scholarly journals Absence of effect of trimethoprim-sulfamethoxazole on pharmacokinetics of zidovudine in patients infected with human immunodeficiency virus.

1996 ◽  
Vol 40 (1) ◽  
pp. 230-233 ◽  
Author(s):  
E Cañas ◽  
J Pachon ◽  
F Garcia-Pesquera ◽  
J R Castillo ◽  
P Viciana ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Oral Administration ◽  
Pharmacokinetic Parameters ◽  
Concomitant Therapy ◽  
Concentration Time ◽  
Immunodeficiency Virus ◽  
Standard Deviations

Pharmacokinetic parameters of zidovudine (ZDV) were not altered in 16 patients receiving concomitant therapy with ZDV and trimethoprim-sulfamethoxazole by oral administration. ZDV areas under the concentration-time curves were (means +/- standard deviations) 1.80 +/- 0.70 and 1.69 +/- 0.64 micrograms.h/ml in the absence and presence of trimethoprim-sulfamethoxazole, respectively. ZDV clearances were 1.57 +/- 0.61 and 1.74 +/- 0.66 liters/h/kg, respectively.

scholarly journals Pilot Pharmacokinetic Study of Human Immunodeficiency Virus-Infected Patients Receiving Tenofovir Disoproxil Fumarate (TDF): Investigation of Systemic and Intracellular Interactions between TDF and Abacavir, Lamivudine, or Lopinavir-Ritonavir

2009 ◽  
Vol 53 (5) ◽  
pp. 1937-1943 ◽  
Author(s):  
Alain Pruvost ◽  
Eugènia Negredo ◽  
Frédéric Théodoro ◽  
Jordi Puig ◽  
Mikaël Levi ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Pharmacokinetic Parameters ◽  
Reverse Transcriptase Inhibitors ◽  
Plasma Exposure ◽  
Time Curve ◽  
Residual Concentration ◽  
Concentration Time ◽  
Immunodeficiency Virus ◽  
Liquid Chromatography Tandem Mass

ABSTRACT Previous work has demonstrated the existence of systemic interaction between tenofovir (TFV) disoproxil fumarate (TDF) and didanosine as well as between TDF and lopinavir-ritonavir (LPV/r). Here we investigated TDF interactions with the nucleoside reverse transcriptase inhibitors (NRTIs) lamivudine (3TC) and abacavir (ABC), comparing both the concentrations of nucleoside/nucleotide reverse transcriptase inhibitors in plasma and the intracellular concentrations of their triphosphate metabolites (NRTI-TP) for human immunodeficiency virus-infected patients receiving these NRTIs with TDF and after 4 weeks of TDF interruption. We also looked at interactions between TDF-ABC and LPV/r, comparing patients receiving or not receiving LPV/r. Blood samples were taken at baseline and at 1, 2, and 4 h after dosing. Liquid chromatography-tandem mass spectrometry was used to measure NRTIs and NRTI-TPs. Statistical analyses were performed on pharmacokinetic parameters: the area under the concentration-time curve from 0 to 4 h (AUC0-4), the maximum concentration of the drug (C max), and the residual concentration of the drug at the end of the dosing interval (C trough) for plasma and the AUC0-4 and C trough for intracellular data. Among the groups of patient discontinuing TDF, the very long intracellular half-life of elimination (150 h) of TFV-DP (the diphosphorylated metabolite of TFV, corresponding to a triphosphorylated species) was confirmed. Comparison between groups as well as the longitudinal study showed no significant systemic or intracellular interaction between TDF and ABC or 3TC. Significant differences were observed between patients receiving LVP/r and those receiving nevirapine. For ABC, plasma exposure was decreased (40%) under LVP/r, while, in contrast, plasma exposure to TFV was increased by 50% and the intracellular TFV-DP AUC0-4 was increased by 59%. A trend for a gender effect was observed for TFV-DP at the intracellular level, with higher and C trough values for women.

scholarly journals Safety and Pharmacokinetics of Bevirimat (PA-457), a Novel Inhibitor of Human Immunodeficiency Virus Maturation, in Healthy Volunteers

