Adefovir dipivoxil-induced Fanconi syndrome and its predictive factors: A study of 28 cases

Mapping Adverse Outcome Pathways for Kidney Injury as a Basis for the Development of Mechanism-Based Animal-Sparing Approaches to Assessment of Nephrotoxicity

In line with recent OECD activities on the use of AOPs in developing Integrated Approaches to Testing and Assessment (IATAs), it is expected that systematic mapping of AOPs leading to systemic toxicity may provide a mechanistic framework for the development and implementation of mechanism-based in vitro endpoints. These may form part of an integrated testing strategy to reduce the need for repeated dose toxicity studies. Focusing on kidney and in particular the proximal tubule epithelium as a key target site of chemical-induced injury, the overall aim of this work is to contribute to building a network of AOPs leading to nephrotoxicity. Current mechanistic understanding of kidney injury initiated by 1) inhibition of mitochondrial DNA polymerase γ (mtDNA Polγ), 2) receptor mediated endocytosis and lysosomal overload, and 3) covalent protein binding, which all present fairly well established, common mechanisms by which certain chemicals or drugs may cause nephrotoxicity, is presented and systematically captured in a formal description of AOPs in line with the OECD AOP development programme and in accordance with the harmonized terminology provided by the Collaborative Adverse Outcome Pathway Wiki. The relative level of confidence in the established AOPs is assessed based on evolved Bradford-Hill weight of evidence considerations of biological plausibility, essentiality and empirical support (temporal and dose-response concordance).

Fanconi syndrome induced by adefovir dipivoxil: a case report and clinical review

More than 150 cases of Fanconi syndrome (FS) or hypophosphatemia osteomalacia induced by low-dose adefovir dipivoxil (ADV) have been reported since 2002, when ADV was introduced for the long-term treatment of hepatitis B virus (HBV) infection. Because the life expectancy of HBV-infected individuals has increased, the adverse effects of long-term treatment with antiviral therapies are increasingly observed, and nephrotoxicity is one of the most severe adverse effects of ADV. Therefore, the number of cases may be far higher than reported. Moreover, ADV-induced FS is often misdiagnosed or diagnosed long after it first develops. ADV-induced FS may seriously decrease patient quality of life and lead to bone fractures and even disability. Although progress has been made in the identification of biomarkers and treatments, few systematic clinical guidelines or clinical reviews for FS induced by ADV have been reported. In this study, we highlighted the recent progress toward understanding of FS induced by ADV, described a clinical case, and summarized the primary characteristics and laboratory findings of this disease.

Adefovir dipivoxil efficiently inhibits the proliferation of pseudorabies virus in vitro and in vivo

Since 2011, highly pathogenic pseudorabies virus (PRV) variants that emerged on many farms in China have posed major economic burdens to the animal industry and have even recently caused several human cases of viral encephalitis. Currently, there are no approved effective drugs to treat PRV associated diseases in humans or pigs. Thus, it is important to develop a new effective drug for the treatment of PRV infection. To this end, we established a novel rapid method to screen drugs against PRV from 1818 kinds of small molecular drugs approved by the FDA. Using this method, we identified 21 kinds of them that can strongly suppress the proliferation of PRV. Mitoxantrone, puromycin dihydrochloride, mitoxantrone hydrochloride and adefovir dipivoxil effectively inhibited PRV in vitro. Of them, only adefovir dipivoxil could potently protect mice against lethal PRV infection. Our work identifies several kinds of potential therapeutics against PRV and may offer important guidance for controlling PRV epidemics and treating associated diseases in humans and animals.

Osteomalacia and renal failure due to Fanconi syndrome caused by long-term low-dose Adefovir Dipivoxil: a case report

Background

Progressive bone pain and fracture and abnormal positron emission tomography combined with a computed tomography are main reasons for the oncologists suspecting bone tumor. During the patient’s medical treatment, the oncologists’ unfamiliarity with adverse reactions to anti-HBV drugs were main reason for the long-term exposure to the drug and the adverse reaction (ADR) experienced by the patient.

