scholarly journals Continuous versus Short-Term Infusion of Cefuroxime: Assessment of Concept Based on Plasma, Subcutaneous Tissue, and Bone Pharmacokinetics in an Animal Model

2014 ◽  
Vol 59 (1) ◽  
pp. 67-75 ◽  
Author(s):  
Mikkel Tøttrup ◽  
Bo M. Bibby ◽  
Tore F. Hardlei ◽  
Mats Bue ◽  
Sigrid Kerrn-Jespersen ◽  
...  
Keyword(s):  
Continuous Infusion ◽  
Subcutaneous Tissue ◽  
Pharmacokinetic Parameters ◽  
Pharmacokinetic Data ◽  
Tissue Penetration ◽  
Short Term ◽  
Concentration Data ◽  
Time Curve ◽  
Infusion Group ◽  
Tissue Pharmacokinetic

ABSTRACTThe relatively short half-lives of most β-lactams suggest that continuous infusion of these time-dependent antimicrobials may be favorable compared to short-term infusion. Nevertheless, only limited solid-tissue pharmacokinetic data are available to support this theory. In this study, we randomly assigned 12 pigs to receive cefuroxime as either a short-term or continuous infusion. Measurements of cefuroxime were obtained every 30 min in plasma, subcutaneous tissue, and bone. For the measurements in solid tissues, microdialysis was applied. A two-compartment population model was fitted separately to the drug concentration data for the different tissues using a nonlinear mixed-effects regression model. Estimates of the pharmacokinetic parameters and time with concentrations above the MIC were derived using Monte Carlo simulations. Except for subcutaneous tissue in the short-term infusion group, the tissue penetration was incomplete for all tissues. For short-term infusion, the tissue penetration ratios were 0.97 (95% confidence interval [CI], 0.67 to 1.39), 0.61 (95% CI, 0.51 to 0.73), and 0.45 (95% CI, 0.36 to 0.56) for subcutaneous tissue, cancellous bone, and cortical bone, respectively. For continuous infusion, they were 0.53 (95% CI, 0.33 to 0.84), 0.38 (95% CI, 0.23 to 0.57), and 0.27 (95% CI, 0.13 to 0.48) for the same tissues, respectively. The absolute areas under the concentration-time curve were also lower in the continuous infusion group. Nevertheless, a significantly longer time with concentrations above the MIC was found for continuous infusion up until MICs of 4, 2, 2, and 0.5 μg/ml for plasma and the same three tissues mentioned above, respectively. For drugs with a short half-life, like cefuroxime, continuous infusion seems to be favorable compared to short-term infusion; however, incomplete tissue penetration and high MIC strains may jeopardize the continuous infusion approach.

scholarly journals Comparative Assessment of Tedizolid Pharmacokinetics and Tissue Penetration between Diabetic Patients with Wound Infections and Healthy Volunteers via In Vivo Microdialysis

2017 ◽  
Vol 62 (1) ◽  
Author(s):  
Sean M. Stainton ◽  
Marguerite L. Monogue ◽  
Arlinda Baummer-Carr ◽  
Ashley K. Shepard ◽  
James F. Nugent ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Subcutaneous Tissue ◽  
Extracellular Fluid ◽  
Pharmacokinetic Parameters ◽  
Diabetic Patients ◽  
Tissue Penetration ◽  
Time Curve ◽  
Dosing Interval ◽  
Concentration Time

