Liver function test abnormalities and pruritus in a patient treated with atorvastatin: case report and review of the literature

The 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (also known as statins) are associated with elevated transaminase levels in 1-3% of patients. Therapy with these drugs requires monitoring of alanine aminotransferase (ALT) levels because animal studies and premarketing clinical trials showed signs of hepatotoxicity that were primarily minor elevations of ALT. Nevertheless, postmarketing experience suggests that hepatotoxicity is rare, and that elevated ALT levels are reversible with continued therapy and probably are related to cholesterol lowering. Based on the low occurrence of ALT elevations and the lack of clinical evidence of hepatotoxicity, some clinicians are calling for a change in the current practice of monitoring liver function tests. We report, however, the case of a 71-year-old woman who was receiving atorvastatin and experienced elevated transaminase levels on two occasions, and developed pruritus on rechallenge with the drug. Thus, clinicians should be aware of asymptomatic elevations in liver function tests in patients receiving atorvastatin who do not have known risk factors for liver damage.     

Adverse reactions of HMG—CoA reductase inhibitors as a consequence of drug—drug interaction

Use of HMG-CoA reductase inhibitors in treating hypercholesterolemia is a well-established therapy.Presently,atorvastatin,fluvastatin,lovastatin,simvastatin and pravastatin are used clinically.Cerivastatin was pulled from the market in 2001 due to its higher risk of inducing rhabdomyolysis than all other drugs.Hepatotoxicity and rhabdomyolysis are the known adverse reactions by these drugs.However,the hepatotoxicity has been regarded to be mild,and is now referred to as transaminitis.Rhadomyolysis occurs in rare instances but is sometimes life threatening as a result of renal failure caused by myoglobinemia.The mechanism leading to rhabdomyolysis is unknown but in many of the reported cases,increased plasma concentratinos of thes drugs have been observed,most likely as a consequence of drug interaction.Inhibition of CYP 3A4 and UGT is believed to be the reason for this interaction.     

Investigation of combined CYP3A4 inductive/inhibitory properties by studying statin interactions: a model study with the renin inhibitor ACT-178882

Purpose

ACT-178882, a direct renin inhibitor, was used as a model compound in an elaborate drug–drug interaction study with atorvastatin and simvastatin to explore complex CYP3A4 inductive and inhibitory properties.

Methods

Thirty-two healthy male subjects received single doses of 20 mg atorvastatin and 20 mg simvastatin on days 1, 9, 31, and 41. On days 6 to 33, 500 mg ACT-178882 was administered once daily. Plasma concentrations of ACT-178882, simvastatin, and atorvastatin were measured by LC-MS/MS. Routine safety assessments were performed throughout the study.

Results

Exposure (as based on area under the curve) to simvastatin and 6β-hydroxyacid simvastatin increased (90 % confidence interval) 4.63-fold (3.90, 5.50) and 3.71-fold (3.19, 4.32), respectively, when comparing day 9 and day 1. On day 9, exposure to atorvastatin was similar but C_max decreased, while both variables decreased for ortho-hydroxy atorvastatin when compared to day 1. On day 31, after prolonged administration of ACT-178882, exposure to atorvastatin, ortho-hydroxy atorvastatin, simvastatin, and 6β-hydroxyacid simvastatin decreased by 14, 19, 21, and 27 %, respectively, when compared to day 9. However, on this day, exposure to simvastatin and its metabolite was still markedly higher when compared to day 1. Effects of ACT-178882 had largely dissipated on day 41.

Conclusions

This design enabled the study of complex time-dependent effects on CYP3A4 activity with clinically relevant substrates.     

