scholarly journals Multiple-Dose Pharmacokinetics and Tolerability of Gemifloxacin Administered Orally to Healthy Volunteers

2001 ◽  
Vol 45 (2) ◽  
pp. 540-545 ◽  
Author(s):  
Ann Allen ◽  
Elizabeth Bygate ◽  
Marika Vousden ◽  
Stuart Oliver ◽  
Martin Johnson ◽  
...  
Keyword(s):  
Maximum Concentration ◽  
High Performance ◽  
Clinical Chemistry ◽  
Clinical Signs ◽  
Vital Signs ◽  
Terminal Phase ◽  
Multiple Dosing ◽  
Time Curve ◽  
Once Daily ◽  
Tract Infections

ABSTRACT Gemifloxacin mesylate (SB-265805-S, LB-20304a) is a potent, novel fluoroquinolone agent with a broad spectrum of antibacterial activity. The pharmacokinetics and tolerability of oral gemifloxacin were characterized in two parallel group studies in healthy male volunteers after doses of 160, 320, 480, and 640 mg once daily for 7 days. Multiple serum or plasma and urine samples were collected on days 1 and 7 and were analyzed for gemifloxacin by high-performance liquid chromatography (HPLC)–fluorescence (study 1) or HPLC-mass spectrometry (study 2). Safety assessments included vital signs, 12-lead electrocardiogram (ECG) readings, hematology, clinical chemistry, urinalysis, and adverse experience monitoring. Gemifloxacin was rapidly absorbed, with a time to maximum concentration of approximately 1 h after dosing followed by a biexponential decline in concentration. Generally, maximum concentration and area under the concentration-time curve (AUC) increased linearly with dose after either single or repeat doses. Mean ± standard deviation values of AUC0–τ on day 7 were 4.92 ± 1.08, 9.06 ± 2.20, 12.2 ± 3.69, and 20.1 ± 3.67 μg·h/ml following 160-, 320-, 480-, and 640-mg doses, respectively. The terminal-phase half-life was approximately 7 to 8 h, independent of dose, and was similar following single and repeated administrations. There was minimal accumulation of gemifloxacin after multiple dosing. Approximately 20 to 30% of the administered dose was excreted unchanged in the urine. The renal clearance was 160 ml/min on average after single and multiple doses, which was slightly greater than the accepted glomerular filtration rate (approximately 120 ml/min). These data show that the pharmacokinetics of gemifloxacin are linear and independent of dose. Gemifloxacin was generally well tolerated, although one subject was withdrawn from the study after 6 days at 640 mg for mild, transient elevations of alanine aminotransferase and aspartate aminotransferase not associated with any clinical signs or symptoms. There were no other significant changes in clinical chemistry, hematology or urinalysis parameters, vital signs, or ECG readings. In conclusion, the results of these studies, combined with the antibacterial spectrum and potency, support the further investigation of once-daily administration of gemifloxacin for indications such as respiratory tract and urinary tract infections.

scholarly journals Pharmacokinetics and Tolerability of Gemifloxacin (SB-265805) after Administration of Single Oral Doses to Healthy Volunteers

2000 ◽  
Vol 44 (6) ◽  
pp. 1604-1608 ◽  
Author(s):  
Ann Allen ◽  
Elizabeth Bygate ◽  
Stuart Oliver ◽  
Martin Johnson ◽  
Christopher Ward ◽  
...  
Keyword(s):  
High Performance ◽  
Clinical Chemistry ◽  
Vital Signs ◽  
Pharmacokinetic Profile ◽  
Terminal Phase ◽  
Time Curve ◽  
Once Daily ◽  
Elimination Half ◽  
Safety Assessments ◽  
Oral Doses

