scholarly journals Single-Dose and Steady-State Pharmacokinetics of Tenofovir Disoproxil Fumarate in Human Immunodeficiency Virus-Infected Children

2004 ◽  
Vol 48 (1) ◽  
pp. 124-129 ◽  
Author(s):  
Rohan Hazra ◽  
Frank M. Balis ◽  
Antonella N. Tullio ◽  
Ellen DeCarlo ◽  
Carol J. Worrell ◽  
...  

ABSTRACT Tenofovir disoproxil fumarate (DF) is a potent nucleotide analog reverse transcriptase inhibitor approved for the treatment of human immunodeficiency virus (HIV)-infected adults. The single-dose and steady-state pharmacokinetics of tenofovir were evaluated following administration of tenofovir DF in treatment-experienced HIV-infected children requiring a change in antiretroviral therapy. Using increments of tenofovir DF 75-mg tablets, the target dose was 175 mg/m2; the median administered dose was 208 mg/m2. Single-dose pharmacokinetics were evaluated in 18 subjects, and the geometric mean area under the concentration-time curve from 0 h to ∞ (AUC0-∞) was 2,150 ng · h/ml and the geometric mean maximum concentration (C max) was 266 ng/ml. Subsequently, other antiretrovirals were added to each patient's regimen based upon treatment history and baseline viral resistance results. Steady-state pharmacokinetics were evaluated in 16 subjects at week 4. The steady-state, geometric mean AUC for the 24-h dosing interval was 2,920 ng · h/ml and was significantly higher than the AUC0-∞ after the first dose (P = 0.0004). The geometric mean C max at steady state was 302 ng/ml. Tenofovir DF was generally very well tolerated. Steady-state tenofovir exposures in children receiving tenofovir DF-containing combination antiretroviral therapy approached values seen in HIV-infected adults (AUC, ∼3,000 ng · h/ml; C max, ∼300 ng/ml) treated with tenofovir DF at 300 mg.

2011 ◽  
Vol 55 (7) ◽  
pp. 3613-3615 ◽  
Author(s):  
Lauriane Goldwirt ◽  
Joséphine Braun ◽  
Nathalie de Castro ◽  
Isabelle Charreau ◽  
Aurélie Barrail-Tran ◽  
...  

ABSTRACTWe compared tipranavir and darunavir concentrations measured at steady state in 20 human immunodeficiency virus (HIV)-infected patients enrolled in the EASIER-ANRS 138 clinical trial who switched from enfuvirtide to raltegravir while maintaining the same background regimen. The geometric mean ratios of the observed predose concentration (Ctrough), maximum concentration of drug observed in plasma (Cmax), and area under the plasma concentration-time curve (AUC) before (day 0) and after (week 24) the switch were 0.49, 0.76, and 0.67 and 0.82, 0.68, and 0.64 for tipranavir and darunavir, respectively. The virologic consequences of these drug interactions have yet to be determined.


2004 ◽  
Vol 48 (6) ◽  
pp. 2091-2096 ◽  
Author(s):  
Anne-Marie Taburet ◽  
Christophe Piketty ◽  
Corine Chazallon ◽  
Isabelle Vincent ◽  
Laurence Gérard ◽  
...  

ABSTRACT The aim of the present study was to assess the pharmacokinetic behavior of atazanavir-ritonavir when it is coadministered with tenofovir disoproxil fumarate (DF) in human immunodeficiency virus (HIV)-infected patients. Eleven patients enrolled in Agence Nationale de Recherche sur le SIDA (National Agency for AIDS Research, Paris, France) trial 107 were included in this pharmacokinetic study. They received atazanavir at 300 mg and ritonavir at 100 mg once a day (QD) from day 1 to the end of study. For the first 2 weeks, their nucleoside analog reverse transcriptase inhibitor (NRTI) treatments remained unchanged. Tenofovir DF was administered QD from day 15 to the end of the study. Ongoing NRTIs were selected according to the reverse transcriptase genotype of the HIV isolates from each patient. The values of the pharmacokinetic parameters for atazanavir and ritonavir were measured before (day 14 [week 2]) and after (day 42 [week 6]) initiation of tenofovir DF and are reported for the 10 patients who completed the study. There was a significant decrease in the area under the concentration-time curve from 0 to 24 h (AUC0-24) for atazanavir with the addition of tenofovir DF (AUC0-24 ratio, 0.75; 90% confidence interval, 0.58 to 0.97; P = 0.05). There was a trend for a decrease in the minimum concentrations of atazanavir and ritonavir in plasma when they were combined with tenofovir, but none of the differences reached statistical significance. The median decreases in the HIV RNA loads at week 2 and week 6 were 0.1 and 0.2 log copies/ml, respectively. In summary, our data are consistent with the existence of a significant interaction between atazanavir and tenofovir DF.