阿托伐他汀的基因多态性研究进展

阿托伐他汀是临床上广泛使用的调血脂药物,长期使用能够预防并减少动脉粥样硬化性心血管疾病（ASCVD）的发生,但阿托伐他汀的疗效具有显著的个体间差异,有些个体不能达到预期调脂目标值或出现严重的不良反应。这与个体间的遗传多样性有关,遗传变异可导致药物体内处置不同,从而导致临床疗效和不良反应有差异。对影响阿托伐他汀药物反应的药物代谢酶、药物转运体、药物作用靶点及与脂质代谢相关基因多态性加以综述,并从基因水平上探讨不同个体使用阿托伐他汀的药动学、药效学及不良反应易感性差别的原因。     

Risk-benefit of HMG-CoA reductase inhibitors in the treatment of HIV protease inhibitor-related hyperlipidaemia

HIV protease inhibitors decrease mortality and improve quality of life in patients with HIV infection. However, these drugs have been associated with serum lipid elevations, which may pose an increased risk of cardiovascular disease and pancreatitis. Treatment of protease inhibitor-related hyperlipidaemia (PIH) is complicated by drug interactions, which significantly increase concentrations of most 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins). Although pravastatin and atorvastatin effectively lower cholesterol and triglyceride concentrations in HIV-infected patients, a significant number of patients did not achieve their National Cholesterol Education Program low density lipoprotein concentration goals. Nonetheless, due to the increased risk of rhabdomyolysis with elevated statin concentrations, atorvastatin should be considered a second-line agent. The limited available PIH data supports the fact that pravastatin and atorvastatin are well-tolerated in HIV-infected individuals. More data are needed on the appropriate starting doses, maximum safe doses, role of combination statin-fibrate therapy, documentation of coronary heart disease benefit and incidence of myotoxicity and hepatotoxicity. Pravastatin has an acceptable risk-benefit ratio in PIH, while theoretical toxicity concerns exist with atorvastatin.     

Hepatotoxicity upon using niacin to pass a drug test: A case report

Objectives

To report a case of hepatotoxicity when niacin was used by a patient with HIV to pass a drug test.

Risk-benefit of HMG-CoA reductase inhibitors in the treatment of HIV protease inhibitor-related hyperlipidaemia

HIV protease inhibitors decrease mortality and improve quality of life in patients with HIV infection. However, these drugs have been associated with serum lipid elevations, which may pose an increased risk of cardiovascular disease and pancreatitis. Treatment of protease inhibitor-related hyperlipidaemia (PIH) is complicated by drug interactions, which significantly increase concentrations of most 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors (statins). Although pravastatin and atorvastatin effectively lower cholesterol and triglyceride concentrations in HIV-infected patients, a significant number of patients did not achieve their National Cholesterol Education Program low density lipoprotein concentration goals. Nonetheless, due to the increased risk of rhabdomyolysis with elevated statin concentrations, atorvastatin should be considered a second-line agent. The limited available PIH data supports the fact that pravastatin and atorvastatin are well-tolerated in HIV-infected individuals. More data are needed on the appropriate starting doses, maximum safe doses, role of combination statin-fibrate therapy, documentation of coronary heart disease benefit and incidence of myotoxicity and hepatotoxicity. Pravastatin has an acceptable risk-benefit ratio in PIH, while theoretical toxicity concerns exist with atorvastatin.     

Sodium valproate induced increased frequency of micturition and enuresis

Sodium valproate is a commonly used antiepileptic drug (AED) for control of a broad range of seizures. Adverse drug reactions (ADR) due to sodium valproate range from sedation to nausea, vomiting, weight gain, idiosyncratic adverse effects like hepatotoxicity and life threatening conditions like pancreatitis. We present a case of sodium valproate induced enuresis in child. This ADR of valproate is an underreported ADR and requires special attention of pediatricians as it can interfere with the further treatment of the disease.KEY WORDS: Adverse drug reactions, enuresis, valproate     

Atorvastatin-induced pancreatitis

Drugs account for 1-2% of all cases of pancreatitis. A 58-year-old man was prescribed atorvastatin 10 mg for 6 months for hyperlipidemia. He developed acute abdominal pain and vomiting with epigastric tenderness. Serum lipase and CT scan of the patient suggested the presence of acute pancreatitis. The patient was hospitalized; atorvastatin was stopped and treated symptomatically. He recovered completely within 10 days of drug withdrawal. The causality of the adverse drug reaction according to Naranjo and WHO-UMC Scale was probable. The exact mechanism of pancreatitis due to atorvastatin is not known. It may be a class effect of HMG CoA reductase inhibitors as it had been reported with other statins too. The definite causal relationship is difficult to establish, as rechallenge with the suspected drug was not done due to ethical consideration.     