ABSTRACT Herein, we present pharmacokinetic and tissue penetration data for oral tedizolid in hospitalized patients with diabetic foot infections (DFI) compared with healthy volunteers. Participants received oral tedizolid phosphate 200 mg every 24 h for 3 doses to achieve steady state. A microdialysis catheter was inserted into the subcutaneous tissue near the margin of the wound for patients or into thigh tissue of volunteers. Following the third dose, 12 blood and 14 dialysate fluid samples were collected over 24 h to characterize tedizolid concentrations in plasma and interstitial extracellular fluid of soft tissue. Mean ± standard deviation (SD) tedizolid pharmacokinetic parameters in plasma for patients compared with volunteers, respectively, were as follows: maximum concentration (C max), 1.5 ± 0.5 versus 2.7 ± 1.1 mg/liter (P = 0.005); time to C max (T max) (median [range]), 5.9 (1.2 to 8.0) versus 2.5 (2.0 to 3.0 h) (P = 0.003); half-life (t1/2), 9.1 ± 3.6 versus 8.9 ± 2.2 h (P = 0.932); and plasma area under the concentration-time curve for the dosing interval (AUC p ), 18.5 ± 9.7 versus 28.7 ± 9.6 mg · h/liter (P = 0.004). The tissue area under the concentration-time curve (AUC t ) for the dosing interval was 3.4 ± 1.5 versus 5.2 ± 1.6 mg · h/liter (P = 0.075). Tissue penetration median (range) was 1.1 (0.3 to 1.6) versus 0.8 (0.7 to 1.0) (P = 0.351). Despite lower plasma C max and delayed T max values for patients with DFI relative to healthy volunteers, the penetration into and exposure to tissue were similar. Based on available pharmacodynamic thresholds for tedizolid, the plasma and tissue exposures using the oral 200 mg once-daily regimen are suitable for further study in treatment of DFI.

scholarly journals Pharmacokinetics and Tissue Penetration of Ceftolozane-Tazobactam in Diabetic Patients with Lower Limb Infections and Healthy Adult Volunteers

2017 ◽  
Vol 61 (12) ◽  
Author(s):  
Marguerite L. Monogue ◽  
Sean M. Stainton ◽  
Arlinda Baummer-Carr ◽  
Ashley K. Shepard ◽  
James F. Nugent ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Subcutaneous Tissue ◽  
Free Drug ◽  
Free Time ◽  
Pharmacokinetic Parameters ◽  
Diabetic Patients ◽  
Total Plasma ◽  
Tissue Penetration ◽  
Gram Negative ◽  
Time Zero

ABSTRACT Ceftolozane-tazobactam displays potent activity against Gram-negative bacteria that can cause diabetic foot infections (DFI), making it an attractive treatment option when few alternatives exist. The pharmacokinetics and tissue penetration of ceftolozane-tazobactam at 1.5 g every 8 h (q8h) in patients (n = 10) with DFI were compared with those in healthy volunteers (n = 6) using in vivo microdialysis. In the patient participants, the median values of the pharmacokinetic parameters for ceftolozane in total plasma were as follows: maximum concentration (C max), 55.2 μg/ml (range, 40.9 to 169.3 μg/ml); half-life (t 1/2), 3.5 h (range, 2.3 to 4.7 h); and area under the concentration-time curve (AUC) from time zero to 8 h (AUC0–8), 191.6 μg · h/ml (range, 147.1 to 286.6 μg · h/ml). The median AUC for tissue (AUCtissue; where AUCtissue was the AUC0–8 for tissue for ceftolozane)/AUC for plasma for each antibiotic corrected by the fraction of free drug (fAUCplasma) was 0.75 (range, 0.35 to 1.00), resulting in a mean free time above 4 μg/ml (the Pseudomonas aeruginosa susceptibility breakpoint) in tissue of 99.8% (range, 87.5 to 100%). In the patient participants, the median values of the pharmacokinetic parameters for tazobactam in total plasma were as follows: C max, 14.2 μg/ml (range, 7.6 to 64.2 μg/ml); t 1/2, 2.0 h (range, 0.7 to 2.4 h); and AUC0–8, 27.1 μg · h/ml (range, 15.0 to 70.0 μg · h/ml). The AUCtissue (where AUCtissue was the AUC from time zero to the time of the last measureable concentration in tissue for tazobactam)/fAUCplasma for tazobactam was 1.18 (range, 0.54 to 1.44). In the healthy volunteers, the median values of the pharmacokinetic parameters for ceftolozane in total plasma were as follows: C max, 91.5 μg/ml (range, 65.7 to 110.7 μg/ml); t 1/2, 1.9 h (range, 1.6 to 2.1 h); and AUC0–8, 191.3 μg · h/ml (range, 118.1 to 274.3 μg · h/ml). The median AUCtissue/fAUCplasma was 0.87 (range, 0.54 to 2.20), resulting in a mean free time above 4 μg/ml in tissue of 93.8% (range, 87.5 to 100%). In the healthy volunteers, the median values of the pharmacokinetic parameters for tazobactam in total plasma were as follows: C max, 17.5 μg/ml (range, 15.4 to 27.3 μg/ml); t 1/2, 0.7 h (range, 0.6 to 0.8 h); and AUC0–8, 22.2 μg · h/ml (range, 19.2 to 36.4 μg · h/ml). The AUCtissue/fAUCplasma for tazobactam was 0.85 (range, 0.63 to 2.10). Both ceftolozane and tazobactam penetrated into subcutaneous tissue with exposures similar to those of free drug in plasma in both patients with DFI and healthy volunteers. These data suggest that ceftolozane-tazobactam at 1.5 g q8h can achieve the optimal exposure with activity against susceptible Gram-negative pathogens in the tissue of patients with DFI. (This study has been registered at ClinicalTrials.gov under identifier NCT02620774.)

