxidative stress, though the precise mechanism is poorly understood. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a master transcription factor regulating endogenous antioxidants including heme oxygenase-1 (HO-1). This study was designed to delineate the role of Nrf2/HO-1 in flutamide-induced hepatic cell injury. Our results showed that flutamide concentration dependently induced cytotoxicity, hydrogen peroxide accumulation, and mitochondrial dysfunction as indicated by mitochondrial membrane potential loss and ATP depletion. The protein expression of Nrf2 and HO-1 was induced by flutamide at 12.5 μM but was downregulated by higher concentrations of flutamide. Silencing either Nrf2 or HO-1 was found to aggravate flutamide-induced hydrogen peroxide accumulation and mitochondrial dysfunction as well as inhibition of the Nrf2 pathway. Moreover, preinduction of HO-1 by Copp significantly attenuated flutamide-induced oxidative stress and mitochondrial dysfunction, while inhibition of HO-1 by Snpp aggravated these deleterious effects. These findings suggest that flutamide-induced hepatic cell death and mitochondrial dysfunction is assoicated with inhibition of Nrf2-mediated HO-1. Pharmacologic intervention of Nrf2/HO-1 may provide a promising therapeutic approach in flutamide-induced liver injury.

The antiandrogen flutamide is a novel aryl hydrocarbon receptor ligand that disrupts bile acid homeostasis in mice through induction of Abcc4

Flutamide (FLU), an oral, nonsteroidal antiandrogen drug used in the treatment of prostate cancer, is associated with idiosyncratic hepatotoxicity that sometimes causes severe liver damage, including cholestasis, jaundice, and liver necrosis. To understand the mechanism of toxicity, a combination of aryl hydrocarbon receptor (Ahr)-deficient (Ahr^-/-) mice, primary hepatocytes, luciferase reporter gene assays, in silico ligand docking and ultra-performance chromatography-quadrupole time-of-flight mass spectrometry-based metabolomics was used. A significant increase of liver weights, and liver and serum bile acid levels was observed after FLU treatment, indicating hepatomegaly and disrupted bile acid homeostasis. Expression of the AhR gene battery was markedly increased in livers of wild-type mice Ahr^+/+ treated with FLU, while no change was noted in Ahr^-/- mice. Messenger RNAs encoded by AhR target genes were induced in primary mouse hepatocytes cultured with FLU, which confirmed the in vivo results. Ligand-docking analysis further predicted that FLU is an AhR agonist ligand which was confirmed by luciferase reporter gene assays. Multivariate data analysis showed that bile acids were responsible for the separation of vehicle- and FLU-treated Ahr^+/+ mice, while there was no separation in Ahr^-/- mice. Expression of mRNA encoding the bile acid transporter ABCC4 was increased and farnesoid X receptor signaling was inhibited in the livers of Ahr^+/+ mice, but not in Ahr^-/- mice treated with FLU, in agreement with the observed downstream metabolic alterations. These findings provide new insights into the mechanism of liver injury caused by FLU treatment involving activation of AhR and the alterations of bile acid homeostasis, which could guide clinical application.

Protective Role of Grape Seed Proanthocyanidins Against Ccl4 Induced Acute Liver Injury in Mice

Background

We investigated the effect of grape seed proanthocyanidins (GSPs) on carbon tetrachloride (CCl₄)-induced acute liver injury.

Material/Methods

Sixty SPF KM mice were randomly divided into 6 groups: the control group, CCl₄-model group, bifendate group (DDB group), and low-, moderate-, and high-dose GSP groups. The following parameters were measured: serum levels of alanine aminotransferase (ALT); aspartate aminotransferase (AST); tumor necrosis factor (TNF)-α; interleukin-6 (IL-6); high-mobility group box (HMGB)-1; body weight; liver, spleen, and thymus indexes; superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity; HMGB1 mRNA; malondialdehyde (MDA) content; hepatocyte proliferation; and changes in liver histology.

Results

Compared to the CCl₄-model group, decreases in liver index and increases in thymus index significantly increased SOD and GSH-Px activities and reduced MDA content, and higher hepatocyte proliferative activity was found in all GSP dose groups and the DDB group (all P<0.001). Compared with the CCl₄-model group, serum TNF-α and IL-6 levels and HMGB 1 mRNA and protein expressions decreased significantly in the high GSP dose group (all P<0.05).

