Acute Liver Failure among Patients on Efavirenz-Based Antiretroviral Therapy

Challenges and Opportunities for Consideration of Efavirenz Drug Repurposing for Alzheimer's Disease Therapeutics

Therapeutic research and development for Alzheimer's disease (AD) has been an area of intense research to alleviate memory loss and neurodegeneration. There is growing interest in drug repositioning and repurposing strategies for FDA-approved medications as potential candidates that may further advance AD therapeutics. The FDA drug efavirenz has been investigated as a candidate drug for repurposing as an AD medication. The proposed mechanism of action of efavirenz (at low doses) is the activation of the neuron-specific enzyme CYP46A1 that converts excess brain cholesterol into 24-hydroxycholesterol (24-HC) that is exported to the periphery. Efavirenz at a low dose was found to improve memory deficit in the 5XFAD model of AD that was accompanied by elevated 24-HC and reduction in Aβ; furthermore, efavirenz reduced pTau and excess cholesterol levels in human iPSC-derived Alzheimer's neurons. The low dose of efavirenz used in the AD mouse model to increase 24-HC contrasts with the use of more than 100-fold higher doses of efavirenz for clinical treatment of human immunodeficiency virus (HIV) through inhibition of reverse transcriptase. Low doses of efavirenz may avoid neurotoxic adverse effects that occur at high efavirenz doses used for HIV treatment. This review evaluates the drug properties of efavirenz with respect to its preclinical data on regulating memory deficit, pharmacokinetics, pharmacodynamics, metabolites, and genetic variabilities in drug metabolism as well as its potential adverse effects. These analyses discuss the challenges and questions that should be addressed in future studies to consider the opportunity for low dose efavirenz as a candidate for AD drug development.

Chemoinformatic Design and Profiling of Derivatives of Dasabuvir, Efavirenz, and Tipranavir as Potential Inhibitors of Zika Virus RNA-Dependent RNA Polymerase and Methyltransferase

Zika virus (ZIKV) infection is one of the mosquito-borne flaviviruses of human importance with more than 2 million suspected cases and more than 1 million people infected in about 30 countries. There are reported inhibitors of the zika virus replication machinery, but no approved effective antiviral therapy including vaccines directed against the virus for treatment or prevention is currently available. The study investigated the chemoinformatic design and profiling of derivatives of dasabuvir, efavirenz, and tipranavir as potential inhibitors of the zika virus RNA-dependent RNA polymerase (RdRP) and/or methyltransferase (MTase). The three-dimensional (3D) coordinates of dasabuvir, efavirenz, and tipranavir were obtained from the PubChem database, and their respective derivatives were designed with DataWarrior-5.2.1 using an evolutionary algorithm. Derivatives that were not mutagenic, tumorigenic, or irritant were selected; docked into RdRP and MTase; and further subjected to absorption, distribution, metabolism, excretion, and toxicity (ADMET) evaluation with Swiss-ADME and pkCSM web tools. Some of the designed compounds are Lipinski's rule-of-five compliant, with good synthetic accessibilities. Compounds 20d, 21d, 22d, and 1e are nontoxic with the only limitation of CYP1A2, CYP2C19, and/or CYP2C9 inhibition. Replacements of -CH₃ and -NH- in the methanesulfonamide moiety of dasabuvir with -OH and -CH₂- or -CH₂CH₂-, respectively, improved the safety/toxicity profile. Hepatotoxicity in 5d, 4d, and 18d is likely due to -NH- in their methanesulfonamide/sulfamic acid moieties. These compounds are potent inhibitors of N-7 and 2'-methylation activities of ZIKV methyltransferase and/or RNA synthesis through interactions with amino acid residues in the priming loop/"N-pocket" in the virus RdRP. Synthesis of these compounds and wet laboratory validation against ZIKV are recommended.