scholarly journals Indinavir Pharmacokinetics and Parmacodynamics in Children with Human Immunodeficiency Virus Infection

2000 ◽  
Vol 44 (3) ◽  
pp. 752-755 ◽  
Author(s):  
Giorgio Gatti ◽  
Alessandra Vigano' ◽  
Natascia Sala ◽  
Stefano Vella ◽  
Matteo Bassetti ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Dosage Regimen ◽  
Renal Toxicity ◽  
Significant Negative Correlation ◽  
Pharmacokinetic Parameters ◽  
Pharmacokinetic Data ◽  
Time Curve ◽  
Number Of Patients ◽  
Immunodeficiency Virus ◽  
The Difference

ABSTRACT The indinavir dosage regimen currently used for human immunodeficiency virus (HIV)-infected children is not based on pharmacokinetic data obtained in the target patient population. The purpose of our study was to characterize indinavir pharmacokinetics and pharmacodynamics in HIV-infected children. Eleven children (age range, 9.0 to 13.6 years; weight range, 21.7 to 56.0 kg) receiving indinavir (500 mg/m2 every 8 h) in combination with lamivudine and stavudine were studied. The correlation of indinavir pharmacokinetic parameters and demographic parameters was evaluated. Also, the pharmacodynamic relationship between parameters of indinavir exposure and parameters of renal toxicity and immunologic recovery was studied. The area under the indinavir concentration-time curve (AUC) and patient body surface area (BSA) showed a significant negative correlation (r = 0.73; P = 0.012). Patients with smaller BSA had excessive indinavir AUC compared to adults. On the other hand, the median minimum drug concentration in plasma (C min) was lower than that reported for adults. The maximum indinavir concentration in serum was higher in patients with renal toxicity (5 out of 11 children), but the difference was not statistically significant (15.3 ± 8.2 versus 9.8 ± 4.4 mg/liter; P = 0.19). There was a trend toward higher immunologic efficacy in patients with greater indinavir exposure: the time-averaged AUC of the percentage of CD4+ lymphocytes over the baseline value for patients with indinavir C min > 95% inhibitory concentration (IC95) was higher than in patients withC min < IC95(P = 0.068). Our study suggests that a dose reduction may be appropriate for children with small BSA and that a 6-h dosage regimen may be indicated for a substantial percentage of patients. Due to the low number of patients enrolled in this study, our results should be confirmed by a larger study.

Local Vancomycin Concentrations after Intra-articular Injection into the Knee Joint: An Experimental Porcine Study

2019 ◽  
Author(s):  
Mats Bue ◽  
Maja B. Thomassen ◽  
Ole H. Larsen ◽  
Andrea R. Jørgensen ◽  
Maiken Stilling ◽  
...  
Keyword(s):  
Synovial Fluid ◽  
Knee Joint ◽  
Drug Concentration ◽  
Subcutaneous Tissue ◽  
Venous Blood ◽  
Plasma Concentrations ◽  
Systemic Circulation ◽  
Pharmacokinetic Parameters ◽  
Time Curve ◽  
Prosthetic Joint Infections