Recommendations for the use of the acetaminophen hepatotoxicity model for mechanistic studies and how to avoid common pitfalls

Acetaminophen (APAP) is a widely used analgesic and antipyretic drug, which is safe at therapeutic doses but can cause severe liver injury and even liver failure after overdoses. The mouse model of APAP hepatotoxicity recapitulates closely the human pathophysiology. As a result, this clinically relevant model is frequently used to study mechanisms of drug-induced liver injury and even more so to test potential therapeutic interventions. However, the complexity of the model requires a thorough understanding of the pathophysiology to obtain valid results and mechanistic information that is translatable to the clinic. However, many studies using this model are flawed, which jeopardizes the scientific and clinical relevance. The purpose of this review is to provide a framework of the model where mechanistically sound and clinically relevant data can be obtained. The discussion provides insight into the injury mechanisms and how to study it including the critical roles of drug metabolism, mitochondrial dysfunction, necrotic cell death, autophagy and the sterile inflammatory response. In addition, the most frequently made mistakes when using this model are discussed. Thus, considering these recommendations when studying APAP hepatotoxicity will facilitate the discovery of more clinically relevant interventions.     

Cytochrome P450 drug interactions within the HMG-CoA reductase inhibitor class: are they clinically relevant?

The present review outlines the clinical relevance of pharmacokinetic drug interactions within the HMG-CoA reductase inhibitor class. These interactions can result in markedly increased or decreased plasma concentrations of some drugs within this class. However, the relationship between altered plasma concentrations and adverse effects or toxicity may not be linear. It is likely that other variables affect this concentration-effect relationship including: rapid changes in the concentration, concomitant lipid-lowering therapy or host genetic factors that code for different forms or amounts of metabolising enzymes and drug receptors. It is not currently possible to predict which patients will manifest clinically important drug-drug interactions, nor what concentration of an HMG-CoA reductase inhibitor will cause rhabdomyolysis. Thus, until prescribers have better scientific information from which to develop a 'therapeutic range' for each agent, caution should be exercised. In particular, patients taking a CYP3A4-metabolised agent, e.g. atorvastatin, simvastatin and lovastatin, should not be started on a CYP3A4 inhibitor or inducer without close monitoring.     

Enhancement of the predicted drug hepatotoxicity in gel entrapped hepatocytes within polysulfone-g-poly (ethylene glycol) modified hollow fiber

Collagen gel-based 3D cultures of hepatocytes have been proposed for evaluation of drug hepatotoxicity because of their more reliability than traditional monolayer culture. The collagen gel entrapment of hepatocytes in hollow fibers has been proven to well reflect the drug hepatotoxicity in vivo but was limited by adsorption of hydrophobic drugs onto hollow fibers. This study aimed to investigate the impact of hollow fibers on hepatocyte performance and drug hepatotoxicity. Polysulfone-g-poly (ethylene glycol) (PSf-g-PEG) hollow fiber was fabricated and applied for the first time to suppress the drug adsorption. Then, the impact of hollow fibers was evaluated by detecting the hepatotoxicity of eight selected drugs to gel entrapped hepatocytes within PSf and PSf-g-PEG hollow fibers, or without hollow fibers. The hepatocytes in PSf-g-PEG hollow fiber showed the highest sensitivity to drug hepatotoxicity, while those in PSf hollow fiber and cylindrical gel without hollow fiber underestimated the hepatotoxicity due to either drug adsorption or low hepatic functions. Therefore, the 3D culture of gel entrapped hepatocytes within PSf-g-PEG hollow fiber would be a promising tool for investigation of drug hepatotoxicity in vitro.     

