scholarly journals Rational dosing of HCQ for COVID-19_pre-print

2020 ◽  
Author(s):  
Kevin Downes ◽  
Kathleen Chiotos ◽  
Julie Fitzgerald ◽  
Marc H Scheetz ◽  
Athena F. Zuppa
Keyword(s):  
Plasma Concentrations ◽  
Safety Data ◽  
Loading Dose ◽  
Maximal Concentration ◽  
In Vitro Activity ◽  
Time Curve ◽  
First Order ◽  
Concentration Time ◽  
Autoimmune Conditions

Background: Hydroxychloroquine (HCQ) has in vitro activity against SARS-CoV-2. However, datato inform optimal human dosing are limited.Methods: We conducted Monte Carlo simulations of HCQ sulfate using a published populationpharmacokinetic model. The model informing our simulations described a 2-compartmentlinear model with first-order absorption with a lag, derived from plasma HCQ concentrationdata from 22 healthy adults and 69 patients with malaria. Using the final PK model, we performed 1000 simulations for the plasma concentrations of HCQ sulfate based on various approved dosages (i.e. acute malaria, autoimmune conditions) and proposed dosing regimensfor treatment of COVID-19. The results of simulations were used to derive the area under the concentration-time curve (AUC), maximal concentration, and time to maximal concentration for each evaluated regimen.Results: The use of a loading dose, as with acute malaria dosing, resulted in rapid achievementof maximal concentrations early in the treatment course, which were maintained with dailydosing thereafter. The use of once or twice daily doses without a loading dose led to slowlyincreasing plasma concentrations through day 10. Simulated regimens that employed an 800mg loading dose for adults (13 mg/kg for children) followed by 400 mg at 6 or 12 hours (6.5mg/kg for children) achieved the greatest AUC0-24.Conclusions: Based on our findings, along with established safety data from malarial studies,we believe that approved dosing for treatment acute malaria is the most reasonable and safestapproach if HCQ will be used to treat COVID-19.

scholarly journals Randomized, Double-Blind, Placebo-Controlled Studies of the Safety and Pharmacokinetics of Single and Multiple Ascending Doses of Eravacycline

2018 ◽  
Vol 62 (11) ◽  
Author(s):  
Joseph V. Newman ◽  
Jian Zhou ◽  
Sergey Izmailyan ◽  
Larry Tsai
Keyword(s):  
Healthy Subjects ◽  
Plasma Concentrations ◽  
Multidrug Resistant ◽  
Maximum Plasma ◽  
Double Blind ◽  
Time Curve ◽  
Concentration Time ◽  
Dosing Regimens ◽  
Aerobic And Anaerobic

ABSTRACT Eravacycline is a novel, fully synthetic fluorocycline antibiotic with in vitro activity against aerobic and anaerobic Gram-positive and Gram-negative pathogens, including multidrug-resistant (MDR) bacteria. The pharmacokinetics (PK), urinary excretion, and safety/tolerability of intravenous (i.v.) eravacycline were evaluated in single- and multiple-ascending-dose studies. Healthy subjects received single i.v. doses of 0.1 to 3 mg/kg of body weight or 10 days of treatment with 0.5 or 1.5 mg/kg every 24 h (q24h) over 30 min, 1.5 mg/kg q24h over 60 min, or 1 mg/kg q12h over 60 min. After single doses, total exposure (the area under the plasma concentration-time curve [AUC]) and the maximum plasma concentrations (Cmax) of eravacycline increased in an approximately dose-proportional manner. After multiple doses, steady state was achieved within 5 to 7 days. Accumulation ranged from approximately 7% to 38% with the q24h dosing regimens and was 45% with 1 mg/kg q12h. Eravacycline was generally well tolerated, with dose-related nausea, infusion site effects, and superficial phlebitis that were mild or moderate occurring. These results provide support for the 1-mg/kg q12h regimen used in clinical studies of eravacycline.

scholarly journals 1326. Vancomycin Area Under the Concentration-Time Curve (AUC) Estimation Using a Bayesian Approach Versus First-Order Pharmacokinetic Equations: A Pilot Study

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S673-S673
Author(s):  
Jeffrey Pearson ◽  
Yazed S Alsowaida ◽  
B S Pharm ◽  
David W Kubiak ◽  
Mary P Kovacevic ◽  
...  
Keyword(s):  
Pilot Study ◽  
Median Time ◽  
Bayesian Modeling ◽  
Surgical Prophylaxis ◽  
Time Curve ◽  
Team Members ◽  
First Order ◽  
Concentration Time ◽  
Study Team ◽  
Auc Estimation