2016 ◽  
Vol 3 (3) ◽  
Author(s):  
Sean E. Collins ◽  
Philip M. Grant ◽  
Francois Uwinkindi ◽  
Annie Talbot ◽  
Eric Seruyange ◽  
...  

Abstract Background.  Many human immunodeficiency virus (HIV)-infected patients remain on nevirapine-based antiretroviral therapy (ART) despite safety and efficacy concerns. Switching to a rilpivirine-based regimen is an alternative, but there is little experience with rilpivirine in sub-Saharan Africa where induction of rilpivirine metabolism by nevirapine, HIV subtype, and dietary differences could potentially impact efficacy. Methods.  We conducted an open-label noninferiority study of virologically suppressed (HIV-1 ribonucleic acid [RNA] < 50 copies/mL) HIV-1-infected Rwandan adults taking nevirapine plus 2 nucleos(t)ide reverse-transcriptase inhibitors. One hundred fifty participants were randomized 2:1 to switch to coformulated rilpivirine-emtricitabine-tenofovir disoproxil fumarate (referenced as the Switch Arm) or continue current therapy. The primary efficacy endpoint was HIV-1 RNA < 200 copies/mL at week 24 assessed by the US Food and Drug Administration Snapshot algorithm with a noninferiority margin of 12%. Results.  Between April and September 2014, 184 patients were screened, and 150 patients were enrolled; 99 patients switched to rilpivirine-emtricitabine-tenofovir, and 51 patients continued their nevirapine-based ART. The mean age was 42 years and 43% of participants were women. At week 24, virologic suppression (HIV-1 RNA level <200 copies/mL) was maintained in 93% and 92% in the Switch Arm versus the continuation arm, respectively. The Switch Arm was noninferior to continued nevirapine-based ART (efficacy difference 0.8%; 95% confidence interval, −7.5% to +12.0%). Both regimens were generally safe and well tolerated, although 2 deaths, neither attributed to study medications, occurred in participants in the Switch Arm. Conclusions.  A switch from nevirapine-based ART to rilpivirine-emtricitabine-tenofovir disoproxil fumarate had similar virologic efficacy to continued nevirapine-based ART after 24 weeks with few adverse events.


2004 ◽  
Vol 48 (11) ◽  
pp. 4328-4331 ◽  
Author(s):  
Robert DiCenzo ◽  
Derick Peterson ◽  
Kim Cruttenden ◽  
Gene Morse ◽  
Garret Riggs ◽  
...  

ABSTRACT Valproic acid (VPA) has the potential to benefit patients suffering from human immunodeficiency virus (HIV)-associated cognitive impairment. The purpose of this study was to determine if VPA affects the plasma concentration of efavirenz (EFV) or lopinavir. HIV type 1 (HIV-1)-infected patients receiving EFV or lopinavir-ritonavir (LPV/r) had 9 or 10 blood samples drawn over 8 to 24 h of a dosing interval at steady state before and after receiving 250 mg of VPA twice daily for 7 days. VPA blood samples drawn before (C 0) and 8 h after the morning dose (8 h) were compared to blood samples from a group of HIV-1-infected subjects who were taking either combined nucleoside reverse transcriptase inhibitors alone or had discontinued antiretroviral therapy. Pharmacokinetic parameters were calculated by noncompartmental analysis, and tests of bioequivalence were based on 90% confidence intervals (CIs) for ratios or differences. The geometric mean ratio (GMR) (90% CI) of the areas under the concentration-time curve from 0 to 24 h (AUC0-24s) of EFV (n = 11) with and without VPA was 1.00 (0.85, 1.17). The GMR (90% CI) of the AUC0-8s of LPV (n = 8) with and without VPA was 1.38 (0.98, 1.94). The differences (90% CI) in mean C 0 and 8-h VPA concentrations versus the control (n = 11) were −1.0 (−9.4, 7.4) μg/ml and −2.1 (−11.1, 6.9) μg/ml for EFV (n = 10) and −5.0 (−13.2, 3.3) μg/ml and −6.7 (−17.6, 4.2) μg/ml for LPV/r (n = 11), respectively. EFV administration alone is bioequivalent to EFV and VPA coadministration. LPV concentrations tended to be higher when the drug was combined with VPA. Results of VPA comparisons fail to raise concern that coadministration with EFV or LPV/r will significantly influence trough concentrations of VPA.


