A simple, rapid and sensitive method was developed for the quantification of tenofovir in plasma of Beagle dogs using HPLC-MS/MS analysis. The analytes tenofovir and internal standard (IS) adefovir were separated on a Zorbax SB-C18 column (3.5 microm, 100 mm x 2.1 mm, Agilent, USA) with mobile phase of methanol/water containing 0.3% formic acid using a gradient elution mode at a flow rate of 0.2 mL x min(-1). The plasma sample preparation was a simple deproteinization by the addition of 20% trichloroacetic acid followed by centrifugation. The detection was performed in positive selected reaction monitoring (SRM) mode with an electrospray ionization (ESI) source. The reactions monitored were m/z 288.1-176.2 for tenofovir and m/z 274.1-162.2 for adefovir (IS). Linear detection responses were obtained for tenofovir ranging from 10 to 5 000 ng x mL(-1). The intra- and inter-day precisions (RSD%) was no more than 6.3% with high recovery and good stability for the quantification, indicating the present method was specific, fast, accurate and reliable. The method was successfully applied to the pharmacokinetic study of two tenofovir agents. Tenofovir dipivoxil fumarate (BP0018, test agent) and tenofovir disoproxil fumarate (reference agent) were orally administrated to 8 Beagle dogs according to the 2 x 2 crossover design. Comparing with the reference agent, the longer MRT and t1/2 were obtained in the group of BP0018, while no significant difference was observed in AUC(0-t), AUC(0-infinity), C(max) and t(max) between them, suggesting that tenofovir dipivoxil fumarate was bioequivalent to the tenofovir disoproxil fumarate in Beagle dogs.
Adenine ; administration & dosage ; analogs & derivatives ; blood ; pharmacokinetics ; Administration, Oral ; Animals ; Area Under Curve ; Chromatography, High Pressure Liquid ; Dogs ; Female ; Male ; Organophosphonates ; administration & dosage ; blood ; pharmacokinetics ; Phosphorous Acids ; administration & dosage ; pharmacokinetics ; Reverse Transcriptase Inhibitors ; blood ; Tandem Mass Spectrometry ; Tenofovir

BACKGROUNDTo assess the safety and tolerance of adefovir dipivoxil tablet in Chinese healthy volunteers.

METHODSTotally 42 healthy volunteers were enrolled in the study, 21 were female and 21 were male and their age ranged from 19 to 26 years. The subjects were randomly divided into 5, 10, 20, 40 and 60 mg dose-groups (6-10 subjects in each group) based on sex and weight, beginning with the 5 mg dose-group. Clinical symptoms, vital signs, electrocardiogram, routine blood test, routine urine test, prothrombin time and blood biochemical tests were recorded and evaluated.

RESULTSNo significant changes were found in clinical symptoms, vital signs and laboratory tests after dosing, except slight elevations of alanine aminotransferase in 2 subjects and bilirubin in 6 subjects observed and some gastrointestinal symptoms such as nausea and diarrhea found in 3 subjects, but the frequency and severity of all the adverse reactions were not found to be related to the dosages.

CONCLUSIONThe results showed that single oral dose of adefovir dipivoxil 60 mg or less was safe and tolerable.

Adenine ; administration & dosage ; adverse effects ; analogs & derivatives ; Administration, Oral ; Adult ; Antiviral Agents ; administration & dosage ; adverse effects ; Diarrhea ; chemically induced ; Dose-Response Relationship, Drug ; Female ; Humans ; Male ; Nausea ; chemically induced ; Organophosphonates ; administration & dosage ; adverse effects ; Tablets ; Young Adult

