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Hepatic disorders in pregnancy
Published in Hung N. Winn, Frank A. Chervenak, Roberto Romero, Clinical Maternal-Fetal Medicine Online, 2021
Ghassan M. Hammoud, Jamal A. Ibdah
The current (2009) Federal Drug Administration (FDA)-approved therapy for HBV in nonpregnant patients include subcutaneous injection of interferon/pegylated interferon alpha and orally administered nucleoside/tide analogs such as Lamivudine, Adefovir, Entecavir, Telbivudine, and Tenofovir (21). Interferon is considered FDA category C drug in pregnancy and is not recommended. Lamivudine, an oral nucleoside analog, classified as FDA category C drug in terms of safety, is given to mothers with high HBV DNA during the second and third trimesters to reduce the risk of transmission at the time of delivery. It is generally not recommended for use against HBV in the first trimester of pregnancy. However, potential benefits may justify the potential risk. The data on adefovir, entecavir, telbivudine, and tenofovir safety are limited in pregnancy. Although HBV may be found in breast milk, a study comparing breast-fed versus non-breast-fed babies of seropositive mothers demonstrated no difference in the infection rate.
Adefovir Dipivoxil
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
Wai-Kay Seto, Ching-Lung Lai, Man-Fung Yuen
In vitro studies investigating adefovir in two-drug combinations with penciclovir or lamivudine show the antiviral effects to be additive or synergistic against duck HBV (Colledge et al., 2000). Adefovir also has additive antiviral activity when combined with lamivudine, entecavir, or telbivudine against cell lines expressing high levels of wild-type HBV (HepG2 49–29) (Dando and Plosker, 2003).
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.
Pharmacotherapy options for managing hepatitis B in children
Published in Expert Opinion on Pharmacotherapy, 2021
Haruki Komatsu, Ayano Inui, Sachiyo Yoshio, Tomoo Fujisawa
Although the emergence of drug-resistant mutants was rare in a long-term treatment, adefovir was discontinued in 38% of the children due to a poor virologic response [92]. In adults, the emergence of mutants that are resistant to adefovir occurs in 0% and 20%–29% of adults at 1 year and 5 years after the initiation of treatment, respectively [14,93]. Adefovir is effective against lamivudine-resistant mutants, and thus adefovir is indicated for chronically infected patients who are treatment-naïve or who have developed lamivudine-resistant mutants. Add-on adefovir with ongoing lamivudine was as effective as entecavir for the reduction of HBV DNA in children who developed lamivudine-resistant mutants [94]. Similar to lamivudine, because of the development of antivirals with a high genetic barrier to resistance, the role of adefovir is also limited in the treatment of chronic HBV infection.
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).
Combination of entecavir with thymosin alpha-1 in HBV-related compensated cirrhosis: a prospective multicenter randomized open-label study
Published in Expert Opinion on Biological Therapy, 2018
Xiaoning Wu, Yiwen Shi, Jialing Zhou, Yameng Sun, Hongxin Piao, Wei Jiang, Anlin Ma, Yongpeng Chen, Mingyi Xu, Wen Xie, Jun Cheng, Shibin Xie, Jia Shang, Jilin Cheng, Qing Xie, Huiguo Ding, Xuqing Zhang, Lang Bai, Mingxiang Zhang, Bingqiong Wang, Shuyan Chen, Hong Ma, Xiaojuan Ou, Jidong Jia, Hong You
In this multicenter, prospective and randomized open-label cohort study, patients were randomly assigned to receive entacavir (0.5 mg per day) or combination with Ta-1 (1.6 mg twice per week subcutaneously injection) for 52 weeks after 26 weeks’ of entecavir treatment (0.5 mg per day for all the patients). The study is planned for at least two years. After the combination phase, all the patients continued to receive entecavir treatment (0.5 mg per day) (Figure 1). Patients with primary non-response after 26 weeks’ of treatment were recommended to add entecavir to 1 mg daily or add on adefovir 10 mg per day or shift to tenovir 300 mg daily as a rescue therapy. Follow-up and treatment were continued for patients who reached a primary endpoint.