ABSTRACT Gemifloxacin (known as SB-265805 or LB-20304) is a potent, novel fluoroquinolone compound with a broad spectrum of antibacterial activity. The pharmacokinetics and tolerability of oral gemifloxacin were characterized in healthy male volunteers after a single dose of 20, 40, 80, 160, 320, 600, or 800 mg. Multiple serum and urine samples were collected and analyzed for gemifloxacin using high-performance liquid chromatography with fluorescence detection. Safety assessments included vital signs, 12-lead electrocardiogram readings, hematology, clinical chemistry, urinalysis, and adverse-experience monitoring. Gemifloxacin was rapidly absorbed after all doses. Maximum concentrations of gemifloxacin in serum (C max) were achieved approximately 1 h after dosing, after which concentrations in serum declined in a biexponential manner. Values ofC max and the area under the concentration-time curve in serum from 0 h to infinity (serum AUC0–∞) increased linearly with dose. Serum AUC0–∞ values (mean ± standard deviation) were 0.65 ± 0.01, 1.28 ± 0.22, 2.54 ± 0.31, 5.48 ± 1.24, 9.82 ± 2.70, 24.4 ± 7.1, and 31.4 ± 7.6 μg · h/ml following 20-, 40-, 80-, 160-, 320-, 600-, and 800-mg doses, respectively. The terminal phase elimination half-life was independent of dose, with an overall mean of 7.4 ± 2.0 h. The profiles indicated that the pharmacokinetic profile is suitable for a once-daily dosing regimen. Approximately 25 to 40% of the administered dose was excreted unchanged in the urine, and renal clearance (ca. 150 ml/min) was independent of dose. There were no significant changes in clinical chemistry, hematology, or urinalysis parameters, vital signs, or 12-lead electrocardiogram readings in subjects, irrespective of dose. The results of these studies support the further investigation of once-daily administration of gemifloxacin.

scholarly journals Pharmacokinetics of a Once-Daily Oral Dose of Moxifloxacin (Bay 12-8039), a New Enantiomerically Pure 8-Methoxy Quinolone

1999 ◽  
Vol 43 (11) ◽  
pp. 2793-2797 ◽  
Author(s):  
John T. Sullivan ◽  
Marilyn Woodruff ◽  
John Lettieri ◽  
Vipin Agarwal ◽  
George J. Krol ◽  
...  
Keyword(s):  
High Performance ◽  
Vital Signs ◽  
Blood Chemistry ◽  
Controlled Study ◽  
Pharmacokinetic Parameters ◽  
Fluorometric Detection ◽  
Double Blind ◽  
Time Curve ◽  
Once Daily ◽  
The Mean

ABSTRACT The pharmacokinetics, safety, and tolerability of oral moxifloxacin, a new 8-methoxy quinolone, were assessed in a randomized, double-blind, placebo-controlled study in which healthy male and female volunteers received either 400 mg of moxifloxacin once daily (n = 10) or a placebo once daily (n = 5) for 10 days. Plasma moxifloxacin concentrations on days 1 and 10 were measured by high-performance liquid chromatography and fluorometric detection. Standard pharmacokinetic parameters were estimated by noncompartmental methods. Natural logarithmic estimates for each pharmacokinetic variable of each subject were analyzed by a two-way analysis of variance. Hematology, blood chemistry, vital signs, and adverse events were monitored, and electrocardiograms (ECG) were performed. Plasma moxifloxacin concentrations of predicted therapeutic relevance were achieved in this study. For day 1, the mean maximum concentration of drug in serum (C max) and the area under the concentration-time curve from 0 to 24 h (AUC0–24) were 3.4 mg/liter and 30.2 mg · h/liter, respectively. Corresponding means on day 10 were 4.5 mg/liter and 48 mg · h/liter, respectively. On day 10, the mean elimination half-life was approximately 12 h. Plasma moxifloxacin concentrations exceeded the MIC for Streptococcus pneumoniae throughout the 24-h dosing period. The day 1 and day 10 mean AUC/MIC ratios were 121 and 192, respectively, and the meanC max/MIC ratios were 13 and 18, respectively. Moxifloxacin was well tolerated; no clinically relevant changes in the standard laboratory tests, vital signs, or ECG were observed. Pharmacokinetic parameters demonstrated linearity, and estimates of pharmacokinetic/pharmacodynamic ratios (AUC/MIC andC max/MIC) indicate that the regimen of 400-mg once daily should be effective for treating a variety of infections. Moxifloxacin was found to be safe and well tolerated in healthy volunteers when it was given as a single daily 400-mg dose for 10 days.