To investigate the efficacy of 104 weeks of lamivudine (LAM) and adefovir (ADV) de novo combination therapy, as compared to optimized combination therapy administered after 48 weeks of treatment with lamivudine or adefovir mono-therapy, in chronic hepatitis B (CHB) patients. A total of 174 patients with CHB were equally divided among three treatment groups: LAM mono-therapy; ADV mono-therapy; and LAM + ADV combination therapy. The patients in the LAM + ADV group were treated with LAM plus ADV for 104 consecutive weeks. The patients in the LAM or the ADV groups were first treated for 48 weeks with LAM or ADV, respectively, after which the patient's virological response was assessed. According to the results, the patient was continued on mono-therapy or switched to combination therapy for the subsequent 56 weeks. Virological and biochemical examinations were carried out at weeks 48 and 104. The rates of undetectable HBV DNA in the LAM mono-therapy, ADV mono-therapy, and LAM-ADV combination therapy groups at week 48 were 68%, 50%, and 84%, and at week 104 were 80%, 72%, and 95%, respectively. For the same groups, the virus breakthrough rates at week 48 were 15%, 0%, and 0%, and at week 104 were 18%, 2%, and 0%, respectively. Statistical analysis showed significant differences for the rate of undetectable HBV DNA between LAM + ADV group and LAM group at week 48 (x2 = 4.473, P= 0.034) and at week 104 (x2 = 5.795, P = 0.016), LAM + ADV group and ADM group at week 48 (x2 = 14.802, P less than 0.001) and week 104 (x2 = 5.547, P = 0.001). The hepatitis B e antigen (HBeAg) seroconversion rates at week 48 were 15% (x2 = 4.543, P = 0.033), 13% (x2 = 4.035, P = 0.045) and 38%, and at week 104 were 21% (x2 = 4.438, P = 0.035), 17% (x2 = 4.223, P = 0.04) and 44%, respectively, among patients positive for HBeAg. Statistical analysis showed that the differences among the three groups for each of these parameters were statistically significant (all, P less than 0.05). When compared with LAM or ADV mono-therapy followed by LAM+ADV at week 48, the LAM plus ADV de novo combination therapy for 104 weeks provided CHB patients with better virological and serological responses and a lower drug resistance rate.
Adenine ; administration & dosage ; analogs & derivatives ; therapeutic use ; Adult ; Drug Therapy, Combination ; Female ; Hepatitis B, Chronic ; drug therapy ; Humans ; Lamivudine ; administration & dosage ; therapeutic use ; Male ; Middle Aged ; Organophosphonates ; administration & dosage ; therapeutic use ; Prospective Studies ; Treatment Outcome

Herein, solid lipid nanoparticles (SLN) were proposed as a new drug delivery system for adefovir dipivoxil (ADV). The octadecylamine-fluorescein isothiocynate (ODA-FITC) was synthesized and used as a fluorescence maker to be incorporated into SLN to investigate the time-dependent cellular uptake of SLN by HepG2.2.15. The SLN of monostearin with ODA-FITC or ADV were prepared by solvent diffusion method in an aqueous system. About 15 wt% drug entrapment efficiency (EE) and 3 wt% drug loading (DL) could be reached in SLN loading ADV. Comparing with free ADV, the inhibitory effects of ADV loaded in SLN on hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg) and hepatitis B virus (HBV) DNA levels in vitro were significantly enhanced.
Adenine ; administration & dosage ; analogs & derivatives ; pharmacokinetics ; Amines ; Antiviral Agents ; administration & dosage ; pharmacokinetics ; Cell Line ; Drug Delivery Systems ; Fluorescein-5-isothiocyanate ; Fluorescent Dyes ; Glycerides ; Hepatitis B virus ; drug effects ; Humans ; Nanoparticles ; Nanotechnology ; Organophosphonates ; administration & dosage ; pharmacokinetics

Adenine ; administration & dosage ; analogs & derivatives ; therapeutic use ; Animals ; Antiviral Agents ; therapeutic use ; Drug Therapy, Combination ; Genetic Therapy ; Hepatitis B, Chronic ; drug therapy ; virology ; Humans ; Interferon-alpha ; administration & dosage ; therapeutic use ; Lamivudine ; therapeutic use ; Organophosphonates ; administration & dosage ; therapeutic use ; Phytotherapy