Conclusions

Our results provide strong evidence that administration of GSPs might confer significant protection against CCl₄-induced acute liver injury in mice.

Cyproterone acetate induces a wide spectrum of acute liver damage including corticosteroid-responsive hepatitis: report of 22 cases

BACKGROUND & AIMS

Cyproterone acetate (CPA), an anti-androgenic drug for prostate cancer, has been associated with drug-induced liver injury (DILI). We aim to expand the knowledge on the spectrum of phenotypes and outcomes of CPA-induced DILI.

METHODS

Twenty-two males (70 ± 8 years; range 54-83) developing liver damage as a result of CPA therapy (dose: 150 ± 50 mg/day; range 50-200) were included. Severity index and causality by RUCAM were assessed.

RESULTS

From 1993 to 2013, 22 patients were retrieved. Latency was 163 ± 97 days. Most patients were symptomatic, showing hepatocellular injury (91%) and jaundice. Liver tests at onset were: ALT 18 ± 13 × ULN, ALP 0.7 ± 0.7 × ULN and total serum bilirubin 14 ± 10 mg/dl. International normalized ratio values higher than 1.5 were observed in 14 (66%) patients. Severity was mild in 1 case (4%), moderate in 7 (32%), severe in 11 (50%) and fatal in 3 (14%). Five patients developed ascitis, and four encephalopathy. One patient had a liver injury that resembled autoimmune hepatitis. Eleven (50%) were hospitalized. Nineteen patients recovered after CPA withdrawal, although three required steroid therapy (two of them had high ANA titres). Liver biopsy was performed in seven patients (two hepatocellular collapse, one submassive necrosis, two cholestatic hepatitis, one cirrhosis with iron overload and one autoimmune hepatitis). RUCAM category was 'highly probable' in 19 (86%), 'probable' in 1 (4%), and 'possible' in 2 (9%).

CONCLUSIONS

CPA-induced liver injury is severe and can be fatal, and may occasionally resemble autoimmune DILI. The benefit/risk ratio of this drug should be thoroughly assessed in each patient.

Development of analytical method for simultaneous determination of five rodent unique bile acids in rat plasma using ultra-performance liquid chromatography coupled with time-of-flight mass spectrometry

Bile acids (BAs) are crucial for the diagnosis, follow-up, and prognostics of liver injuries and other BA metabolism related diseases. In particular, rodent unique BAs, α-muricholic acid (α-MCA), β-MCA, ω-MCA, tauro-α-MCA (α-TMCA), and β-TMCA, are valuable biomarkers for preclinical drug development. To the best of our knowledge, however, a simple, selective, sensitive, and robust analytical method for ω-MCA and taurine-conjugated MCAs has never been reported. We have developed a simple, selective, and sensitive analytical method for measurement of 16 BAs including the five rodent unique BAs in rat plasma using an ultra-performance liquid chromatography time-of-flight mass spectrometry (UPLC-TOF-MS) method. Activated charcoal was utilized to prepare BA-free plasma, which served as the surrogate matrix for the preparation of calibration standards and quality control (QC) samples. Results of matrix effects evaluation suggested that the BA-free plasma could be adequate as a surrogate matrix for BAs determination. Three stable isotope labelled internal standards were separated by reverse phase UPLC using gradient elution and were detected by TOF-MS in negative ion mode. The calibration curve was linear for all BAs over a range of 10-25ng/mL to 1000-10,000ng/mL, with overall imprecision below 15% and 20% at lower limit of quantification (LLOQ), respectively. This analytical method was used to determine BA concentrations in more than 300 plasma samples from rats with liver injuries induced using α-naphthylisocyanate, carbon tetrachloride, or flutamide. The alteration of BA concentrations was most evident for necrosis, and cholestasis hepatotoxins, with more subtle effects by steatosis and idiosyncratic hepatotoxins. In conclusion, we have developed a simple, selective, and sensitive analytical method to measure plasma 16 BAs including 5 rodent unique BAs, α-MCA, β-MCA, ω-MCA, α-TMCA, and β-TMCA. Our data suggested that α-TMCA and β-TMCA could be useful for identification or prediction of liver injuries, a currently unmet need in preclinical toxicity. Our method using TOF-MS is useful to determine BAs in rat plasma and of use in structural analyses of metabolites in early stage of drug development.