scholarly journals Pharmacokinetics of the New Ketolide Telithromycin (HMR 3647) Administered in Ascending Single and Multiple Doses

2001 ◽  
Vol 45 (1) ◽  
pp. 170-175 ◽  
Author(s):  
F. Namour ◽  
D. H. Wessels ◽  
M. H. Pascual ◽  
D. Reynolds ◽  
E. Sultan ◽  
...  
Keyword(s):  
Oral Dose ◽  
Plasma Concentrations ◽  
Dose Proportionality ◽  
Pharmacokinetic Parameters ◽  
Respiratory Pathogens ◽  
Multiple Dosing ◽  
Time Curve ◽  
Once Daily ◽  
Days Of Therapy ◽  
Tract Infections

ABSTRACT Telithromycin (HMR 3647) is a novel ketolide antimicrobial with good activity against both common and atypical respiratory pathogens, including many resistant strains. This randomized, three-period crossover study determined the dose proportionality of telithromycin pharmacokinetics after single and multiple dosing in healthy subjects. In each treatment period, subjects received a single oral dose of 400, 800 or 1,600 mg of telithromycin followed 4 days later by the same dose once daily for 7 days. Blood and urine samples were taken throughout the study for determination of pharmacokinetic parameters for telithromycin and RU 76363, its main metabolite. Telithromycin and RU 76363 achieved steady state within 2 to 3 days of once-daily dosing. A slight accumulation of telithromycin was observed after 7 days of therapy, with values of the area under the concentration-time curve from 0 to 24 h approximately 1.5 times higher than those achieved with the single dose. The pharmacokinetics of telithromycin and RU 76363 deviated moderately from dose proportionality. At a dose of 800 mg/day, telithromycin attained mean maximal and trough plasma concentrations of 2.27 and 0.070 mg/liter respectively. Elimination was biphasic; initial and terminal half-lives were 2.87 and 9.81 h for the 800-mg dose. Study medication was well tolerated, although adverse events tended to be more frequent at the 1,600-mg dose. This study showed that telithromycin was generally well tolerated and suggests that a once-daily 800-mg oral dose of telithromycin maintains an effective concentration in plasma for the treatment of respiratory tract infections involving the key respiratory pathogens.

scholarly journals Pharmacokinetics, Safety, and Tolerability of Ascending Single Doses of Moxifloxacin, a New 8-Methoxy Quinolone, Administered to Healthy Subjects

1998 ◽  
Vol 42 (8) ◽  
pp. 2060-2065 ◽  
Author(s):  
H. Stass ◽  
A. Dalhoff ◽  
D. Kubitza ◽  
U. Schühly
Keyword(s):  
Clinical Chemistry ◽  
Vital Signs ◽  
Terminal Phase ◽  
Pharmacokinetic Parameters ◽  
Active Metabolites ◽  
Double Blind ◽  
Time Curve ◽  
Plasma And Urine Samples ◽  
Higher Doses ◽  
Binding Level