2003 ◽  
Vol 47 (1) ◽  
pp. 118-123 ◽  
Author(s):  
Cecile Goujard ◽  
Isabelle Vincent ◽  
Jean-Luc Meynard ◽  
Nathalie Choudet ◽  
Diane Bollens ◽  
...  

ABSTRACT The protease inhibitor (PI) ritonavir is used as a strong inhibitor of cytochrome P450 3A4, which boosts the activities of coadministered PIs, resulting in augmented plasma PI levels, simplification of the dosage regimen, and better efficacy against resistant viruses. The objectives of the present open-label, multiple-dose study were to determine the steady-state pharmacokinetics of amprenavir administered at 600 mg twice daily (BID) and ritonavir administered at 100 mg BID in human immunodeficiency virus type 1 (HIV-1)-infected adults treated with different antiretroviral combinations including or not including a nonnucleoside reverse transcriptase inhibitor (NNRTI). Nineteen patients completed the study. The steady-state mean minimum plasma amprenavir concentration (C min,ss) was 1.92 μg/ml for patients who received amprenavir and ritonavir without an NNRTI and 1.36 μg/ml for patients who received amprenavir and ritonavir plus efavirenz. For patients who received amprenavir-ritonavir without an NNRTI, the steady-state mean peak plasma amprenavir concentration (C max,ss) was 7.12 μg/ml, the area under the concentration-time curve from 0 to 10 h (AUC0-10) was 32.06 μg · h/ml, and the area under the concentration-time curve over a dosing interval (12 h) at steady-state (AUCss) was 35.74 μg · h/ml. Decreases in the mean values of C min,ss (29%), C max,ss (42%), AUC0-10 (42%), and AUCss (40%) for amprenavir occurred when efavirenz was coadministered with amprenavir-ritonavir. No unexpected side effects were observed. As expected, coadministration of amprenavir with ritonavir resulted in an amprenavir C min,ss markedly higher than those previously reported for the marketed dose of amprenavir. When amprenavir-ritonavir was coadministered with efavirenz, amprenavir-ritonavir maintained a mean amprenavir C min,ss above the mean 50% inhibitory concentration of amprenavir previously determined for both wild-type HIV-1 isolates and HIV-1 strains isolated from PI-experienced patients. These data support the use of low-dose ritonavir to enhance the level of exposure to amprenavir and increase the efficacy of amprenavir.


2004 ◽  
Vol 48 (1) ◽  
pp. 183-191 ◽  
Author(s):  
Laurene H. Wang ◽  
Andrew A. Wiznia ◽  
Mobeen H. Rathore ◽  
Gregory E. Chittick ◽  
Saroj S. Bakshi ◽  
...  

ABSTRACT Emtricitabine (FTC; Emtriva), a potent deoxycytidine nucleoside reverse transcriptase inhibitor, has recently been approved by the U.S. Food and Drug Administration for the treatment of human immunodeficiency virus (HIV) infection. In adults, FTC has demonstrated linear kinetics over a wide dose range, and FTC 200 mg once a day (QD) is the recommended therapeutic dose. A phase I open-label trial was conducted in children to identify an FTC dosing regimen that would provide comparable plasma exposure to that observed in adults at 200 mg QD. Two single oral doses of FTC (60 and 120 mg/m2, up to a maximum of 200 mg, in solutions) were evaluated in HIV-infected children aged <18 years old. Children ≥6 years old also received a third dose of ∼120 mg/m2 in capsules. A total of 25 children (two <2 years old, eight 2 to 5 years old, eight 6 to 12 years old, and seven 13 to 17 years old) received at least two doses of FTC. Single escalating oral doses of FTC were well tolerated and produced dose-proportional plasma drug concentrations in children. The FTC pharmacokinetics was comparable between adults and children 22 months to 17 years of age. The capsule formulation provided ∼20% higher plasma FTC exposure than the solution formulation. Using plasma area under the concentration-time curve (AUC) data at the 120-mg/m2 dose, it is projected (based on dose proportionality) that a 6-mg/kg dose (up to a maximum of 200 mg) of FTC would produce plasma AUCs in children comparable to those in adults given a 200-mg dose (i.e., median of ∼10 h·μg/ml). This pediatric FTC dose is being evaluated in long-term phase II therapeutic trials in HIV-infected children.


