View clinical trials related to Tenofovir.
Filter by:Although several therapeutic agents have been suggested for the treatment of the disease caused by the Coronavirus of the year 2019 (COVID-19), no antiviral has yet demonstrated consistent efficacy. This is an observational study comparing Tenofovir-DF (disoproxil fumarate) (TDF) with Hydroxychloroquine (HCQ) in the treatment of hospitalized patients with COVID-19 with evidence of pulmonary compromise and with supplemental oxygen required.
Tenofovir is a nucleotide analog drug that works against both Human immunodeficiency virus (HIV) and HBV. TDF and TAF are prodrug of Tenofovir. TAF has a higher plasma stability than TDF, which makes TDF require a higher dose to get the concentration of drugs in the liver equal to the amount of TAF. Previous studies have shown the effects of TAF once daily and TDF once daily on kidney function and bone mass. The efficacy of TAF in virus suppression is comparable to TDF, but the effect on the kidneys and bone mass from TAF has less side effects than TDF. In addition, changing the medication from TDF to TAF shows that kidney function tends to improve. Hepatitis B patients taking TDF have adjusted their dosage due to impair renal function, for example, from 1 time per day to every 48 hours or every 72 hours. This group of patients does not have a clear evidence-based recommendation for choosing a reduced dose of TDF or change to TAF. Therefore, the main objective of this study is to study patients with hepatitis B who have taken TDF and have renal function impairment that have been adjusted. Taking the same medicine with dose adjustment or changing the drug to TAF which treatment will more improve the kidney function.
Hepatitis B virus (HBV) can be asymptomatic for years but can also lead to chronic hepatitis, hepatocellular carcinoma, and liver failure and death and cannot be eradicated with the current therapy. Chronic maternal HBV infection is an important source of perinatal transmission in regions of high HBV prevalence. In antenatal clinics at Shoklo Malaria Research Unit (SMRU), the Hepatitis B (HB) surface antigen (sAg) prevalence is 8.3% with a HB e-antigen (HBeAg) prevalence of 32.7% in those positive for HBsAg in 2012-2014. Perinatal infection occurs in 70-90% of women with HBeAg positive chronic HBV compared with 0-30% in those with HBeAg negative chronic HBV (inactive carriers). These infection rates reflect, in part, the failure of maternal and child health programs to prevent perinatal transmission with hepatitis B immunoglobulin (HBIG) and HB vaccines. Prevention of mother to child transmission (PMTCT) fails in an estimated 8-32% of cases with adequate preventive techniques. Antiretrovirals, like tenofovir (TFV) that is administered as the prodrug Tenofovir Disoproxil Fumarate (TDF), are active against HBV and may reduce the risk of HBV transmission at birth if offered at the right time in pregnancy. One of the major gaps in implementing this strategy is adequate pharmacokinetic (PK) data in pregnant women that informs correct dosing. One recently published population PK study in 154 women who provided maternal blood samples (32 and 36 weeks of pregnancy, at delivery, and at 1 and 2 months post-partum) reported a tenofovir area under curve (AUC) 0-24 that was estimated to be 20% (95% CI, 19-21%) lower during pregnancy than during post-partum suggesting no dose adjustments are needed in 3rd trimester. Most PK studies for TDF in pregnancy have been for Human Immunodeficiency Virus type 1 (HIV-1) infections. However, these patients often receive additional antiretroviral medications, preventing conclusions on PK parameters of Tenofovir (TFV) alone. Doses that are optimal for HIV may not be appropriate for HBV. When TDF is administered during pregnancy and potentially during lactation, it is important to establish the infant drug exposure. Previous human studies have shown that antiretrovirals administered to lactating mothers are present in the breast milk and have detected a low TDF breast milk concentration representing 0.03% or less of the proposed infant dosage. However, there is no data on this subject in therapeutic treatment of HBV infected women. In resource poor settings TDF administration will be ceased after 1 month post-partum. While there is some understanding of what happens to viral load post cessation in non-pregnant individuals, post-partum TDF cessation is less well understood and may be affected by differences in immunity. With breastmilk as the primary source of nutrition for babies in resource limited settings, it is important to know the viral exposure from breastmilk, if any, as these settings may also have problems achieving birth dose, HBIG and completion of the recommended three doses of vaccine. The investigators propose a dense PK study of once daily TDF 300 mg during pregnancy given for PMTCT of HBV mono-infection. Tenofovir PK will be measured in maternal blood samples in steady-state, in the 2nd and 3rd trimesters and post-partum. The presence of HBV DNA in blood and breast milk will also be explored in women after cessation of treatment until 6 months post-partum.