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Viral hepatitis.
Published in Michael JG Farthing, Anne B Ballinger, Drug Therapy for Gastrointestinal and Liver Diseases, 2019
Eleanor Barnes, George Webster, Geoffrey M Dusheiko
Adefovir dipivoxil is an adenosine nucleotide analogue, which is now in Phase III trials in HBV infection. Preliminary data suggest that the development of resistance may be less common than with lamivudine. Renal toxicity has been demonstrated in clinical trials in HIV infection when given in high doses.
Lamivudine
Published in M. Lindsay Grayson, Sara E. Cosgrove, Suzanne M. Crowe, M. Lindsay Grayson, William Hope, James S. McCarthy, John Mills, Johan W. Mouton, David L. Paterson, Kucers’ The Use of Antibiotics, 2017
Jennifer Audsley, Michelle Giles, Sharon R. Lewin
Adefovir disoproxil has similar efficacy in vitro against wild-type and the four major lamivudine-resistant strains of hepatitis B virus (rtL180M + rtM204V; rt173L + rtL180M + rtM204V; rtM204I; rtL180M + M204I) (Yang et al., 2005). However, other in vitro data have suggested that adefovir is less active against the lamivudine triple-mutant rt173L + rtL180M + rtM204V (Lai et al., 2006) the clinical setting, adefovir has been effective against lamivudine-resistant hepatitis B virus alone or in combination, with on-going lamivudine treatment in both hepatitis B virus monoinfection and HIV/hepatitis B virus coinfection (Benhamou et al., 2001; Perrillo et al., 2004; Peters et al., 2004; see Chapter 255, Adefovir dipivoxil).
Sexually acquired viral hepatitis B and C
Published in Shiv Shanker Pareek, The Pictorial Atlas of Common Genito-Urinary Medicine, 2018
Acute hepatitis B usually resolves spontaneously, so no treatment is required. If a patient has chronic, active hepatitis B with replicating virus, the following treatments should be administered: interferon alpha-2b (an immune modulator which helps the patients immune system fight the infection) 3 million units (MU) – administered intramuscular three times per weekalternatively: pegylated interferon alpha-2b (a long-acting version) 180 pg – administered intramuscular once weeklyantiviral drugs (these stop the virus replicating):– entecavir 0.5 mg orally once daily, available as a tablet or liquid suspension (if previously resistant to lamivudine, the dose should be 1 g once daily).– adefovir dipivoxil 10 mg orally once daily (not recommended for children under 12 years of age).– telbivudine 600 mg orally once daily, available as a tablet or liquid suspension (not recommended for children under 16 years of age).– tenofovir disoproxil fumarate 300 mg orally once daily (not recommended for children or adolescents with hepatitis B).– lamivudine 100 mg orally once daily in adults. For children two years of age and above, dose at 3 mg/kg bodyweight orally once daily, to a maximum of 100 mg per day.
Early recurrence after radiofrequency ablation for hepatocellular carcinoma: a multicenter retrospective study on definition, patterns and risk factors
Published in International Journal of Hyperthermia, 2021
Yi Yang, Yujing Xin, Feng Ye, Ning Liu, Xinyuan Zhang, Yanan Wang, Xiao Li, Qingsheng Fan, Xiang Zhou, Yi Chen
Post-operative CE imaging such as MRI, CT, or ultrasound were performed to confirm complete ablation. If residual tumor tissue was still present, additional RFA procedures were immediately performed to achieve complete ablation in one procedure [20]. A minimal ablative margin > 0.5 cm beyond the tumor in all directions or/and absence of arterial contrast enhancement and portal venous washout within the ablation zone suggestive of residual tumor one month after ablation was/were considered as complete ablation [25,26,29,30]. Patients were followed-up every 3 months in the first year after RFA and every six months in the subsequent years until tumor recurrence or death. The last follow-up date for this study was September 30th, 2019. Each follow-up visit consisted of clinical history, physical examination, serum AFP levels and CE MRI. Patients with chronic hepatitis B virus (HBV) infection and HBV DNA level >1000 copies/mL were treated with lamivudine, adefovir dipivoxil or entecavir daily [12]. Patients with chronic hepatitis C virus (HCV) infection were treated with interferon and ribavirin [31]. HCC recurrence was treated by the multidisciplinary approach, which included surgical resection, repeat RFA, transarterial chemoembolization (TACE), or systemic therapy (i.e., sorafenib or FOLFOX4 regimen chemotherapy).
Improving cellular uptake of therapeutic entities through interaction with components of cell membrane
Published in Drug Delivery, 2019
Renshuai Zhang, Xiaofei Qin, Fandong Kong, Pengwei Chen, Guojun Pan
Pro-drug strategy has been used to improve the cell uptake of small molecules through increasing lipophilicity. At present, about 10% of drugs approved worldwide are administered as pro-drugs (Hajnal et al., 2016). In most cases, increasing lipophilicity is one of the important purposes for using of pro-drugs. In many small molecule drugs, charged groups such as the carboxylic acids and phosphates exist as indispensable functional groups for their pharmacological activity. However, their presence reduces the lipophilicity, and thus prevents the passage of molecules through membranes by simple diffusion. Masking these charged groups with aliphatic alcohol via esterification reaction is the most widely used strategy to enhance the lipophilicity, and thus the passive membrane permeability (Rautio et al., 2008). Oseltamivir is the ester pro-drug of the antiviral molecule oseltamivir carboxylate. Previous study showed that the oral bioavailability of oseltamivir increased to 80% after ester modification, while that of oseltamivir carboxylate is less than 5% (Doucette & Aoki, 2001). Adefovir dipivoxil is an oral pro-drug of the nucleotide analog adefovir. The study proved that the oral bioavailability increased to 30–45%, after esterifying the phosphate group. More examples on ester pro-drugs that enhance oral absorption of predominantly poorly permeable and polar parent drugs can be seen in Beaumont et al.’s review (Beaumont et al., 2003).
Pharmacotherapy options for managing hepatitis B in children
Published in Expert Opinion on Pharmacotherapy, 2021
Haruki Komatsu, Ayano Inui, Sachiyo Yoshio, Tomoo Fujisawa
Adefovir dipivoxil is rapidly converted to adefovir after oral administration. Adefovir is a nucleotide analogue, and the intracellular metabolite, adefovir diphosphate, inhibits the priming of reverse transcription [6,86]. Although adefovir also has antiviral activity against HIV, a high dose (≥10-fold greater than that for HBV), which causes nephrotoxicity, is required for the suppression of HIV replication [43,89,90]. In a randomized controlled trial, there was a significant difference in the primary efficacy endpoint (low HBV DNA level and normalization of the ALT level) between children (≥12 to ˂18 years) with 48-week treatment (23%) and placebo controls (0%) (Table 5). Adefovir-associated mutations were not detected in the treated children [91].