2006 ◽  
Vol 50 (7) ◽  
pp. 2309-2315 ◽  
Author(s):  
Xiao-Jian Zhou ◽  
Barbara A. Fielman ◽  
Deborah M. Lloyd ◽  
George C. Chao ◽  
Nathaniel A. Brown

ABSTRACT Two phase I studies were conducted to assess the plasma pharmacokinetics of telbivudine and potential drug-drug interactions between telbivudine (200 or 600 mg/day) and lamivudine (100 mg/day) or adefovir dipivoxil (10 mg/day) in healthy subjects. Study drugs were administered orally. The pharmacokinetics of telbivudine were characterized by rapid absorption with biphasic disposition. The maximum concentrations in plasma (C max) were reached at median times ranging from 2.5 to 3.0 h after dosing. Mean single-dose C max and area under the plasma concentration-time curve from time zero to infinity (AUC0-∞) were 1.1 and 2.9 μg/ml and 7.4 and 21.8 μg · h/ml for the 200- and 600-mg telbivudine doses, respectively. Steady state was reached after daily dosing for 5 to 7 days. The mean steady-state C max and area under the plasma concentration-time curve over the dosing interval (AUCτ) were 1.2 and 3.4 μg/ml and 8.9 and 27.5 μg · h/ml for the 200- and 600-mg telbivudine repeat doses, respectively. The steady-state AUCτ of telbivudine was 23 to 57% higher than the single-dose values. Concomitant lamivudine or adefovir dipivoxil did not appear to significantly alter the steady-state plasma pharmacokinetics of telbivudine; the geometric mean ratios and associated 90% confidence interval (CI) for the AUCτ of telbivudine alone versus in combination were 106.3% (92.0 to 122.8%) and 98.6% (86.4 to 112.5%) when coadministered with lamivudine and adefovir dipivoxil, respectively. Similarly, the steady-state plasma pharmacokinetics of lamivudine or adefovir were not markedly affected by the coadministration of telbivudine; the geometric mean ratios and associated 90% CI, alone versus in combination with telbivudine, were 99.0% (87.1 to 112.4%) and 92.2% (84.0 to 101.1%), respectively, for the lamivudine and adefovir AUCτ values. Moreover, the combination regimens studied were well tolerated in all subjects. The results from these studies provide pharmacologic support for combination therapy or therapy switching involving telbivudine, lamivudine, and adefovir dipivoxil for the treatment of chronic hepatitis B virus infection.


2004 ◽  
Vol 48 (5) ◽  
pp. 1904-1907 ◽  
Author(s):  
A. S. Bergshoeff ◽  
P. L. A. Fraaij ◽  
A. M. C. van Rossum ◽  
G. Verweel ◽  
L. H. Wynne ◽  
...  

ABSTRACT So far, no pediatric doses for indinavir combined with ritonavir have been defined. This study evaluated the pharmacokinetics of 400 mg of indinavir/m2 combined with 125 mg of ritonavir/m2 every 12 h (q12h) in 14 human immunodeficiency virus type 1-infected children. The area under the concentration-time curve from 0 to 24 h and the minimum concentration of drug in serum for indinavir were similar to those for 800 mg of indinavir-100 mg of ritonavir q12h in adults, while the maximum concentration of drug in serum was slightly decreased, with geometric mean ratios (90% confidence intervals in parentheses) of 1.1 (0.87 to 1.3), 0.96 (0.60 to 1.5), and 0.80 (0.68 to 0.94), respectively.


2001 ◽  
Vol 45 (7) ◽  
pp. 2160-2162 ◽  
Author(s):  
P. Villani ◽  
P. Viale ◽  
L. Signorini ◽  
B. Cadeo ◽  
F. Marchetti ◽  
...  

ABSTRACT The purpose of this study was to evaluate the pharmacokinetics (PK) profile of oral levofloxacin in human immunodeficiency virus-positive patients in steady-state treatment with nelfinavir (NFV) or with efavirenz (EFV) and to determine the effects of levofloxacin on the PK parameters of these two antiretroviral agents. For levofloxacin, plasma samples were obtained at steady state during a 24-h dosing interval. Plasma NFV and EFV concentrations were evaluated before and after 4 days of levofloxacin treatment. Levofloxacin PK do not seem affected by NFV and EFV. There was no significant difference between NFV and EFV plasma levels obtained with and without levofloxacin.


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