Case presentation

A 63-year-old Chinese man had a 27-month history of progressive generalized bone pain combined with spontaneous fractures. Positron emission tomography combined with a computed tomography, revealed an abnormal increase in ribose metabolism and low positron serum inorganic phosphorus concentration (0.7; 0.78–1.65 mmol/L). Serum creatinine level was 252 μmol/L (53–97) μmol/L, and glomerular filtration rate was 22.79 mL/min/1.73 m². The patient was referred to a multidisciplinary clinic to clarify the diagnosis of myeloma or bone tumor for further treatment in 2017. His medical history revealed that he had a 30-year history of chronic hepatitis B infection. He had received lamivudine at a daily dose of 100 mg for 19 years (1990 to 2009), which had been changed to adefovir (10 mg/day) owing to lamivudine resistance in 2009. Based on the changes in the patient’s laboratory markers and the results of emission computed tomography and other radiographic findings, adefovir-induced hypophosphatemic osteomalacia due to acquired renal Fanconi syndrome was suspected by the clinical pharmacist. Considerable clinical improvement was observed after adefovir discontinuation and the administration of entecavir (1.0 mg, every other day).

Conclusion

Fanconi syndrome with osteomalacia can develop in patients with chronic hepatitis B infection being treated with adefovir at a conventional low dosage of 10 mg/day. This case highlights the importance of ADR as a differential diagnosis and the need of pharmacists with drug safety expertise expert in the patient management.

Low-dose adefovir dipivoxil-induced hypophosphatemia osteomalacia in five chronic hepatitis B virus-infected patients. Is low-dose adefovir dipivoxil-induced nephrotoxicity completely reversible?

Adefovir dipivoxil (ADV) is one of the most important nucleostide analogues currently in use for the treatment of chronic hepatitis B virus (HBV) infection. Low-dose ADV-induced nephrotoxicity in most cases was reported to be reversible after the discontinuation of ADV or by decreasing the dose of ADV. In our study, we have 5 documented cases of low-dose ADV-induced hypophosphatemia osteomalacia with or without Fanconi syndrome which were diagnosed in our hospital between 2010 and 2017. Three patients were observed to have a full recovery after the discontinuation of ADV. Two patients had persistently elevated urine β₂-microglobulin levels and out of these two patients, one patient had persistent hypophosphatemia after the cessation of ADV. These cases illustrated that the use of low-dose ADV increased the risk of nephrotoxicity, and in some patients, low-dose ADV-induced nephrotoxicity was not completely reversible. Patients of East Asian origin, especially those with a low body mass index, were prone to a relatively higher risk of developing low-dose ADV-induced nephrotoxicity; therefore, it was worth paying attention to the side effects caused by low-dose ADV.

Hypophosphatemic Osteomalacia Associated with Adefovir-induced Fanconi Syndrome Initially Diagnosed as Diabetic Kidney Disease and Vitamin D Deficiency

A 68-year-old man with type 2 diabetes mellitus and chronic hepatitis B infection was referred to the nephrology department before planned surgery for hepatocellular carcinoma. He had been receiving low-dose adefovir dipivoxil (ADV) for 11 years. Laboratory findings revealed impaired re-absorption in the proximal renal tubules. He had been diagnosed with diabetic kidney disease and osteomalacia due to vitamin D deficiency; thus, ADV was not discontinued until he was referred to us. In this case, concomitant diabetes mellitus and vitamin D deficiency might have prevented the early diagnosis of ADV-induced Fanconi syndrome.

Fuzheng Huayu capsule as an adjuvant treatment for HBV-related cirrhosis: A systematic review and meta-analysis

Fuzheng Huayu (FZHY) capsule, a formulated traditional Chinese medicine product with 6 Chinese herbs, is widely used for HBV-related cirrhosis as an adjuvant treatment. However, the efficacy of FZHY capsule for HBV-induced cirrhosis did not be comprehensively proved by systematic analysis. Our current analysis was aimed to assess the efficacy and safety of FZHY capsule by an evidence-based method. Databases, including China National Knowledge Infrastructure, Wangfang, VIP medicine information system, Pubmed, Embase, and Cochrane Library, were searched, and the randomized controlled trials of FZHY capsule were used for the treatment of HBV-associated liver cirrhosis. Meta-analysis was performed by Review Manager 5.3. The efficacy rate, alanine transaminase (ALT), aspartate aminotransferase (AST), total bilirubin (TBIL), albumin (ALB), Procollagen III protein (PIIIP), hyaluronic acid (HA), laminin (LN), Collagen C Type IV (IV-C), Child-Pugh score, portal vein diameter, spleen thickness, HBeAg negative conversion rate, and HBV-DNA negative conversion rate were systematically assessed. The Cochrane Risk of Bias tool was used to evaluate the methodological quality of eligible studies. Nineteen studies with 1,769 patients were included in the meta-analysis. Compared to conventional treatment, FZHY capsule was effective by increasing the efficacy. FZHY capsule was more efficient in improving ALT, AST, TBIL, PIIIP, HA, LN, IV-C, Child-Pugh grading score, portal vein diameter, spleen thickness, and HBV-DNA negative conversion rate with no serious adverse reactions. Nevertheless, a variety of well-designed randomized controlled trials are needed to confirm these findings since small samples were applied in the previous studies.