ABSTRACT The pharmacokinetics of moxifloxacin were investigated in six studies after oral administration of 50, 100, 200, 400, 600, and 800 mg. Eight healthy male volunteers were included in each study. With doses of up to 200 mg the study was performed as a double-blind, randomized group comparison (n = 6 verum andn = 2 matched placebo); with the higher doses the study was conducted with a double-blind, randomized, crossover design. Safety and tolerability were assessed by evaluation of vital signs, electrocardiograms, electroencephalograms, clinical chemistry parameters, results of urinalysis, and adverse events. The drug was well tolerated. The concentrations of moxifloxacin in plasma, urine, and saliva were determined by a validated high-pressure liquid chromatography assay with fluorescence detection. In addition, plasma and urine samples were analyzed by a bioassay. A good correlation between both methods was seen, indicating an absence of major active metabolites. The mean maximum concentrations of moxifloxacin in plasma (C max) ranged from 0.29 mg/liter (50-mg dose) to 4.73 mg/liter (800-mg dose) and were reached 0.5 to 4 h following drug administration. After reaching theC max, plasma moxifloxacin concentrations declined in a biphasic manner. Within 4 to 5 h they fell to about 30 to 55% of the C max, and thereafter a terminal half-life of 11 to 14 h accounted for the major part of the area under the concentration-time curve (AUC). During the absorption phase concentrations in saliva were even higher than those in plasma, whereas in the terminal phase a constant ratio of the concentration in saliva/concentration in plasma of between 0.5 and 1 was observed, indicating a correlation between unbound concentrations in plasma and levels in saliva (protein binding level, approximately 48%). AUC and C max increased proportionally to the dose over the whole range of doses investigated. Urinary excretion amounted to approximately 20% of the dose. Data on renal clearance (40 to 51 ml/min/1.73 m2) indicated partial tubular reabsorption of the drug. The pharmacokinetic parameters derived from compartmental and noncompartmental analyses were in good agreement. The kinetics could be described best by fitting the data to a two-compartment body model.

scholarly journals Comparison of Plasma, Epithelial Lining Fluid, and Alveolar Macrophage Concentrations of Solithromycin (CEM-101) in Healthy Adult Subjects

2012 ◽  
Vol 56 (10) ◽  
pp. 5076-5081 ◽  
Author(s):  
Keith A. Rodvold ◽  
Mark H. Gotfried ◽  
J. Gordon Still ◽  
Kay Clark ◽  
Prabhavathi Fernandes
Keyword(s):  
Steady State ◽  
High Performance ◽  
Healthy Adult ◽  
Plasma Concentrations ◽  
Epithelial Lining ◽  
Time Curve ◽  
Epithelial Lining Fluid ◽  
Once Daily ◽  
Drug Concentrations ◽  
The Mean

ABSTRACTThe steady-state concentrations of solithromycin in plasma were compared with concomitant concentrations in epithelial lining fluid (ELF) and alveolar macrophages (AM) obtained from intrapulmonary samples during bronchoscopy and bronchoalveolar lavage (BAL) in 30 healthy adult subjects. Subjects received oral solithromycin at 400 mg once daily for five consecutive days. Bronchoscopy and BAL were carried out once in each subject at either 3, 6, 9, 12, or 24 h after the last administered dose of solithromycin. Drug concentrations in plasma, ELF, and AM were assayed by a high-performance liquid chromatography-tandem mass spectrometry method. Solithromycin was concentrated extensively in ELF (range of mean [± standard deviation] concentrations, 1.02 ± 0.83 to 7.58 ± 6.69 mg/liter) and AM (25.9 ± 20.3 to 101.7 ± 52.6 mg/liter) in comparison with simultaneous plasma concentrations (0.086 ± 0.070 to 0.730 ± 0.692 mg/liter). The values for the area under the concentration-time curve from 0 to 24 h (AUC0–24values) based on mean and median ELF concentrations were 80.3 and 63.2 mg · h/liter, respectively. The ratio of ELF to plasma concentrations based on the mean and median AUC0–24values were 10.3 and 10.0, respectively. The AUC0–24values based on mean and median concentrations in AM were 1,498 and 1,282 mg · h/L, respectively. The ratio of AM to plasma concentrations based on the mean and median AUC0–24values were 193 and 202, respectively. Once-daily oral dosing of solithromycin at 400 mg produced steady-state concentrations that were significantly (P< 0.05) higher in ELF (2.4 to 28.6 times) and AM (44 to 515 times) than simultaneous plasma concentrations throughout the 24-h period after 5 days of solithromycin administration.

scholarly journals Drug Interactions Between Dolutegravir and Artemether-Lumefantrine or Artesunate-Amodiaquine