To evaluate the efficacy and safety of pegylated-interferon (Peg-IFN) treatment as monotherapy or in combination with nucleoside analogues (NAs) for treating chronic hepatis B (CHB) infection.Searches of PubMed, OVID, EMBASE, and the Chinese Medical (WanFang, CNKI, and VIP) databases were conducted to identify all relevant randomized controlled trials published since January 1990. Twelve studies comparing Peg-IFN monotherapy to NA combination therapy (lamivudine (LAM), n =8); adefovir (ADV), n = 4) met the inclusion criteria (treatment duration, range: 48-52 weeks; follow-up, range: 24 weeks to three years). Meta-analysis was performed with RevMan 5.0 using the fixed-effects and random-effects models. Patients who had received combination therapy had a higher biochemical response rate at the end of treatment than those who had received monotherapy (51.1% vs. 38.9%, odds ratio (OR) = 1.63, 95% confidence interval (CI): 1.33-2.01, P less than 0.01). Subgroup analysis of Peg-IFN combination therapies with LAM or ADV indicated that neither NA type significantly enhanced the increased efficacy of combination therapy compared to monotherapy. The combination therapy subgroups also had higher virologic response rates at the end of treatment than the monotherapy subgroups (LAM: 65.9% vs. 34.9%, OR = 3.57, 95% CI: 1.83-6.95, P less than 0.01; ADV: 74.6% vs. 46.2%, OR = 3.66, 95% CI: 2.13-6.30, P less than 0.01). Moreover, the combination therapy group had a higher sustained biochemical response rate at the end of follow-up than the monotherapy group (47.6% vs. 42.1%, OR = 1.28, 95% CI: 1.05-1.55, P less than 0.05). The LAM combination therapy subgroup had a significantly higher biochemical response rate than the monotherapy subgroup, but there was no significant difference between the LAM and ADV combination therapy subgroups. At the end of follow-up, the ADV combination therapy subgroup had a significantly lower rate of hepatitis B e antigen (HBeAg) than the monotherapy subgroup, but there was no significant difference between the ADV and LAM combination therapy subgroups for HbeAg reduction. The combination therapy group and monotherapy group showed no statistically significant differences in HBsAg reduction or occurrence of severe adverse events. Peg-IFN/NA combination therapy produces a higher biochemical response rate in CHB patients than PEG-IFN monotherapy. Moreover, Peg-IFN/ADV combination therapy produces a greater reduction in HBeAg than Peg-IFN monotherapy.
Adenine ; administration & dosage ; analogs & derivatives ; Antiviral Agents ; administration & dosage ; adverse effects ; therapeutic use ; Drug Therapy, Combination ; Hepatitis B, Chronic ; drug therapy ; Humans ; Interferons ; administration & dosage ; adverse effects ; therapeutic use ; Lamivudine ; administration & dosage ; Nucleosides ; administration & dosage ; adverse effects ; therapeutic use ; Organophosphonates ; administration & dosage ; Polyethylene Glycols ; administration & dosage ; adverse effects ; therapeutic use ; Randomized Controlled Trials as Topic ; Treatment Outcome

OBJECTIVETo investigate the efficacy and safety of an extended course (96-week) of combination treatment with peginterferon alfa-2a (Peg-IFNa-2a; 40 kd] plus adefovir (ADV) for treating chronic hepatitis B (CHB) in Chinese patients with negativity for hepatitis B e antigen (HBeAg).

METHODSA total of 25 consecutive patients with HBeAg-negative CHB were administered Peg-IFNa-2a (135-180 mug/week) plus ADV (10 mg/day) for 96 weeks. All patients were followed-up for 24 weeks after treatment completion. Levels of hepatitis B virus (HBV) DNA and hepatitis B surface antigen (HbsAg) were measured by fluorescence quantitative polymerase chain reaction (FQ-PCR) and chemiluminescent microparticle immunoassay, respectively, at 12-week intervals throughout the treatment course and at the end-of-follow-up (week 120). Patients underwent serological analysis at 3-6 month intervals during treatment and follow-up to evaluate occurrence of adverse events; serological parameters included blood count, markers of liver, kidney and thyroid function, and levels of autoantibodies and creatine kinase.