AbstractIntra-articular injection of vancomycin may be an important antimicrobial prophylactic supplement to systemic administration in the prevention of prosthetic joint infections. In eight female pigs, 500 mg of diluted vancomycin was given by intra-articular injection into the knee joint. Microdialysis was used for dense sampling of vancomycin concentrations over 12 hours in the synovial fluid of the knee joint, and in the adjacent femoral and tibial cancellous bone and subcutaneous tissue. Venous blood samples were obtained as reference. The mean (standard deviation [SD]) peak drug concentration of vancomycin in the synovial fluid of the knee joint was 5,277 (5,668) μg/mL. Only one pig failed to reach a peak drug concentration above 1,000 μg/mL. The concentration remained high throughout the sampling interval with a mean (SD) concentration of 337 (259) μg/mL after 690 minutes. For all extraarticular compartments, the pharmacokinetic parameters (area under the concentration time-curve, peak drug concentration, and time to peak drug concentration) were comparable. The highest extraarticular mean (SD) peak drug concentration of 4.4 (2.3) μg/mL was found in subcutaneous tissue. An intra-articular injection of 500 mg diluted vancomycin was found to provide significant prophylactic mean concentrations for at least 12 hours in the synovial fluid of the knee joint. Correspondingly, the adjacent tissue and plasma concentrations were low but remained stable, signifying low risk of systemic toxic side effects and a slow release or uptake from the synovium to the systemic circulation.

scholarly journals Pharmacokinetics of Isoniazid in Low-Birth-Weight and Premature Infants

2014 ◽  
Vol 58 (4) ◽  
pp. 2229-2234 ◽  
Author(s):  
A. Bekker ◽  
H. S. Schaaf ◽  
H. I. Seifart ◽  
H. R. Draper ◽  
C. J. Werely ◽  
...  
Keyword(s):  
Birth Weight ◽  
Low Birth Weight ◽  
Blood Plasma ◽  
Plasma Concentrations ◽  
Safety Data ◽  
Preventive Therapy ◽  
Interquartile Range ◽  
Pharmacokinetic Parameters ◽  
Pharmacokinetic Data ◽  
Time Curve

ABSTRACTIsoniazid (INH) is recommended for use as posttuberculosis exposure preventive therapy in children. However, no pharmacokinetic data are available for INH treatment in low-birth-weight (LBW) infants, who undergo substantial developmental and physiological changes. Our objectives in this study were to determine the pharmacokinetic parameters of INH at a dose of 10 mg/kg of body weight/day and to define its pharmacokinetics relative to the arylamineN-acetyltransferase-2 (NAT2) genotype. An intensive prospective pharmacokinetic sampling study was conducted at Tygerberg Children's Hospital, South Africa, in which we measured INH blood plasma concentrations at 2, 3, 4 and 5 h postdose. Twenty LBW infants (14 male, 16 exposed to HIV) were studied. The median birth weight was 1,575 g (interquartile range, 1,190 to 2,035 g) and the median gestational age was 35 weeks (interquartile range, 34 to 38 weeks). TheNAT2acetylation statuses of the infants were homozygous slow (SS) (5 infants), heterozygous intermediate (FS) (11 infants), and homozygous fast (FF) (4 infants). Using a noncompartmental analysis approach, the median maximum drug concentration in blood serum (Cmax) was 5.63 μg/ml, the time after drug administration to reachCmaxTmax) was 2 h, the area under the concentration-time curve from 2 to 5 h (AUC2–5) was 13.56 μg · h/ml, the half-life (t1/2) was 4.69 h, and the elimination constant rate (kel) was 0.15 h−1. The alanine aminotransferase levels were normal, apart from 2 isolated values at two and three times above the normal levels. Only the three-times-elevated value was repeated at 6 months and normalized. All LBW infants achieved target INH blood plasma concentrations comparable to the adult values. Reduced elimination was observed in smaller and younger infants and in slow acetylators, cautioning against higher doses. The safety data, although limited, were reassuring. More data, however, are required for newborn infants.

scholarly journals Modest but Variable Effect of Rifampin on Steady-State Plasma Pharmacokinetics of Efavirenz in Healthy African-American and Caucasian Volunteers