Clinical and causality assessment in herbal hepatotoxicity

Introduction: Herbal hepatotoxicity represents a poorly understood, neglected and multifaceted disease with numerous confounding variables and missing established causality in the majority of cases. This review discusses overt shortcomings in its clinical and causality assessment and suggests improvements.

Areas covered: A selective literature search of PubMed using the terms herbal hepatotoxicity, herb-induced liver injury, drug hepatotoxicity and drug-induced liver injury was performed to identify published case reports, spontaneous case reports, case series and review articles regarding hepatotoxicity due to herbs, herbal drugs and herbal dietary supplements. Covered areas focused on confounding variables related to the documentation of the herbal product and the clinical course, hepatotoxicity and reexposure criteria, temporal association, comedication and alternative causes with special attention to preexisting diseases of the liver, bile ducts and the pancreas. Of particular interest were recent discussions of approaches designed and validated for hepatotoxicity causality, such as the scale of CIOMS (Council for International Organizations of Medical Sciences).

Expert opinion: The authors call for substantial improvements in data quality of herbal products and case characteristics and strongly recommend using the CIOMS scale to assess causality in suspected herbal hepatotoxicity.     

Solidified Self-Nanoemulsifying Formulation for Oral Delivery of Combinatorial Therapeutic Regimen: Part II In vivo Pharmacokinetics,Antitumor Efficacy and Hepatotoxicity

Purpose

The present work focuses on the in vivo evaluation of tamoxifen and quercetin combination loaded into solid self-nanoemulsifying drug delivery system (s-Tmx-QT-SNEDDS).

Methods

Lyophilization was employed to prepare s-Tmx-QT-SNEDDS using Aerosil 200 as carrier. The developed formulation was evaluated for in vitro cell cytotoxicity, in vivo pharmacokinetics, antitumor efficacy and toxicity studies.

Results

In vivo pharmacokinetics revealed ~8-fold and ~4-fold increase in oral bioavailability of tamoxifen and quercetin, respectively as compared to free counterparts. s-Tmx-QT-SNEDDS exhibited significantly higher cell cytotoxicity, as compared to free drug combination revealing ~32-fold and ~22-fold higher dose reduction index for tamoxifen and quercetin, respectively estimated using median effect dose analysis. s-Tmx-QT-SNEDDS could suppress tumor growth in DMBA induced tumor bearing animals by ~80% in contrast to ~35% observed with tamoxifen citrate. The significant appreciation in antitumor efficacy was further supported by normalized levels of tumor angiogenesis markers (MMP-2 and MMP-9). Finally, complete obliteration in tamoxifen induced hepatotoxicity was observed upon administration of developed formulation in contrast to that of clinically available tamoxifen citrate when measured as function of hepatotoxicity markers and histopathological changes.

Conclusions

In nutshell, co-encapsulation of quercetin with tamoxifen in solid SNEDDS poses great potential in improving the therapeutic efficacy and safety of tamoxifen.     

Treatment of Relapsed Chronic Subdural Hematoma in Four Young Children with Atorvastatin and Low-dose Dexamethasone

Chronic subdural hematoma (CSDH) can develop in children in rare cases. Burr-hole drainage (BHD) is the treatment of choice, but it is associated with a high rate of recurrence. This report describes four cases of pediatric patients (1–7 yrs of age) with post-BHD relapsed CSDH who were successfully treated with a drug regimen that included 2.5–5 mg atorvastatin daily combined with dexamethasone with stepwise-decreasing dosing for a total of 4 weeks. After 4 weeks of treatment, the hematoma was completely resolved in three patients and significantly reduced in one patient. During the treatment, no patient reported clinically significant adverse events. No patient experienced hematoma relapse during the follow-up period that lasted for up to 4 years. This case report suggests the need for a randomized placebo-controlled trial to evaluate this drug regimen for nonsurgical treatment of patients with relapsed CSDH.     