RESULTSFor all patients, the 96-week course of Peg-IFNa-2a plus ADV reduced the level of HBV DNA below the detection threshold (less than 500 copies/ml by FQ-PCR). The overall rate of HBsAg seroconversion was 12% (3/25) at week 48, 28% (7/25) at week 96, and 32% (8/25) at week 120. The occurrences of adverse events were similar at week 48 and week 96.

CONCLUSIONThe extended-course Peg-IFNa-2a plus ADV combination therapy achieved a 100% virological response and better rates of HBsAg seroconversion than 48 weeks of therapy, without a decrease in safety.

Adenine ; administration & dosage ; analogs & derivatives ; therapeutic use ; Adult ; Antiviral Agents ; administration & dosage ; therapeutic use ; Drug Therapy, Combination ; Female ; Hepatitis B e Antigens ; Hepatitis B, Chronic ; drug therapy ; Humans ; Interferon-alpha ; administration & dosage ; therapeutic use ; Male ; Middle Aged ; Organophosphonates ; administration & dosage ; therapeutic use ; Polyethylene Glycols ; administration & dosage ; therapeutic use ; Recombinant Proteins ; administration & dosage ; therapeutic use ; Treatment Outcome

Currently available monotherapies of oral nucleoside/nucleotide analogs or interferon are unable to achieve a sustained and effective response in most of patients with chronic hepatitis B (CHB). The objective of the present study was to compare the efficacy and safety of pegylated interferon (Peg-IFN) alpha-2b plus adefovir dipivoxil combination therapy versus Peg-IFN alpha-2b alone. Sixty-one HBeAg-positive chronic hepatitis B patients were randomized to receive Peg-IFN alpha-2b alone (1.5 μg/kg once weekly) or Peg-IFN alpha-2b plus adefovir (10 mg daily) for up to 52 weeks. Efficacy and safety analyses were performed on all participants who received at least one dose of study medication. The rate of HBeAg seroconversion and undetectable HBV-DNA were evaluated after 52 weeks of therapy. At the end of treatment, 11 of 30 (36.7%) patients receiving combination therapy achieved HBeAg seroconversion versus 8 of 31 (25.8%) in the monotherapy group (P=0.36). In contrast, the percentage of patients with undetectable serum HBV DNA was significantly higher in the combination group than in the monotherapy group (76.7% vs. 29.0%, P<0.001). Thyroid dysfunction was more frequent in the combination group than in the monotherapy group (P<0.05). In HBeAg-positive CHB, combination of Peg-IFN alpha-2b and adefovir for 52 weeks resulted, at the end of treatment, in a higher virological response but without significant impact on the rate of HBeAg seroconversion and possibly an adverse effect on thyroid function.
Adenine ; administration & dosage ; adverse effects ; analogs & derivatives ; Adolescent ; Adult ; Antiviral Agents ; administration & dosage ; adverse effects ; Drug Therapy, Combination ; Female ; Hepatitis B e Antigens ; blood ; Hepatitis B, Chronic ; blood ; drug therapy ; Humans ; Interferon-alpha ; administration & dosage ; adverse effects ; Male ; Organophosphonates ; administration & dosage ; adverse effects ; Polyethylene Glycols ; administration & dosage ; adverse effects ; Prospective Studies ; Recombinant Proteins ; administration & dosage ; adverse effects

OBJECTIVETo study the changes of experimental markers of hepatic fibrosis in patients with chronic hepatitis B treated by Dahuang Zhechong Wan combined with adefovir dipivoxil.

METHODNinty and four cases of chronic viral hepatitis B patients were randomly divided into two groups. The treatment group (50 cases) was orally given 10 mg of adefovir dipivoxil once a day, 1 Wan each time, combined with Dahuang Zhechong Wan, 3 times a day, 1 Wan each time. And the control group (44 cases) was treated with adefovir dipivoxil alone, 6 months as a course.

RESULTBoth the difference of liver fibrosis indexes between the treatment group and the control group and before and after the treatment in the treatment group had statistical significance (P < 0.01 or P < 0.05). Both the difference of experimental markers such as ALT, AST, GGT, TBIL between the treatment group and the control group and before and after the treatment in the treatment group had statistical significance (P < 0.01).