2011 ◽  
Vol 55 (7) ◽  
pp. 3527-3533 ◽  
Author(s):  
Awewura Kwara ◽  
Karen T. Tashima ◽  
Julie B. Dumond ◽  
Pamela Poethke ◽  
Jaclyn Kurpewski ◽  
...  
Keyword(s):  
Body Weight ◽  
High Performance ◽  
Geometric Mean ◽  
Pharmacokinetic Analysis ◽  
Pharmacokinetic Parameters ◽  
Pharmacokinetic Data ◽  
Time Curve ◽  
Variable Effect ◽  
Coefficients Of Variation ◽  
Tuberculosis Therapy

ABSTRACTEfavirenz-based antiretroviral regimen is preferred during rifampin-containing tuberculosis therapy. However, current pharmacokinetic data are insufficient to guide optimized concurrent dosing. This study aimed to better characterize the effects of rifampin on efavirenz pharmacokinetics. Subjects were randomized to receive 600 mg efavirenz/day or 600 mg efavirenz with 600 mg rifampin/day for 8 days, with plasma samples collected for pharmacokinetic analysis over 24 h on day 8. Treatments were then crossed over after at least a 2-week washout period, and procedures were repeated. Efavirenz concentrations were determined by high-performance liquid chromatography (HPLC), and pharmacokinetic parameters were estimated by noncompartmental analysis. Efavirenz pharmacokinetic differences between treatment periods were evaluated by pairedttest. The coefficients of variation in efavirenz plasma AUC0-24(area under the concentration-time curve from 0 to 24 h) were 50% and 56% in the absence and presence of rifampin, respectively. Of the 11 evaluable subjects (6 white, 5 black; 6 women, 5 men), the geometric mean AUC0-24ratio on/off rifampin (90% confidence interval) was 0.82 (0.72, 0.92), with individual AUC0-24ratios varying from 0.55 to 1.18. Five subjects had a 24-hour efavirenz concentration (C24) of <1,000 ng/ml on rifampin. They were more likely to have received a lower dose in milligrams/kilogram of body weight and to have lower efavirenz AUC0-24values in the basal state. Although rifampin resulted in a modest reduction in efavirenz plasma exposure in subjects as a whole, there was high variability in responses between subjects, suggesting that efavirenz dose adjustment with rifampin may need to be individualized. Body weight and genetic factors will be important covariates in dosing algorithms.

scholarly journals Pharmacokinetic Study of Tenofovir Disoproxil Fumarate Combined with Rifampin in Healthy Volunteers

2005 ◽  
Vol 49 (2) ◽  
pp. 680-684 ◽  
Author(s):  
J. A. H. Droste ◽  
C. P. W. G. M. Verweij-van Wissen ◽  
B. P. Kearney ◽  
R. Buffels ◽  
P. J. vanHorssen ◽  
...  
Keyword(s):  
Tenofovir Disoproxil Fumarate ◽  
Multiple Dose ◽  
Pharmacokinetic Parameters ◽  
Pharmacokinetic Data ◽  
Open Label ◽  
Time Curve ◽  
Simultaneous Treatment ◽  
Minimum Concentration ◽  
Period 2 ◽  
Tenofovir Df

ABSTRACT Tenofovir disoproxil fumarate (tenofovir DF) was studied in combination with rifampin in 24 healthy subjects in a multiple-dose, open-label, single-group, two-period study. All subjects were given tenofovir DF at 300 mg once a day (QD) from days 1 to 10 (period 1). From days 11 to 20 the subjects received tenofovir DF at 300 mg combined with rifampin at 600 mg QD (period 2). The multiple-dose pharmacokinetics of tenofovir (day 10 and 20) and rifampin (day 20) were assessed. The drug-related adverse events (AEs) experienced during this study were mostly mild. Only one grade 3 AE possibly or probably related to the treatment (raised liver enzyme levels) occurred during period 2; the subject was withdrawn from the study. Pharmacokinetic data for 23 subjects were thus evaluable. Point estimates for the mean ratios of tenofovir with rifampin versus tenofovir alone for the area under the concentration-time curve from time zero to 24 h (AUC0-24), the maximum concentration of drug in plasma (C max), and the minimum concentration of drug in plasma (C min) were 0.88, 0.84, and 0.85, respectively. The 90% classical confidence intervals for AUC0-24, C max, and C min were 0.84 to 0.92, 0.78 to 0.90, and 0.80 to 0.91, respectively, thus suggesting pharmacokinetic equivalence. Similarly, coadministration of rifampin and tenofovir DF did not result in changes in the values of the tenofovir pharmacokinetic parameters. For rifampin, the values of the pharmacokinetic parameters found in this study were comparable to those found in the literature, indicating that tenofovir DF has no effect on the pharmacokinetics of rifampin. In conclusion, adaptation of either the rifampin or the tenofovir DF dose for the simultaneous treatment of tuberculosis and human immunodeficiency virus (HIV) infection in HIV-infected patients is probably not required.