Abstract Background Current guidelines endorse area under the concentration-time curve (AUC)-based monitoring over trough-only monitoring for systemic vancomycin. Vancomycin AUC can be estimated using either Bayesian modeling software or first-order pharmacokinetic (PK) calculations. The objective of this pilot study was to evaluate and compare the efficiency and feasibility of these two approaches for calculating the estimated vancomycin AUC. Methods A single-center crossover study was conducted in four medical/surgical units at Brigham and Women’s Hospital over a 3-month time period. All adult patients who received vancomycin were included. Patients were excluded if they were receiving vancomycin for surgical prophylaxis, were on hemodialysis, if vancomycin was being dosed by level, or if vancomycin levels were never drawn. The primary endpoint was the amount of time study team members spent calculating the estimated AUC and determining regimen adjustments with Bayesian modeling compared to first-order PK calculations. Secondary endpoints included the number of vancomycin levels drawn and the percent of those drawn that were usable for AUC calculations. Results One hundred twenty-four patients received vancomycin during the study, of whom 47 met inclusion criteria. The most likely reasons for exclusion were receiving vancomycin for surgical prophylaxis (n=40) or never having vancomycin levels drawn (n=32). The median time taken to assess levels in the Bayesian arm was 9.3 minutes [interquartile range (IQR) 7.8-12.4] versus 6.8 minutes (IQR 4.8-8.0) in the 2-level PK arm (p=0.004). However, if Bayesian software is integrated into the electronic health record (EHR), the median time to assess levels was 3.8 minutes (IQR 2.3-6.8, p=0.019). In the Bayesian arm, 30 of 34 vancomycin levels (88.2%) were usable for AUC calculations, compared to 28 of 58 (48.3%) in the 2-level PK arm. Conclusion With EHR integration, the use of Bayesian software to calculate the AUC was more efficient than first-order PK calculations. Additionally, vancomycin levels were more likely to be usable in the Bayesian arm, thereby avoiding delays in estimating the vancomycin AUC. Disclosures All Authors: No reported disclosures

scholarly journals Pharmacological Basis of CD101 Efficacy: Exposure Shape Matters

2017 ◽  
Vol 61 (11) ◽  
Author(s):  
Elizabeth A. Lakota ◽  
Justin C. Bader ◽  
Voon Ong ◽  
Ken Bartizal ◽  
Lynn Miesel ◽  
...  
Keyword(s):  
Time Course ◽  
Fungicidal Activity ◽  
Control Group ◽  
Time Curve ◽  
Content Type ◽  
Treatment Groups ◽  
Concentration Time ◽  
Treatment Control Group ◽  
Pharmacological Basis

ABSTRACT CD101 is a novel echinocandin with concentration-dependent fungicidal activity in vitro and a long half-life (∼133 h in humans, ∼70 to 80 h in mice). Given these characteristics, it is likely that the shape of the CD101 exposure (i.e., the time course of CD101 concentrations) influences efficacy. To test this hypothesis, doses which produce the same total area under the concentration-time curve (AUC) were administered to groups of neutropenic ICR mice infected with Candida albicans R303 using three different schedules. A total CD101 dose of 2 mg/kg was administered as a single intravenous (i.v.) dose or in equal divided doses of either 1 mg/kg twice weekly or 0.29 mg/kg/day over 7 days. The studies were performed using a murine disseminated candidiasis model. Animals were euthanized at 168 h following the start of treatment. Fungi grew well in the no-treatment control group and showed variable changes in fungal density in the treatment groups. When the CD101 AUC from 0 to 168 h (AUC0–168) was administered as a single dose, a >2 log10 CFU reduction from the baseline at 168 h was observed. When twice-weekly and daily regimens with similar AUC values were administered, net fungal stasis and a >1 log10 CFU increase from the baseline were observed, respectively. These data support the hypothesis that the shape of the CD101 AUC influences efficacy. Thus, CD101 administered once per week demonstrated a greater degree of fungal killing than the same dose divided into twice-weekly or daily regimens.

scholarly journals Pharmacokinetics of intramuscularly administered aminosidine in healthy subjects.