2007 ◽  
Vol 51 (9) ◽  
pp. 3063-3066 ◽  
Author(s):  
David E. Martin ◽  
Robert Blum ◽  
John Wilton ◽  
Judy Doto ◽  
Hal Galbraith ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Oral Administration ◽  
Half Life ◽  
Peak Plasma ◽  
Plasma Concentrations ◽  
Pharmacokinetic Parameters ◽  
Double Blind Study ◽  
Immunodeficiency Virus ◽  
Oral Doses

ABSTRACT Bevirimat (BVM; formerly known as PA-457) is a novel inhibitor of human immunodeficiency virus (HIV) maturation that is being developed for the treatment of HIV infection. The pharmacokinetics of this agent in healthy male volunteers were studied in a randomized, double-blind study in which the participants received single oral doses of placebo (n = 8) or escalating doses of BVM at 25, 50, 100, or 250 mg (n = 6 per dose); escalation was performed only after the pharmacokinetics and safety of the preceding dose had been evaluated. Plasma was collected over 480 h after dosing and urine was collected over 48 h after dosing for determination of the values of pharmacokinetic parameters. BVM was well absorbed after oral administration, with peak plasma concentrations being achieved 1 to 3 h after dosing. The half-life was 60 to 80 h. The exposure assessed by determination of the peak concentration and the area under the concentration-time curve was dose proportional. Single oral doses of BVM were well tolerated: there were no dose-limiting toxicities, and no serious adverse events were reported. These findings suggest that that BVM offers a favorable pharmacokinetic profile, with predictable pharmacokinetics following the oral administration of single doses. The long half-life of BVM may facilitate once-daily dosing.

scholarly journals Pharmacokinetics of Azithromycin Administered Alone and with Atovaquone in Human Immunodeficiency Virus-Infected Children

1999 ◽  
Vol 43 (6) ◽  
pp. 1516-1519 ◽  
Author(s):  
Leock Y. Ngo ◽  
Ram Yogev ◽  
Wayne M. Dankner ◽  
Walter T. Hughes ◽  
Sandra Burchett ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Steady State ◽  
Pharmacokinetic Parameters ◽  
Time Curve ◽  
Concentration Time ◽  
Significant Difference ◽  
Immunodeficiency Virus ◽  
The Mean ◽  
Clinically Significant ◽  
To Receive

ABSTRACT To evaluate if atovaquone (ATQ) interacts pharmacokinetically with azithromycin (AZ) in human immunodeficiency virus-infected children, 10 subjects (ages, 4 to 13 years) were randomized in a crossover study to receive AZ (5 mg/kg/day) alone (ALONE) or AZ (5 mg/kg/day) and ATQ (30 mg/kg/day) simultaneously (SIM) prior to receiving AZ and ATQ staggered by 12 h. Despite a lack of significant difference in the mean AZ pharmacokinetic parameters, the steady-state values of AZ’s area under the concentration-time curve from 0 to 24 h and maximum concentration in serum were consistently lower (n = 7 of 7) for the SIM regimen than they were for the ALONE regimen. A larger study will be required to determine if ATQ affects AZ pharmacokinetics and efficacy in a clinically significant manner.

scholarly journals Tolerance and Pharmacokinetic Interactions of Rifabutin and Clarithromycin in Human Immunodeficiency Virus-Infected Volunteers

1998 ◽  
Vol 42 (3) ◽  
pp. 631-639 ◽  
Author(s):  
Richard Hafner ◽  
James Bethel ◽  
Maureen Power ◽  
Bernard Landry ◽  
Mary Banach ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Combination Therapy ◽  
Single Agent ◽  
Pharmacokinetic Analysis ◽  
Pharmacokinetic Parameters ◽  
Time Curve ◽  
Concentration Time ◽  
Pharmacokinetic Interactions ◽  
Immunodeficiency Virus ◽  
Gastrointestinal Adverse Events