2018 ◽  
Author(s):  
Stephen I Walimbwa ◽  
Mohammed Lamorde ◽  
Catriona Waitt ◽  
Julian Kaboggoza ◽  
Laura Else ◽  
...  
Keyword(s):  
Maximum Concentration ◽  
Geometric Mean ◽  
Compartmental Analysis ◽  
Sub Saharan Africa ◽  
Pharmacokinetic Studies ◽  
Serious Adverse Events ◽  
Time Curve ◽  
Once Daily ◽  
Trough Concentrations ◽  
Sub Saharan

ABSTRACTAcross sub-Saharan Africa, patients with HIV on antiretrovirals often get malaria and need cotreatment with artemisinin-containing therapies. We undertook two pharmacokinetic studies in healthy volunteers, using standard adult doses of artmether-lumefantrine (AL) or artesunate-amodiaquine (AS-AQ) given with 50mg once daily dolutegravir (DTG) to investigate the drug-drug interaction between artmether-lumefantrine or artesunate-amodiaquine and DTG. The DTG/artmether-lumefantrine interaction was evaluated in a two-way cross-over study and measured artemether (ARM), dihydroartemisinin (DHA), lumefantrine (LF), desbutyl-lumefantrine (DBL) over 264h. The DTG/artesunate-amodiaquine interaction was investigated using a parallel study design due to long half-life of the amodiaquine metabolite, desethylamodiaquine (DEAQ) and measured artesunate (ARS), amodiaquine (AQ), DEAQ over 624h. Non-compartmental analysis was performed, and geometric mean ratios and 90% confidence intervals generated for evaluation of both interactions. Dolutegravir did not significantly change the maximum concentration in plasma, time to maximum concentration and area under the concentration-time curve (AUC) for ARM, DHA, LF and DBL nor significantly alter AUC for ARS, DHA, AQ and DEAQ. Co-administration of dolutegravir with AL resulted in a 37% decrease in DTG trough concentrations. Co-administration of dolutegravir with AS-AQ resulted in a decrease of approximately 42% and 24% in DTG trough concentrations and AUC respectively. Study drugs were well-tolerated with no serious adverse events. Standard doses of artmether-lumefantrine and artesunate-amodiaquine should be used in patients receiving DTG. The significant decreases in DTG trough concentrations with artemether-lumefantrine and artesunate-amodiaquine and DTG exposure with artesunate-amodiaquine are unlikely to be of clinical significance as DTG trough concentrations were above DTG target concentrations of 64ng/mL.

scholarly journals Administration of aminoglycosides to hemodialysis patients immediately before dialysis: a new dosing modality.

1997 ◽  
Vol 41 (12) ◽  
pp. 2597-2601 ◽  
Author(s):  
H Matsuo ◽  
J Hayashi ◽  
K Ono ◽  
K Andoh ◽  
Y Andoh ◽  
...  
Keyword(s):  
High Performance ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Cellulose Triacetate ◽  
The Body ◽  
High Rate ◽  
Complete Disappearance ◽  
Time Curve ◽  
Once Daily ◽  
Ethylene Vinyl Alcohol ◽  
Concentration Time

We describe a new modality for administering aminoglycosides to hemodialysis (HD) patients, namely, a modification of the once-daily regimen which consists of administering the aminoglycosides over 60 min by drip infusion just before each HD session, with a preplanned peak concentration being reached at the beginning of the session and then with a rapidly decreasing concentration being achieved by the start of HD. The area under the concentration-time curve (AUC), i.e., the accumulation of the drug in the body, is thus minimized by this modality. Arbekacin (ABK) was given at a dose of 2 mg/kg of body weight to 10 HD patients infected with methicillin-resistant Staphylococcus aureus (MRSA) for 2 weeks (six sessions in total), resulting in the complete disappearance of MRSA in 5 patients. A high rate of elimination of ABK was attained for each patient while the patient was on HD (range, 0.20 to 0.42 h-1; mean 0.28 +/- 0.08 h-1) by using high-performance dialyzers provided with membranes made of either polymethylmethacrylate, cellulose triacetate (CTA), or ethylene vinyl alcohol. The best results were obtained with the CTA membrane, as revealed by the overall mass transfer coefficient (Ko). The AUC in the simulation model for the variation in the serum ABK concentration in this modality was calculated to be 40% of that of the conventional post-HD dosing modality, suggesting that a much higher dose could be administered to HD patients who receive HD thrice weekly (4 h per session), giving, e.g., 4 mg/kg initially and before the HD sessions, when there is an interval of 68 h from HD session to HD session, and giving 2 mg/kg before the other sessions.