1997 ◽  
Vol 41 (5) ◽  
pp. 982-986 ◽  
Author(s):  
T P Kanyok ◽  
A D Killian ◽  
K A Rodvold ◽  
L H Danziger
Keyword(s):  
Healthy Subjects ◽  
Randomized Clinical Trials ◽  
Elimination Rate ◽  
Pharmacokinetic Parameters ◽  
Multiple Drug ◽  
Time Data ◽  
Time Curve ◽  
First Order ◽  
Significant Difference

Aminosidine is an older, broad-spectrum aminoglycoside antibiotic that has been shown to be effective in in vitro and animal models against multiple-drug-resistant tuberculosis and the Mycobacterium avium complex. The objective of this randomized, parallel trial was to characterize the single-dose pharmacokinetics of aminosidine sulfate in healthy subjects (eight males, eight females). Sixteen adults (mean [+/- standard deviation] age, 27.6 +/- 5.6 years) were randomly allocated to receive a single, intramuscular aminosidine sulfate injection at a dose of 12 or 15 mg/kg of body weight. Serial plasma and urine samples were collected over a 24-h period and used to determine aminosidine concentrations by high-performance liquid chromatographic assay. A one-compartment model with first-order input, first-order output, and a lag time (Tlag) and with a weighting factor of 1/y2 best described the data. Compartmental and noncompartmental pharmacokinetic parameters were estimated with the microcomputer program WinNonlin. One subject was not included (15-mg/kg group) because of the lack of sampling time data. On average, subjects attained peak concentrations of 22.4 +/- 3.2 microg/ml at 1.34 +/- 0.45 h. All subjects had plasma aminosidine concentrations below 2 microg/ml at 12 h, and all but two subjects (one in each dosing group) had undetectable plasma aminosidine concentrations at 24 h. The dose-adjusted area under the concentration-time curve from 0 h to infinity of aminosidine was identical for the 12- and 15-mg/kg groups (9.29 +/- 1.5 versus 9.29 +/- 2.2 microg x h/ml per mg/kg; P = 0.998). Similarly, no significant differences (P > 0.05) were observed between dosing groups for peak aminosidine concentration in plasma, time to peak aminosidine concentration in plasma, Tlag, apparent clearance, renal clearance, elimination rate constant, and elimination half-life. A significant difference was observed for the volume of distribution (0.35 versus 0.41 liters/kg; P = 0.037) between the 12 and 15 mg/kg dosing groups. Now that comparable pharmacokinetic profiles between dosing groups have been demonstrated, therapeutic equivalency testing via in vitro pharmacokinetic and pharmacodynamic modelling and randomized clinical trials in humans should be conducted.

scholarly journals Pharmacokinetics of Ethambutol under Fasting Conditions, with Food, and with Antacids

1999 ◽  
Vol 43 (3) ◽  
pp. 568-572 ◽  
Author(s):  
Charles A. Peloquin ◽  
Amy E. Bulpitt ◽  
George S. Jaresko ◽  
Roger W. Jelliffe ◽  
James M. Childs ◽  
...  
Keyword(s):  
Maximum Concentration ◽  
Pharmacokinetic Model ◽  
Mass Spectrometry Data ◽  
Gas Chromatography Mass Spectrometry ◽  
High Fat ◽  
Time Curve ◽  
First Order ◽  
Concentration Time ◽  
Males And Females ◽  
Fat Meal

ABSTRACT Ethambutol (EMB) is the most frequent “fourth drug” used for the empiric treatment of Mycobacterium tuberculosis and a frequently used drug for infections caused by Mycobacterium avium complex. The pharmacokinetics of EMB in serum were studied with 14 healthy males and females in a randomized, four-period crossover study. Subjects ingested single doses of EMB of 25 mg/kg of body weight under fasting conditions twice, with a high-fat meal, and with aluminum-magnesium antacid. Serum was collected for 48 h and assayed by gas chromatography-mass spectrometry. Data were analyzed by noncompartmental methods and by a two-compartment pharmacokinetic model with zero-order absorption and first-order elimination. Both fasting conditions produced similar results: a mean (± standard deviation) EMB maximum concentration of drug in serum (C max) of 4.5 ± 1.0 μg/ml, time to maximum concentration of drug in serum (T max) of 2.5 ± 0.9 h, and area under the concentration-time curve from 0 h to infinity (AUC0–∞) of 28.9 ± 4.7 μg · h/ml. In the presence of antacids, subjects had a mean C maxof 3.3 ± 0.5 μg/ml, T max of 2.9 ± 1.2 h, and AUC0–∞ of 27.5 ± 5.9 μg · h/ml. In the presence of the Food and Drug Administration high-fat meal, subjects had a mean C max of 3.8 ± 0.8 μg/ml, T max of 3.2 ± 1.3 h, and AUC0–∞ of 29.6 ± 4.7 μg · h/ml. These reductions in C max, delays inT max, and modest reductions in AUC0–∞ can be avoided by giving EMB on an empty stomach whenever possible.