ABSTRACT This study evaluated the tolerance and potential pharmacokinetic interactions between clarithromycin (500 mg every 12 h) and rifabutin (300 mg daily) in clinically stable human immunodeficiency virus-infected volunteers with CD4 counts of <200 cells/mm3. Thirty-four subjects were randomized equally to either regimen A or regimen B. On days 1 to 14, subjects assigned to regimen A received clarithromycin and subjects assigned to regimen B received rifabutin, and then both groups received both drugs on days 15 to 42. Of the 14 regimen A and the 15 regimen B subjects who started combination therapy, 1 subject in each group prematurely discontinued therapy due to toxicity, but 19 of 29 subjects reported nausea, vomiting, and/or diarrhea. Pharmacokinetic analysis included data for 11 regimen A and 14 regimen B subjects. Steady-state pharmacokinetic parameters for single-agent therapy (day 14) and combination therapy (day 42) were compared. Regimen A resulted in a mean decrease of 44% (P = 0.003) in the clarithromycin area under the plasma concentration-time curve (AUC), while there was a mean increase of 57% (P = 0.004) in the AUC of the clarithromycin metabolite 14-OH-clarithromycin. Regimen B resulted in a mean increase of 99% (P = 0.001) in the rifabutin AUC and a mean increase of 375% (P < 0.001) in the AUC of the rifabutin metabolite 25-O-desacetyl-rifabutin. The usefulness of this combination for prophylaxis of Mycobacterium avium infections is limited by frequent gastrointestinal adverse events. Coadministration of clarithromycin and rifabutin results in significant bidirectional pharmacokinetic interactions. The resulting increase in rifabutin levels may explain the increased frequency of uveitis observed with concomitant use of these drugs.

scholarly journals Serum and Cerebrospinal Fluid Pharmacokinetics of Intravenous and Oral Lamivudine in Human Immunodeficiency Virus-Infected Children

1998 ◽  
Vol 42 (12) ◽  
pp. 3187-3192 ◽  
Author(s):  
Brigitta U. Mueller ◽  
Linda L. Lewis ◽  
Geoffrey J. Yuen ◽  
Maureen Farley ◽  
Amy Keller ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Cerebrospinal Fluid ◽  
Body Weight ◽  
Oral Administration ◽  
Drug Concentration ◽  
Serum Drug Concentration ◽  
Time Curve ◽  
Concentration Time ◽  
Immunodeficiency Virus ◽  
The Mean

ABSTRACT We studied the pharmacokinetics of intravenously and orally administered lamivudine at six dose levels ranging from 0.5 to 10 mg/kg of body weight in 52 children with human immunodeficiency virus infection. A two-compartment model with first-order elimination from the central compartment was simultaneously fitted to the serum drug concentration-time data obtained after intravenous and oral administration. The maximal concentration at the end of the 1-h intravenous infusion and the area under the concentration-time curve after oral and intravenous administration increased proportionally with the dose. The mean clearance of lamivudine (± standard deviation) in the children was 0.53 ± 0.19 liter/kg/h (229 ± 77 ml/min/m2 of body surface area), and the mean half-lives at the distribution and elimination phases were 0.23 ± 0.18 and 2.2 ± 2.1 h, respectively. Clearance was age dependent when normalized to body weight but age independent when normalized to body surface area. Lamivudine was rapidly absorbed after oral administration, and 66% ± 25% of the oral dose was absorbed. Serum lamivudine concentrations were maintained above 1 μM for ≥8 h of 24 h on the twice daily oral dosing schedule with doses of ≥2 mg/kg. The cerebrospinal fluid drug concentration measured 2 to 4 h after the dose was 12% (range, 0 to 46%) of the simultaneously measured serum drug concentration. A limited-sampling strategy was developed to estimate the area under the concentration-time curve for concentrations in serum at 2 and 6 h.

scholarly journals Pharmacokinetics of lamivudine in human immunodeficiency virus-infected patients with renal dysfunction.

1996 ◽  
Vol 40 (6) ◽  
pp. 1514-1519 ◽  
Author(s):  
A E Heald ◽  
P H Hsyu ◽  
G J Yuen ◽  
P Robinson ◽  
P Mydlow ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Renal Function ◽  
Renal Impairment ◽  
Normal Renal Function ◽  
Severe Renal Impairment ◽  
Moderate Renal Impairment ◽  
Pharmacokinetic Parameters ◽  
Geometric Means ◽  
Immunodeficiency Virus