[Nursing role in reporting adverse drug reactions]

BACKGROUND

The spontaneous report system, in which suspected adverse drug reaction (ADR) are reported by healthcare workers, is currently one of the primary methods to prevent and discover new and serious ADR to marketed medicinal products. The collaboration of nursing professionals with this task makes it possible to improve patient safety and to reduce ADR costs. Although a total of 781 cases of ADR cases were reported in Navarra in 2011, only 7.33% were reported by nurses. The objectives werw to determine the factors that influence nurses in reporting of ADR, and second, to devise strategies which help to increase reporting.

MATERIAL AND METHODS

A bibliographic search for articles that included the words: reacciones adversas medicamentosas (adverse drug reactions), notificación (reporting) and enfermería (nursing) was conducted using the PubMed and Cinhal databases. A total of 107 articles were retrieved, of which 27 were selected according to inclusion and exclusion criteria.

RESULTS

The conclusion learned by reading and analyzing the selected articles was that the factors that affect the notification depend on the attitude of the notifier, as well as personal and professional factors. The main strategies to encourage notification are education and training, motivation, and the availability of facilitating tools.

CONCLUSIONS

The main factors that have an influence on under-notification are the lack of knowledge and motivation among professionals. To solve the problem of under-notification, the main actions and strategies to undertake are education, motivation and persistence.

Subjective and Objective Effects of Androgen Ablation Therapy on Voice

OBJECTIVES

The aim of present study was to evaluate possible side effects of androgen deprivation therapy (ADT) on voice quality by means of objective and subjective measures.

STUDY DESIGN

Cross-sectional.

METHODS

Thirty-five male patients who had been diagnosed with prostate cancer and who had been using bicalutamide and goserelin acetate combination for at least 12 months were included in the study. Thirty healthy nonsmoker males of similar age and without any laryngeal pathology constituted the control group. Acoustic and aerodynamic voice analyses and voice handicap index-10 were applied to both groups. Maximum phonation time, fundamental frequency, jitter, shimmer, and noise-to-harmonic ratio were determined during acoustic and aerodynamic voice analyses.

RESULTS

Maximum phonation times were 18.86 ± 5.24 and 24.20 ± 3.59 in ADT and control groups, respectively. It was significantly higher in the control group. Fundamental frequencies were 143.73 ± 18.47 and 135.00 ± 13.18 in ADT and control groups, respectively. Jitter values were 2.72 ± 0.62 and 1.99 ± 0.27 in ADT and control groups, respectively. Shimmer values were 11.50 ± 1.81 and 10.48 ± 1.36 in ADT and control groups, respectively. Fundamental frequency, jitter, and shimmer values were significantly higher in the ADT group. Noise-to-harmonic ratio values did not differ between groups. Voice handicap index-10 result was significantly higher in the ADT group.

CONCLUSIONS

ADT has adverse effects on the human voice. Prospective studies with long-term follow-up of a larger cohort are required for more detailed analysis.

Bicalutamide-induced hepatotoxicity: A rare adverse effect

Patient: Male, 81

Final Diagnosis: Prostate cancer

Symptoms: Anorexia • dark urine • joundice • letargy

Medication: Casodex

Clinical Procedure: —

Specialty: Oncology

Androgen receptor roles in hepatocellular carcinoma, fatty liver, cirrhosis and hepatitis

Androgen/androgen receptor (AR) signaling plays important roles in normal liver function and in progression of liver diseases. In studies of noncancerous liver diseases, AR knockout mouse models of liver disease have revealed that androgen/AR signaling suppresses the development of steatosis, virus-related hepatitis, and cirrhosis. In addition, studies have shown that targeting AR in bone marrow-derived mesenchymal stem cells (BM-MSCs) improves their self-renewal and migration potentials, thereby increasing the efficacy of BM-MSC transplantation as a way to control the progression of cirrhosis. Androgen/AR signaling is known to be involved in the initiation of carcinogen- or hepatitis B virus-related hepatocellular carcinoma (HCC). However, studies have demonstrated that AR, rather than androgen, plays the dominant role in cancer initiation. Therefore, targeting AR might be an appropriate therapy for patients with early-stage HCC. In contrast, androgen/AR signaling has been shown to suppress metastasis of HCC in patients with late-stage disease. In addition, there is evidence that therapy comprising Sorafenib and agents that enhance the functional expression of AR may suppress the progression of late-stage HCC.