scholarly journals Effect of Telaprevir on the Pharmacokinetics of Buprenorphine in Volunteers on Stable Buprenorphine/Naloxone Maintenance Therapy

2012 ◽  
Vol 56 (7) ◽  
pp. 3641-3647 ◽  
Author(s):  
Xia Luo ◽  
Jose Trevejo ◽  
Rolf P. G. van Heeswijk ◽  
Frances Smith ◽  
Varun Garg
Keyword(s):  
Maintenance Therapy ◽  
Least Squares ◽  
Confidence Intervals ◽  
Pharmacokinetic Parameters ◽  
Pharmacokinetic Data ◽  
Open Label ◽  
Serious Adverse Events ◽  
Time Curve ◽  
Symptom Frequency ◽  
Single Sequence

ABSTRACTThis was an open-label, single-sequence trial in hepatitis C virus-negative volunteers on stable, individualized, buprenorphine maintenance therapy. Telaprevir at 750 mg every 8 h was coadministered with buprenorphine/naloxone (4:1 ratio as sublingual tablets) for 7 days with food. Pharmacokinetic profiles of buprenorphine, norbuprenorphine, and naloxone were measured over the 24-hour dosing interval on day −1 (buprenorphine/naloxone alone, reference) and day 7 of telaprevir coadministration (test). Geometric least-squares mean ratios and associated 90% confidence intervals of treatment ratios (test/reference) were calculated using log-transformed pharmacokinetic parameters. Opioid withdrawal symptoms were evaluated throughout the study (via questionnaires and pupillometry). Pharmacokinetic data were available for 14 and 13 volunteers on day −1 and day 7, respectively. The area under the concentration-time curve (AUC) for buprenorphine was unchanged and the maximum concentration of drug in serum (Cmax) for buprenorphine,Cmaxand AUC for norbuprenorphine, andCmaxnaxolone were modestly decreased during coadministration with telaprevir. Geometric least-squares mean ratios (90% confidence intervals) for buprenorphine were 0.80 (0.69, 0.93) for theCmaxand 0.96 (0.84, 1.10) for the AUC from 0 to 24 h (AUC0–24); for norbuprenorphine, values were 0.85 (0.66, 1.09) forCmaxand 0.91 (0.71, 1.16) for AUC0–24; for naloxone, theCmaxwas 0.84 (0.62, 1.13). Coadministration of telaprevir did not increase withdrawal symptom frequency, and there were no serious adverse events reported during or after completion of telaprevir coadministration. Results suggest dose adjustment may not be necessary when telaprevir and buprenorphine/naloxone are coadministered.

scholarly journals Tissue Penetration and Pharmacokinetics of Tigecycline in Diabetic Patients with Chronic Wound Infections Described by Using In Vivo Microdialysis

2010 ◽  
Vol 54 (12) ◽  
pp. 5209-5213 ◽  
Author(s):  
Catharine C. Bulik ◽  
Dora E. Wiskirchen ◽  
Ashley Shepard ◽  
Christina A. Sutherland ◽  
Joseph L. Kuti ◽  
...  
Keyword(s):  
Steady State ◽  
Protein Binding ◽  
Subcutaneous Tissue ◽  
Diabetic Patients ◽  
Tissue Penetration ◽  
Tissue Concentrations ◽  
Time Curve ◽  
The Mean