HIV and Antiretroviral Therapy Are Independently Associated with Cardiometabolic Variables and Cardiac Electrical Activity in Adults from the Western Cape Region of South Africa

Cardiovascular-related complications are on the rise in people with HIV/AIDS (PWH); however, the relationship among HIV and antiretroviral therapy (ART)-related parameters, cardiovascular risk, and cardiac electrical activity in PWH remain poorly studied, especially in sub-Saharan African populations. We investigated whether HIV and ART are associated with cardiometabolic and cardiac electrical activity in PWH from Worcester in the Western Cape Province, South Africa. This was a cross-sectional study with HIV-negative (HIV-, n = 24) and HIV-positive on ART (HIV+/ART+, n = 63) participants. We obtained demographic, lifestyle, and medical history data and performed anthropometric, clinical assessments, and blood/urine biochemistry. We performed multiple stepwise linear regression analyses to determine independent associations among HIV, ART, cardiometabolic, and electrocardiographic (ECG) variables. HIV+/ART+ independently associated with a lower body mass index (p = 0.004), elevated gamma-glutamyl transferase levels (β: 0.333 (0.130-0.573); p = 0.002), and elevated alanine aminotransferase levels (β: 0.427 (0.224-0.629); p < 0.001) compared to HIV-. Use of second-line ART was positively associated with high-sensitivity C-reactive protein (p = 0.002). Although ECG parameters did not differ between HIV- and HIV+/ART+, viral load positively associated with p-wave duration (0.306 (0.018-0.594); p = 0.038), and longer HIV duration (≥5 years) with ST-interval (0.270 (0.003-0.537); p = 0.047) after adjusting for confounding factors. Our findings suggest that HIV and ART are associated with mixed effects on this population's cardiometabolic profile and cardiac electrical activity, underpinning the importance of cardiovascular risk monitoring in PWH.

Substance Use, Highly Active Antiretroviral Therapy, and Liver Enzymes: Evidence From a Cross-Sectional Study of HIV-Infected Adult Patients Without Comorbidities on HAART in the University of Port Harcourt Teaching Hospital

This study applied a structural equation modeling (SEM) to evaluate the role of substance use (alcohol, smoking, and trado-medicine use) to changes in the liver enzymes (AST, ALT, and ALP) levels in HIV-infected adult patients on a highly active antiretroviral treatment (HAART) for not <1 year. The study was a cross-sectional, part of a randomized comparative trial (Ref: UPH/CEREMAD/REC/19), involving 129 (46 males and 83 females) HIV-infected adult patients. Liver enzyme levels were determined from analyzed blood samples using the Clinical Chemistry Analyser (VS10) manufactured by Vitro Scient, while the study determined substance use using a reliable (Cronbach alpha = 0.805) rapid-exploratory survey questionnaire. Liver enzyme values were further categorized into: normal or abnormal using normal reference ranges (ALT = 7–55 U/L, AST = 8–48 U/L, and ALP = 40–129 U/L). STATGRAPHICS V16.1.11 (StatPoint Tech., Inc.) and SPSS (IBM® Amos V21.0.0, USA) were used to analyze the data. Among the HIV-HAART patients, 27.9% were alcohol users, 20.9% smokers, and 20.1% trado-medicine users. In addition, ALP (71.3%) abnormality was higher than ALT (34.9%) and AST (28.7%). The result from the SEM provided only a partial support for our hypotheses of direct substance use effects on the liver enzyme levels and abnormalities; with a direct association of alcohol with an elevated AST (b = 0.170, p = 0.05) and smoking with a higher AST (b = 0.484, p < 0.01) and ALT (b = 0.423, p < 0.01) values. Trado-medicine use was not directly associated with enzyme elevation and abnormality. In conclusion, ALP abnormality was the most common, and there is a close association between an elevated ALT and AST, with or without an elevated ALP. The study found that HIV-HAART patients who drink or smoke will have at least one or more abnormal transaminases. The possible explanation to the increased risk among HIV-HAART patients could be associated with the metabolic pressures and supra-additive effects on the livers.