CONCLUSIONDahuang Zhechong Wan combined with adefovir dipivoxil could prevent hepatic fibrosis in patients with chronic hepatitis B, reduce the incidence of liver cirrhosis, improve life quality and prognosis.

Adenine ; administration & dosage ; analogs & derivatives ; Administration, Oral ; Adult ; Aged ; Antiviral Agents ; administration & dosage ; Biomarkers ; analysis ; Drug Therapy, Combination ; Drugs, Chinese Herbal ; administration & dosage ; Female ; Hepatitis B, Chronic ; complications ; drug therapy ; Humans ; Liver ; metabolism ; Liver Cirrhosis ; prevention & control ; virology ; Male ; Middle Aged ; Organophosphonates ; administration & dosage ; Young Adult

OBJECTIVETo evaluate the efficacy of entecavir (ETV) 1.0 mg/d or ETV plus adefovir dipivoxil (ADV) in adults with chronic hepatitis B virus (HBV) infection who had previously resisted lamivudine (LAM) and failed with rescue treatment of LAM + ADV.

METHODS40 patients were enrolled. 14 patients were treated with ETV 1.0 mg/d monotherapy while 26 patients were treated with ETV 1.0 mg/d + ADV 10 mg/d. The HBV DNA level, liver function, HBV serology and renal function were observed.

RESULTSThere was no statistically significant difference with baseline situation between group ETV 1.0 mg and group ETV + ADV. HBV DNA level in group ETV 1.0 mg was (5.768 ± 0.709) log10 copies/ml on baseline, and it declined to (4.712 ± 0.846) log10 copies/ml, (3.914 ± 0.996) log10 copies/ml, (3.702 ± 0.934) log10 copies/ml, (3.879 ± 0.913) log10 copies/ml and (3.855 ± 1.070) log10 copies/ml at 4, 8, 12, 24 and 48 weeks. HBV DNA level in group ETV + ADV was (5.703 ± 0.845) log10 copies/ml on baseline, and it declined to (4.476 ± 0.905) log10 copies/ml, (3.590 ± 0.884) log10 copies/ml, (2.987 ± 0.673) log10 copies/ml and (2.933 ± 0.535) log10 copies/ml at 4, 8, 12 and 24 weeks. At 24 weeks, there were 28.6% patients achieved HBV DNA < 500 copies/ml in group ETV 1.0 mg, but there were 80.8% patients in group ETV + ADV achieved this level. Statistically significant difference existed between (x(2) = 8.469, P = 0.004 ). At 48 weeks, there were still 4 patients achieved HBV DNA < 500 copies/ml in group ETV 1.0 mg, but patients in group ETV + ADV all achieved it. At 24 weeks, ALT levels of 42.9% patients in group ETV 1.0 mg were back to normal, but there were 92.3% patients' ALT levels back to normal in group ETV + ADV. There was statistically significant difference (x(2) = 9.337, P = 0.002). At 48 weeks, ALT levels of 57.1% patients in group ETV 1.0 mg were back to normal, but all patients' ALT levels were back to normal in group ETV + ADV. At 48 weeks, there was 1 patient with HBeAg seroconversion in group ETV 1.0 mg while there were 4 patients in group ETV + ADV.

CONCLUSIONAs rescue treatment for patients with chronic hepatitis B who had previously resisted LAM and failed with treatment of LAM + ADV, ETV + ADV was more efficient than ETV 1.0 mg monotherapy, and it can achieve better virological and biochemical response.

Adenine ; administration & dosage ; analogs & derivatives ; therapeutic use ; Adult ; Antiviral Agents ; administration & dosage ; therapeutic use ; Drug Resistance, Viral ; Drug Therapy, Combination ; Female ; Guanine ; administration & dosage ; analogs & derivatives ; therapeutic use ; Hepatitis B, Chronic ; drug therapy ; Humans ; Lamivudine ; therapeutic use ; Male ; Middle Aged ; Organophosphonates ; administration & dosage ; therapeutic use ; Treatment Outcome