Kushenin combined with adefovir dipivoxil affects the HBV-DNA load in serum, immune functions and liver functions of patients with chronic hepatitis B

This study aimed to explore the effect of kushenin combined with adefovir dipivoxil on the load of hepatitis B virus DNA (HBV-DNA) in serum, in immune functions and in liver functions of patients with chronic hepatitis B. A sample of 80 patients with chronic hepatitis B was selected who were admitted to Weifang People's Hospital for treatment between January, 2013 and December, 2015. They were divided into the observation group (n=40) and the control group (n=40). The patients in both groups received adefovir dipivoxil, while those in the observation group additionally received the kushenin. Variations in HBV-DNA load and transforming growth factor-β1 (TGF-β1) in the two groups were detected before intervention, at 1 month, 3 months and 6 months after intervention. In addition, after intervention, we also observed the changes in CD4+, CD8+ and CD4+/CD8+, as well as the levels of immune globulin. Furthermore, in these two groups, we detected the changes in endotoxin in serum before and after intervention, the liver function after intervention, and the variations of hyaluronic acid (HA) and type III procollagen (PCIII) before and after intervention which were used to serve as the indicators for hepatic fibrosis. Results showed that at one month, 3 months and 6 months after intervention, HBV-DNA load and the level of TGF-β1 in the observation group were lower than those in the control group (P<0.05). In the observation group, the HBV-DNA load at 6 months after intervention was the lowest, sequentially followed by the levels at 3 months, at 1 month and before intervention (P<0.05). After intervention, the levels of CD4+ and CD8+ and CD4+/CD8+ in the observation group were higher than those in the control group (P<0.05). Moreover, the levels of immunoglobulin M (IgM), immunoglobulin G (IgG) and immunoglobulin A (IgA) were elevated in the observation group compared to the levels in the control group (P<0.05). Additionally, the level of endotoxin in serum, the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and total bilirubin (TBil). Besides, after intervention, the levels of HA and PCIII in the observation group were found to be lower than those in the control group before and after intervention (P<0.05). This study concludes that, for patients with chronic hepatitis B, kushenin combined with adefovir dipivoxil can remarkably decrease the HBV-DNA load, improve their immunity, ameliorate the liver function and delay the onset of liver cirrhosis.

Long-term adefovir therapy may induce Fanconi syndrome: A report of four cases

Fanconi syndrome is a rare disease characterized by dysfunction of the proximal renal tubules as a result of various pathogenic events. Drug-induced Fanconi syndrome may be neglected or misdiagnosed, which increases the level of suffering. The aim of the present study was to conduct an investigation into the effects of adefovir (ADV)-induced Fanconi syndrome. Four typical cases of Fanconi syndrome caused by long-term ADV therapy (2-9 years) were diagnosed at our hospital. A complete medical and therapy history was collected from all four patients prior to a physical examination. Laboratory and diagnostic examinations were also conducted. Following this, the patients were diagnosed and a treatment regimen was decided upon. Outcomes of the treatment regimen were observed. Common manifestations of all the four patients were: Renal tubular reabsorption dysfunction; imbalanced electrolyte acid-base ratio; elevated cystatin C levels; severe hypophosphatemia and diffused systemic pain; osteoporosis; and difficultly walking. When ADV was replaced with supportive treatment, all the four patients exhibited symptom relief. These findings indicate that long-term ADV therapy may induce Fanconi syndrome. For patients with a history of such therapy, the possibility of Fanconi syndrome should be assessed and monitored closely for indicators, including altered glomerular and renal tubular function. Once diagnosed, the agent should be immediately discontinued and prompt symptomatic treatment should be administered.