Epidemiology, diagnosis and management of hirsutism: a consensus statement by the Androgen Excess and Polycystic Ovary Syndrome Society

BACKGROUND

Hirsutism, defined by the presence of excessive terminal hair in androgen-sensitive areas of the female body, is one of the most common disorders in women during reproductive age.

METHODS

We conducted a systematic review and critical assessment of the available evidence pertaining to the epidemiology, pathophysiology, diagnosis and management of hirsutism.

RESULTS

The prevalence of hirsutism is ~10% in most populations, with the important exception of Far-East Asian women who present hirsutism less frequently. Although usually caused by relatively benign functional conditions, with the polycystic ovary syndrome leading the list of the most frequent etiologies, hirsutism may be the presenting symptom of a life-threatening tumor requiring immediate intervention.

CONCLUSIONS

Following evidence-based diagnostic and treatment strategies that address not only the amelioration of hirsutism but also the treatment of the underlying etiology is essential for the proper management of affected women, especially considering that hirsutism is, in most cases, a chronic disorder needing long-term follow-up. Accordingly, we provide evidence-based guidelines for the etiological diagnosis and for the management of this frequent medical complaint.

Fatal fulminant hepatitis in a chimpanzee (Pan troglodytes) receiving cyproterone acetate

Cyproterone acetate is a steroidal anti-androgen that has been used in human medicine for contraceptive purposes as well as treatment of medical conditions responsive to suppression of testosterone production. While serious side effects are considered to be rare, sporadic cases of severe hepatitis have been reported, including several fatal cases. This report describes a case of fatal fulminant hepatitis in one of four male chimpanzees (Pan troglodytes) that were undergoing trial treatment with cyproterone acetate to decrease inter-male aggression.

An overview of coagulation disorders in cancer patients

A diversity of coagulation disorders in cancer patients arise from tumor-specific growth characteristics, neoangiogenesis with impaired endothelial lining, defective myelopoiesis, hypoproteinemia or metastatic lesions growth with organ dysfunction. Recent investigations have found a clinically relevant correlation of coagulation disorders and tumor growth. These prompted new therapeutic strategies focused on growth factors with the aim to control tumor metastasis, particularly if used for the treatment of micrometastatic disease. However, such treatment may lead to the life threatening coagulation imbalance. A coagulation homeostasis may become further impaired after nonsurgical cancer therapy, especially after preoperative irradiation, which produces lesions precipitating both bleeding and thrombosis. Anticancer chemotherapy may affect liver function and decrease the synthesis of both procoagulation and anticoagulation factors. The most of chemotherapeutic protocols affect platelet synthesis, which arises as a principal dose-limiting side effect. It was observed both during combined systemic chemotherapy and local antitumor therapy. Although the side effects produced by chemotherapy are reversible, endothelial lesions may persist for many years after the anticancer treatment. Instead of cancer patients, there's a growing cohort of patients with nonmalignant diseases who use cytostatics in the perioperative period, and are candidates for surgical procedures not related to their malignant disease, i.e. hernia repair. In this patient population a special attention must be paid to the preoperative evaluation of coagulation status and thromboprophylaxis. This overview reminds the most common coagulation disorders in cancer patients in the perioperative period. It emphasizes the need for proper patient monitoring which may facilitate the diagnostics and treatment of cancer-related coagulation disorders in the perioperative setting.

Transport, Metabolism, and Hepatotoxicity of Flutamide, Drug–Drug Interaction with Acetaminophen Involving Phase I and Phase II Metabolites