ABSTRACT Tissue penetration of systemic antibiotics is an important consideration for positive outcomes in diabetic patients. Herein we describe the exposure profile and penetration of tigecycline in the interstitial fluid of wound margins versus that of uninfected thigh tissue in 8 adult diabetic patients intravenously (IV) administered 100 mg and then 50 mg of tigecycline twice daily for 3 to 5 doses. Prior to administration of the first dose, 2 microdialysis catheters were inserted into the subcutaneous tissue, the first within 10 cm of the wound margin and the second in the thigh of the same extremity. Samples for determination of plasma and tissue concentrations were simultaneously collected over 12 h under steady-state conditions. Tissue concentrations were corrected for percent in vivo recovery by the retrodialysis technique. Plasma samples were also collected for determination of protein binding at 1, 6, and 12 h postdose for each patient. Protein binding data were corrected using a fitted polynomial equation. The mean patient weight was 95.1 kg (range, 63.6 to 149.2 kg), the mean patient age was 63.5 ± 9.4 years, and 75% of the patients were males. The mean values for the plasma, thigh, and wound free area under the concentration-time curve from 0 to 24 h (fAUC0-24) were 2.65 ± 0.33, 2.52 ± 1.15, and 2.60 ± 1.02 μg·h/ml, respectively. Protein binding was nonlinear, with the percentage of free drug increasing with decreasing serum concentrations. Exposure values for thigh tissue and wound tissue were similar (P = 0.986). Mean steady-state tissue concentrations for the thigh and wound were similar at 0.12 ± 0.02 μg/ml, and clearance from the tissues appeared similar to that from plasma. Tissue penetration ratios (tissue fAUC/plasma fAUC) were 99% in the thigh and 100% in the wound (P = 0.964). Tigecycline penetrated equally well into wound and uninfected tissue of the same extremity.

scholarly journals Phase Ib Trial To Evaluate the Safety and Pharmacokinetics of Multiple Ascending Doses of Filociclovir (MBX-400, Cyclopropavir) in Healthy Volunteers

2019 ◽  
Vol 63 (9) ◽  
Author(s):  
Nadine G. Rouphael ◽  
Selwyn J. Hurwitz ◽  
Mari Hart ◽  
Allison Beck ◽  
Evan J. Anderson ◽  
...  
Keyword(s):  
Adverse Events ◽  
Clinical Laboratory ◽  
Subcutaneous Tissue ◽  
Phase 1 ◽  
Plasma Concentrations ◽  
Pharmacokinetic Parameters ◽  
Plasma Exposure ◽  
Serious Adverse Events ◽  
Double Blind ◽  
Time Curve

ABSTRACT Filociclovir (MBX-400, cyclopropavir) is an antiviral agent with activity against cytomegalovirus (CMV). A phase 1, double-blind, randomized, placebo-controlled (3:1 ratio), single-center, multiple-ascending-dose trial was conducted to assess the safety, tolerability, and pharmacokinetics of filociclovir. Filociclovir (n = 18) or placebo (n = 6) was administered as a daily oral dose (100 mg, 350 mg, or 750 mg) for 7 days to normal healthy adults (ages, 25 to 65 years) who were monitored for 22 days. Safety assessments included clinical, laboratory, and electrocardiogram monitoring. Plasma and urine samplings were used to determine pharmacokinetic parameters. All study product-related adverse events were mild, most commonly gastrointestinal (17%), nervous system (11%), and skin and subcutaneous tissue (11%) disorders. One subject had reversible grade 3 elevation in serum creatinine and bilirubin, which was associated with an ∼1-log increase in plasma filociclovir exposure compared to levels for other subjects in the same (750-mg) cohort. No other serious adverse events were observed. Plasma exposures (area under the concentration-time curve from 0 to 24 h [AUC0–24]) on days 1 and 7 were similar, suggesting negligible dose accumulation. There was a sublinear increase in plasma exposure with dose, which plateaued at the daily dose of 350 mg. The amount of filociclovir recovered in the urine remained proportional to plasma exposure (AUC). Doses as low as 100 mg achieved plasma concentrations sufficient to inhibit CMV in vitro. (This study has been registered at ClinicalTrials.gov under identifier NCT02454699.)

Sign in / Sign up

Export Citation Format

Share Document