Derangement of Liver Enzymes, Hyperglycemia, Anemia, and Associated Factors among HIV-Infected Patients Treated with Tenofovir Disoproxil Fumarate-Based Regimen in Ethiopia: A Prospective Cohort Study

Hepatotoxicity was found in different case reports and studies in tenofovir disoproxil fumarate- (TDF-) based regimen. However, there was no data regarding liver enzymes, glucose, and hemoglobin in Ethiopian patients receiving TDF-based regimen. The aim of this study was to determine elevated liver enzymes and its associated factors as well as elevated fasting plasma glucose and anemia. A hospital-based observational prospective cohort study was conducted on conveniently selected 63 patients in Tikur Anbessa Specialized Hospital (TASH) from January to September 2019. Laboratory values were determined at pre-TDF-based regimen baseline and six-month follow-up. The data was analyzed by using SPSS version 21.0, and multivariate logistic regression was used to determine associated factors with elevated liver enzymes. The overall elevated liver enzymes were found in 26 (41.3%) participants. From this, elevated alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) comprise 3 (4.8%), 3 (4.8%), and 20 (31.8%), respectively. Elevated fasting plasma glucose (FPG) was found in 9 (14.3%) and 14 (22.2%) of participants at baseline and six-month visit, respectively. At six-month visit, 4 (6.4%) of participants experienced anemia. The mean value of ALP and FPG at six months was significantly higher than their respective baseline mean values (mean difference (MD) = +63.38, 95% CI (39.84, 86.92), p = 0.0001; MD = +6.64, 95% CI (2.63, 10.64), p = 0.002, respectively). The mean value of ALT, AST, and Hg at six months was slightly increased compared to their respective baseline mean values, but the difference was not significant. In multivariate analysis, only female sex was significantly associated with elevated ALP (AOR = 4.5, 95% CI (1.03, 19.6), p = 0.045). Overall mild and moderate hepatotoxicity was found to be high (26, 41.3%) in the present study, and from this, the majority was comprised by elevated ALP (20, 31.8%). The proportion of participants with hyperglycemia was increased at the end of follow-up compared to its baseline value, but anemia was not. Female sex was significantly associated with elevated ALP. This study warrants monitoring of liver enzymes and glucose in TDF-based regimen.

Drug-Induced Liver Injury: Highlights of the Recent Literature

Drug-induced liver injury (DILI), herbal-induced liver injury, and herbal and dietary supplement (HDS)-induced liver injury are an important aspect of drug safety. Knowledge regarding responsible drugs, mechanisms, risk factors, and the diagnostic tools to detect liver injury have continued to grow in the past year. This review highlights what we considered the most significant publications from among more than 1800 articles relating to liver injury from medications, herbal products, and dietary supplements in 2017 and 2018. The US Drug-Induced Liver Injury Network (DILIN) prospective study highlighted several areas of ongoing study, including the potential utility of human leukocyte antigens and microRNAs as DILI risk factors and new data on racial differences, the role of alcohol consumption, factors associated with prognosis, and updates on the clinical signatures of autoimmune DILI, thiopurines, and HDS agents. Novel data were also generated from the Spanish and Latin American DILI registries as well as from Chinese and Korean case series. A few new agents causing DILI were added to the growing list in the past 2 years, including sodium-glucose co-transporter-2 inhibitors, as were new aspects of chemotherapy-associated liver injury. A number of cases reported previously described hepatotoxins confirmed via the Roussel Uclaf Causality Assessment Method (RUCAM; e.g., norethisterone, methylprednisolone, glatiramer acetate) and/or the DILIN method (e.g., celecoxib, dimethyl fumarate). Additionally, much work centered on elucidating the pathophysiology of DILI, including the importance of bile salt export pumps and immune-mediated mechanisms. Finally, it must be noted that, while hundreds of new studies described DILI in 2017-2018, the quality of such reports must always be addressed. Björnsson reminds us to remain very critical of the data when addressing the future utility of a study, which is why it is so important to adhere to a standardized method such as RUCAM when determining DILI causality. While drug-induced hepatotoxicity remains a diagnosis of exclusion, the diverse array of publications that appeared in 2017 and 2018 provided important advances in our understanding of DILI, paving the way for our improved ability to make a more definitive diagnosis and risk assessment.