The purpose of this study was to determine the safety and pharmacokinetics of lamivudine (3TC), a nucleoside analog that has shown potent in vitro and recent in vivo activity against human immunodeficiency virus. Sixteen human immunodeficiency virus-infected patients, six with normal renal function (creatinine clearance [CLCR], > or = 60 ml/min), four with moderate renal impairment (CLCR, 10 to 40 ml/min), and six with severe renal impairment (CLCR, < 10 ml/min), were enrolled in the study. After an overnight fast, patients were administered 300 mg of 3TC orally. Blood was obtained before 3TC administration and 0.25, 0.5, 0.75, 1, 1.5, 2, 3, 4, 6, 8, 10, 12, 16, 24, 32, 40, and 48 h afterward. Timed urine collections were performed for patients able to produce urine. Serum and urine were assayed for 3TC by reverse-phase high-performance liquid chromatography with UV detection. Pharmacokinetic parameters were calculated by using standard noncompartmental techniques. The peak concentration of 3TC increased with decreasing renal function; geometric means were 2,524, 3,538, and 5,684 ng/ml for patients with normal renal function, moderate renal impairment, and severe renal impairment, respectively. The terminal half-life also increased with decreasing renal function; geometric means were 11.5, 14.1, and 20.7 h for patients with normal renal function, moderate renal impairment, and severe renal impairment, respectively. Both oral and renal clearances were linearly correlated with CLCR. A 300-mg dose of 3TC was well tolerated by all three patient groups. The pharmacokinetics of 3TC is profoundly affected by impaired renal function. Dosage adjustment, by either dose reduction or lengthening of the dosing interval, is warranted.

scholarly journals Pharmacologic Characteristics of Indinavir, Didanosine, and Stavudine in Human Immunodeficiency Virus-Infected Children Receiving Combination Therapy

2000 ◽  
Vol 44 (4) ◽  
pp. 1029-1034 ◽  
Author(s):  
Courtney V. Fletcher ◽  
Richard C. Brundage ◽  
Rory P. Remmel ◽  
Linda M. Page ◽  
Dennis Weller ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Trough Concentration ◽  
Area Under The Curve ◽  
Hiv Protease ◽  
Pharmacokinetic Parameters ◽  
Hiv Protease Inhibitors ◽  
Hiv Rna ◽  
Immunodeficiency Virus ◽  
Dosing Regimens ◽  
Outcomes For Children

ABSTRACT The use of human immunodeficiency virus (HIV) protease inhibitors in children has lagged behind that in adults because of the lack of suitable pediatric formulations and information on safe and effective dosing regimens. This study was designed to obtain pharmacokinetic information on indinavir, administered to HIV-infected children also receiving therapy with two nucleoside agents, and to explore relationships between pharmacokinetic parameters and anti-HIV effect. Indinavir was initiated at a dose of 500 mg/m2 every 8 h. Plasma indinavir concentrations were measured every 4 weeks; the dose or dosing interval was adjusted to maintain trough concentrations of ≥0.1 mg/liter. All children were evaluated clinically at baseline and every 4 weeks. Plasma HIV RNA was quantitated at baseline and at weeks 4, 12, and 24. Eighteen children participated in this study. The average daily dose of indinavir was 2,043 mg/m2; nine children received indinavir at 6-h intervals. Pharmacokinetic characteristics of indinavir (mean ± standard deviation) were the following: oral clearance, 1.4 ± 0.5 liters/h/kg; half-life, 1.1 ± 0.43 h; and trough concentration, 0.29 ± 0.32 mg/liter. In nine children that completed 24 weeks of therapy, the baseline-to-week-24 change in HIV RNA level was related to indinavir trough concentration and didanosine area under the curve. This study illustrates the ability to obtain pharmacokinetic information from children during routine clinic visits and to use this information to provide a safeguard against underdosing. The incorporation of pharmacologic knowledge with virologic, immunologic, and behavioral considerations should result in improved clinical outcomes for children infected with HIV.

scholarly journals Multidose Pharmacokinetics of Ritonavir and Zidovudine in Human Immunodeficiency Virus-Infected Patients