scholarly journals Polymorphisms in CYP1A2, CYP2C9 and ABCB1 affect agomelatine pharmacokinetics

2019 ◽  
Vol 33 (4) ◽  
pp. 522-531 ◽  
Author(s):  
Miriam Saiz-Rodríguez ◽  
Dolores Ochoa ◽  
Carmen Belmonte ◽  
Manuel Román ◽  
Danilo Vieira de Lara ◽  
...  
Keyword(s):  
Maximum Concentration ◽  
High Performance ◽  
Genotype Distribution ◽  
Cytochrome P450 Enzymes ◽  
Time Curve ◽  
P Glycoprotein ◽  
Treatment Of Depression ◽  
Mass Spectrometry Detector ◽  
Polymerase Chain ◽  
Cyp1a2 Genotype

Background: Agomelatine is an agonist of the melatoninergic receptors used for the treatment of depression. Our aim was to evaluate the effect of genetic polymorphisms in metabolising enzymes and the P-glycoprotein transporter on agomelatine pharmacokinetics and pharmacodynamics. Methods: Twenty-eight healthy volunteers receiving a single 25 mg oral dose of agomelatine, were genotyped for nine polymorphisms in cytochrome P450 enzymes ( CYP1A2, CYP2C9 and CYP2C19) and adenosine triphosphate-binding cassette subfamily B member 1 ( ABCB1), by real-time polymerase chain reaction . Agomelatine concentrations were measured by high performance liquid chromatography coupled to a tandem mass spectrometry detector. Results: We calculated a CYP1A2 activity score that was directly correlated with agomelatine pharmacokinetics. Individuals with a decreased enzyme activity (*1C carriers) had a lower clearance and accumulated higher concentrations of agomelatine. In contrast, individuals with a high CYP1A2 inducibility (*1F or *1B carriers) showed an extensive clearance and lower agomelatine concentrations. The apparently marked differences between races were due to the different CYP1A2 genotype distribution. CYP2C9 intermediate/poor metabolisers showed a higher area under the concentration-time curve and maximum concentration. ABCB1 G2677T/A polymorphism affected the time to reach maximum concentration, as subjects carrying A/A+A/T genotypes showed higher values. No association was found for CYP2C19 phenotype. Agomelatine did not produce any change in blood pressure, heart rate or QT interval. Conclusions: CYP1A2 polymorphisms affect agomelatine pharmacokinetics. CYP1A2 phenotype inferred from the genotyping of CYP1A2*1C, *1F and *1B alleles might be a potential predictor of agomelatine exposure. ABCB1 G2677T/A could affect agomelatine absorption, as subjects with A/A+A/T genotypes had lower agomelatine concentration and they take more time to reach the maximum concentration.

scholarly journals Once-Daily Dosing in Dogs Optimizes Daptomycin Safety

2000 ◽  
Vol 44 (11) ◽  
pp. 2948-2953 ◽  
Author(s):  
F. B. Oleson ◽  
C. L. Berman ◽  
J. B. Kirkpatrick ◽  
K. S. Regan ◽  
J.-J. Lai ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Maximum Concentration ◽  
Time Curve ◽  
Once Daily ◽  
Gram Positive Bacteria ◽  
Concentration Time ◽  
Serum Creatine Phosphokinase ◽  
Lower Maximum ◽  
Resistant Strains ◽  
Lipopeptide Antibiotic