Treatment with flutamide has been associated with clinical hepatotoxicty. The toxicity, metabolism,and transport of flutamide were investigated using cultured human hepatocytes. Flutamide and its major metabolite, 2-hydroxyflutamide, caused an inhibition of taurocholate efflux in human hepatocytes with an IC50=75 microM and 110 microM, respectively. Treatment of hepatocytes with flutamide or 2-hydroxyflutamide for 24 h resulted in time- and concentration-dependent toxicity as assessed by inhibition of protein synthesis. Toxicity was greater after 1 h than after 24 h of treatment. Recovery in inhibition of protein synthesis by 24 h was attributed to the decreased presence of flutamide due to its metabolism. Flutamide was metabolized by hepatocytes to several metabolites, and formation of reactive intermediates of flutamide, as evidenced by the presence of glutathione-related adducts, was observed. Inhibition of flutamide metabolism by 1-aminobenzotriazole (ABT) resulted in enhancement of flutamide toxicity, which was associated with sustained levels of nonmetabolized drug. ABT also prevented the formation of reactive intermediates of flutamide. There was an additive toxicity when cells were treated with a combination of flutamide and 2-hydroxyflutamide. Simultaneous treatment with flutamide and acetaminophen (APAP) resulted in additive to synergistic toxic effects. Flutamide and APAP were found to have significant effects on each other's metabolism. Flutamide inhibited glucuronidation and sulfation of APAP, resulting in greater amounts of APAP available for bioactivation. APAP inhibited the hydroxylation of flutamide, and subsequent sulfation and acetylation of 4-nitro-3-(trifluoromethyl) aniline, a metabolite of flutamide. In summary, we suggest that inhibition of bile acid efflux by flutamide and its 2-hydroxy metabolite may play a role in flutamide-induced liver injury. Both flutamide and 2-hydroxyflutamide are responsible for cytotoxicity if not metabolized. The data also suggest a possible drug-drug interaction between flutamide and APAP, resulting in inhibition of flutamide metabolism and increased APAP bioactivation and toxicity.

Comparison of the cytotoxicity of the nitroaromatic drug flutamide to its cyano analogue in the hepatocyte cell line TAMH: evidence for complex I inhibition and mitochondrial dysfunction using toxicogenomic screening

Flutamide (FLU) is an antiandrogen primarily used in the treatment of metastatic prostate cancer. It is an idiosyncratic hepatotoxicant that sometimes results in severe liver toxicity. FLU possesses a nitroaromatic group, which may be a contributor to its mechanism of toxicity. A nitro to cyano analogue of FLU (CYA) was synthesized and used to test this hypothesis in the TGFalpha-transfected mouse hepatocyte cell line (TAMH). MTT cell viability assays and confocal microscopy showed that hepatocytes are more sensitive to cytotoxicity caused by FLU than CYA (LD 50 75 vs 150 microM, respectively). Despite the structural modification, the antiandrogen activity of CYA is comparable to that of FLU. Comparisons of transcriptomic changes caused by FLU with those caused by a panel of known cytotoxicants [acetaminophen, tetrafluoroethylcysteine, diquat, and rotenone (ROT)] indicated that FLU results in a temporal gene expression pattern similar to ROT, a known inhibitor of complex I of the electron transport chain. A subsequent microarray analysis comparing FLU to CYA and ROT revealed many similarities among these three compounds; however, FLU and ROT result in more substantial changes than CYA in the expression of genes associated with oxidative phosphorylation, fatty acid beta-oxidation, antioxidant defense, and cell death pathways. Electron microscopy confirmed that FLU leads to mitochondrial toxicity that has some similarities to the mitochondrial effects of ROT, but the morphologic changes caused by FLU were greater in scope with both intra- and intercellular manifestations. Biochemical studies confirmed that both ROT and FLU deplete cellular ATP levels and inhibit complex I of the electron transport chain to a greater extent than CYA. Thus, as compared to CYA, the nitroaromatic group of FLU enhances cytotoxicity to hepatocytes, likely through mechanisms involving mitochondrial dysfunction and ATP depletion that include complex I inhibition.

Cancer chemotherapy I: hepatocellular injury

Although hepatotoxicity is a frequent concern with all medications, chemotherapeutic agents are more often implicated in causing liver damage than most other drug classes. In many instances, these reactions are considered dose related because cytotoxic therapy directed at rapidly growing cancer cells may readily impact hepatocytes even though they are dividing more slowly. Because the stakes (remission of cancer) are high, so are the risks that the oncologist and the patient are willing to assume. The dose of many chemotherapeutic agents is limited by the toxic effects on the lungs, bone marrow, kidneys, and gastrointestinal system, including the liver. An awareness of the toxic potential of each chemotherapeutic agent is necessary before initiation of new oncologic treatments.