1998 ◽  
Vol 42 (7) ◽  
pp. 1788-1793 ◽  
Author(s):  
Allen Cato ◽  
Jiang Qian ◽  
Ann Hsu ◽  
Benjamin Levy ◽  
John Leonard ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Adverse Event ◽  
Dosage Adjustment ◽  
Elimination Rate ◽  
Time Curve ◽  
Safety And Efficacy ◽  
Concentration Time ◽  
Immunodeficiency Virus ◽  
Asymptomatic Human Immunodeficiency Virus

ABSTRACT The effect of coadministration of ritonavir and zidovudine (ZDV) on the pharmacokinetics of these drugs was investigated in a three-period, multidose, crossover study. Eighteen asymptomatic, human immunodeficiency virus-positive men were assigned randomly to six different sequences of the following three regimens: ZDV (200 mg every 8 h [q8h]) alone for 4 days, ritonavir (300 mg q6h) alone for 4 days, and ZDV with ritonavir for 4 days. Ritonavir pharmacokinetics were unaffected by coadministration with ZDV. However, ZDV exposure was reduced by about 26% (P < 0.05) in the presence of ritonavir. The maximum concentration in (C max) of ZDV plasma decreased from 748 ± 375 (mean ± standard deviation) to 546 ± 296, and area under the concentration-time curve from 0 to 24 h (AUC0–24) decreased from 3,052 ± 1,007 to 2,261 ± 715 when coadministered with ritonavir. In contrast, the ZDV elimination rate constant was unaffected by ritonavir, suggesting that there was no change in ZDV systemic metabolism. Correspondingly, differences in ZDV-glucuronide C max and AUC were not statistically significantly different between regimens (P > 0.31). Also, there were no apparent differences in the formation of 3′-amino-3′-deoxythymidine or in the adverse event profiles between the regimens. The lack of change in ritonavir pharmacokinetics suggests that dosage adjustment of ritonavir is unnecessary when it is administered concurrently with ZDV. The clinical relevance of a 26% reduction in ZDV exposure when ZDV is administered with ritonavir is unknown. In addition to other multidrug regimens, the long-term safety and efficacy of coadministration of ritonavir and ZDV is being investigated.

scholarly journals Pharmacokinetics of zidovudine after rectal administration in human immunodeficiency virus-infected patients.

1997 ◽  
Vol 41 (5) ◽  
pp. 1143-1145 ◽  
Author(s):  
U Wintergerst ◽  
B Rolinski ◽  
J R Bogner ◽  
G Notheis ◽  
F D Goebel ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Oral Intake ◽  
Pharmacokinetic Profile ◽  
Rectal Administration ◽  
Beta Phase ◽  
Time Curve ◽  
Concentration Time ◽  
Release Device ◽  
Immunodeficiency Virus ◽  
The Mean

We evaluated the pharmacokinetics of rectally administered zidovudine (ZDV) in 10 human immunodeficiency virus-infected adults. After rectal administration of an aqueous ZDV solution (250 mg of ZDV), mean peak ZDV levels were 1.3 +/- 0.7 micromol/liter (mean +/- standard deviation) versus 5.0 +/- 2.2 micromol/liter (P < 0.0001) after oral intake of a 250-mg ZDV capsule. The half-life at beta phase was 87.8 +/- 39.6 min for rectally administered ZDV versus 55.8 +/- 20.1 min (P = 0.035) for orally administered ZDV. The mean area under the concentration-time curve from 0 min to infinity was 232 +/- 181 micromol/liter x min after rectal administration versus 362 +/- 110 micromol/liter x min after oral intake. Although the two routes were not bioequivalent, ZDV was absorbed considerably after rectal administration, with a pharmacokinetic profile resembling that of a sustained-release device.

scholarly journals Effects of Valproic Acid Coadministration on Plasma Efavirenz and Lopinavir Concentrations in Human Immunodeficiency Virus-Infected Adults

2004 ◽  
Vol 48 (11) ◽  
pp. 4328-4331 ◽  
Author(s):  
Robert DiCenzo ◽  
Derick Peterson ◽  
Kim Cruttenden ◽  
Gene Morse ◽  
Garret Riggs ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Valproic Acid ◽  
Geometric Mean ◽  
Pharmacokinetic Parameters ◽  
Time Curve ◽  
Blood Samples ◽  
Immunodeficiency Virus ◽  
Before And After ◽  
Trough Concentrations ◽  
Hiv 1

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.

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