ABSTRACT Daptomycin is a novel lipopeptide antibiotic with potent bactericidal activity against most clinically important gram-positive bacteria, including resistant strains. Daptomycin has been shown to have an effect on skeletal muscle. To guide the clinical dosing regimen with the potential for the least effect on skeletal muscle, two studies were conducted with dogs to compare the effects of repeated intravenous administration every 24 h versus every 8 h for 20 days. The data suggest that skeletal-muscle effects were more closely related to the dosing interval than to either the maximum concentration of the drug in plasma or the area under the concentration-time curve. Both increases in serum creatine phosphokinase activity and the incidence of myopathy observed at 25 mg/kg of body weight every 8 h were greater than those observed at 75 mg/kg every 24 h despite the lower maximum concentration of drug in plasma. Similarly, the effects observed at 25 mg/kg every 8 h were greater than those observed at 75 mg/kg every 24 h at approximately the same area under the concentration-time curve from 0 to 24 h. Once-daily administration appeared to minimize the potential for daptomycin-related skeletal-muscle effects, possibly by allowing for more time between doses for repair of subclinical effects. Thus, these studies with dogs suggest that once-daily dosing of daptomycin in humans should have the potential to minimize skeletal-muscle effects. In fact, interim results of ongoing clinical trials, which have focused on once-daily dosing, appear to be consistent with this conclusion.

scholarly journals Steady-State Pharmacokinetics of Abacavir in Plasma and Intracellular Carbovir Triphosphate following Administration of Abacavir at 600 Milligrams Once Daily and 300 Milligrams Twice Daily in Human Immunodeficiency Virus-Infected Subjects

2009 ◽  
Vol 53 (4) ◽  
pp. 1532-1538 ◽  
Author(s):  
Graeme Moyle ◽  
Marta Boffito ◽  
Carl Fletcher ◽  
Chris Higgs ◽  
Phillip E. Hay ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
High Performance ◽  
Pharmacokinetic Parameters ◽  
Virologic Suppression ◽  
Open Label ◽  
Time Curve ◽  
Mixed Effect ◽  
Once Daily ◽  
Immunodeficiency Virus ◽  
And Gender

ABSTRACT Abacavir (ABC) is administered either at 600 mg once daily (ABC 600 mg QD) or 300 mg twice daily (ABC 300 mg BID) in anti-human immunodeficiency virus (anti-HIV) combination therapy. Although ABC plasma pharmacokinetics following each regimen has been well defined, no study has directly compared the regimens with respect to pharmacokinetics of ABC's active intracellular anabolite, carbovir-triphosphate (CBV-TP). In an open-label, two-period, crossover study, 34 HIV-infected male and female subjects stabilized on antiretroviral regimens containing either ABC 600 mg QD or ABC 300 mg BID received their usual doses on days −1 and 1 and then switched regimens for days 2 to 11. Serial blood samples collected on days 1 and 11 were assayed for plasma ABC and intracellular CBV-TP concentrations using validated high-performance liquid chromatography-tandem mass spectrometry methods. Pharmacokinetic parameters were calculated using noncompartmental methods. Analysis of variance with a mixed-effect model was performed for treatment and gender comparisons. In 27 evaluable subjects, the regimens provided bioequivalent ABC daily areas under the concentration-time curve from 0 to 24 h (AUC0-24) and comparable CBV-TP concentrations at the end of the dosing interval (C τ). As expected, ABC QD resulted in 109% higher ABC maximum concentrations of drug in plasma (C max) than did ABC BID. ABC QD also resulted in 32% higher CBV-TP AUC0-24 and 99% higher CBV-TP C max than did ABC BID. Females had a 38% higher weight-adjusted ABC AUC0-24 and 81% higher weight-adjusted CBV-TP AUC0-24 than did males. Virologic suppression was maintained during regimen switch, and no tolerability differences between regimens were observed. In conclusion, this study showed that ABC 600 mg QD and ABC 300 mg BID regimens led to similar intracellular CBV-TP C τ values, thus providing pharmacokinetic support for the interchangeability of these two regimens. Women had higher intracellular CBV-TP exposure than did men.

Sign in / Sign up

Export Citation Format

Share Document