Review article: drug hepatotoxicity

Background Drug toxicity is the leading cause of acute liver failure in the United States. Further understanding of hepatotoxicity is becoming increasingly important as more drugs come to market. Aims (i) To provide an update on recent advances in our understanding of hepatotoxicity of select commonly used drug classes. (ii) To assess the safety of these medications in patients with pre‐existing liver disease and in the post‐liver transplant setting. (iii) To review relevant advances in toxicogenomics which contribute to the current understanding of hepatotoxic drugs. Methods A Medline search was performed to identify relevant literature using search terms including ‘drug toxicity, hepatotoxicity, statins, thiazolidinediones, antibiotics, antiretroviral drugs and toxicogenomics’. Results Amoxicillin‐clavulanic acid is one of the most frequently implicated causes of drug‐induced liver injury worldwide. Statins rarely cause clinically significant liver injury, even in patients with underlying liver disease. Newer thiazolidinediones are not associated with the degree of liver toxicity observed with troglitazone. Careful monitoring for liver toxicity is warranted in patients who are taking antiretrovirals, especially patients who are co‐infected with hepatitis B and C. Genetic polymorphisms among enzymes involved in drug metabolism and HLA types may account for some of the differences in individual susceptibility to drug hepatotoxicity. Conclusions Drug‐induced hepatotoxicity will remain a problem that carries both clinical and regulatory significance as long as new drugs continue to enter the market. Future results from ongoing multicentre collaborative efforts may help contribute to our current understanding of hepatotoxicity associated with drugs.     

Clopidogrel: A possible exacerbating factor for psoriasis

A 64-year-old man developed palmoplantar pustulosis eventuating into palmoplantar pustular psoriasis following treatment with diltiazem, atenolol, aspirin and atorvastatin for suspected coronary artery disease (CAD). Treatment for psoriasis, stopping atenolol and substituting aspirin with clopidogrel did not benefit. Subsequently, he stopped all his drugs and did not develop psoriasis or symptoms/signs of CAD. Re-challenge with oral clopidogrel precipitated his skin lesions. This case has implications for patients having psoriasis and cardiovascular comorbidity where clopidogrel/ticlopidine or aspirin may not be a useful alternative.KEY WORDS: Adverse drug reactions, antiplatelet therapy, clopidogrel, psoriasis triggers, pustular psoriasis     

Evaluation of pharmacokinetic interactions between bicyclol and co-administered drugs in rat and human liver microsomes in vitro and in rats in vivo

1. Bicyclol is a new synthetic anti-hepatitic drug and primarily metabolized by CYP3A. The aim of this study was to evaluate the pharmacokinetic interactions between bicyclol and co-administered drugs including metformin, pioglitazone, atorvastatin, fenofibrate, Cyclosporin A (CsA), and tacrolimus in rat and human liver microsomes (RLMs/HLMs) in vitro and in rats in vivo.

2. The depletion rate of bicyclol in RLMs was significantly inhibited by 44.8% and 35.5% after preincubation with pioglitazone and fenofibrate while the metabolite formation rate of bicyclol in HLMs was inhibited by 26.1% and 23.9% after preincubation and coincubation with tacrolimus, and by 20.2% after preincubation with CsA. Conversely, preincubation and coincubation with bicyclol significantly inhibited the depletion rate of pioglitazone in RLMs by 34.1% and 27.1%, respectively, and the formation rate of para- and ortho-hydroxy atorvastatin in RLMs and HLMs by 20.6–36.2%. There were no significant pharmacokinetic interactions between bicyclol and pioglitazone in rats after a single or multiple oral treatment.

3. As the selected inhibitory drug concentrations in vitro were significantly higher than those in clinical settings and the maximum inhibition rate did not exceed 50%, the clinically significant interaction between bicyclol and these co-administered drugs in humans is predicted less likely to happen.

     

比卡鲁胺致肝损害一例并文献复习

目的 提高对比卡鲁胺肝脏毒性的认识.方法 报告1例因应用比卡鲁胺引起肝脏损害的病例,并进行文献复习.结果 患者应用比卡鲁胺2周后出现肝脏损害,停药并经治疗后好转.结论 虽然比卡鲁胺引起肝损害的发生率不高,但临床医师一定要关注该药潜在的肝脏毒性,一旦确认药物性肝损害,立即停用并做出相应处理.