scholarly journals Development of a Physiologically Based Pharmacokinetic Model for Prediction of Ethanol Concentration-Time Profile in Different Organs

2020 ◽  
Author(s):  
Armin Sadighi ◽  
Lorenzo Leggio ◽  
Fatemeh Akhlaghi
Keyword(s):  
Pbpk Model ◽  
Organ Damage ◽  
Time Profile ◽  
Sensitivity Analyses ◽  
Pbpk Modeling ◽  
Time Curve ◽  
Physiologically Based Pharmacokinetic ◽  
Concentration Time ◽  
Physiologically Based

Abstract Aims A physiologically based pharmacokinetic (PBPK) modeling approach was used to simulate the concentration-time profile of ethanol (EtOH) in stomach, duodenum, plasma and other tissues upon consumption of beer and whiskey under fasted and fed conditions. Methods A full PBPK model was developed for EtOH using the advanced dissolution, absorption and metabolism (ADAM) model fully integrated into the Simcyp Simulator® 15 (Simcyp Ltd., Sheffield, UK). The prediction performance of the developed model was verified and the EtOH concentration-time profile in different organs was predicted. Results Simcyp simulation showed ≤ 2-fold difference in values of EtOH area under the concentration-time curve (AUC) in stomach and duodenum as compared to the observed values. Moreover, the simulated EtOH maximum concentration (Cmax), time to reach Cmax (Tmax) and AUC in plasma were comparable to the observed values. We showed that liver is exposed to the highest EtOH concentration, faster than other organs (Cmax = 839.50 mg/L and Tmax = 0.53 h), while brain exposure of EtOH (AUC = 1139.43 mg·h/L) is the highest among all other organs. Sensitivity analyses (SAs) showed direct proportion of EtOH rate and extent of absorption with administered EtOH dose and inverse relationship with gastric emptying time (GE) and steady-state volume of distribution (Vss). Conclusions The current PBPK model approach might help with designing in vitro experiments in the area of alcohol organ damage or alcohol-drug interaction studies.

Exposure to Retinoic Acids in Non-Pregnant Women Following High Vitamin A Intake with a Liver Meal

2005 ◽  
Vol 75 (3) ◽  
pp. 187-194 ◽  
Author(s):  
Hartmann ◽  
Brørs ◽  
Bock ◽  
Blomhoff ◽  
Bausch ◽  
...  
Keyword(s):  
Plasma Concentration ◽  
Vitamin A ◽  
Safety Concern ◽  
Peak Plasma ◽  
Plasma Concentrations ◽  
Pregnant Female ◽  
Time Curve ◽  
High Vitamin ◽  
Concentration Time ◽  
Plasma Concentration Time Curve

Animal liver is a rich source of vitamin A. Due to retinoic acid (RA) metabolites, vitamin A has a teratogenic potential and women are generally advised to avoid or to limit the consumption of liver during pregnancy. In a recent study in non-pregnant female volunteers following single and repeated doses of up to 30,000 IU/day of vitamin A as a supplement, the plasma concentration time curve of all-trans RA acid showed a diurnal-like profile. But, the overall exposure (AUC24h) remained essentially unaltered whereas AUC24h increased linearly with dose for 13-cis and 13-cis-4-oxo RA. The current study in non-pregnant female volunteers showed that a single high vitamin A intake with a liver meal (up to 120,000 IU) exhibited a similar diurnal-like plasma concentration time curve for all-trans RA and its overall exposure remained also unaltered, despite a temporary two-fold increase in peak plasma concentration. Concentrations of 13-cis and 13-cis-4-oxo RA increased several-fold after a liver meal, and exposure (AUC24h) increased three- to five-fold. Pooling our results with data in the literature revealed a linear relation between the mean AUC24h of 13-cis and 13-cis-4-oxo RA and vitamin A intake with liver. Metabolism to all-trans RA of vitamin A with liver seems not to be of safety concern. However, the observed increase of plasma concentrations and the dose-dependent increase in exposure to 13-cis and 13-cis-4-oxo RA support the current safety recommendations on vitamin A intake and suggest that women should be cautious regarding their consumption of liver-containing meals during pregnancy.

scholarly journals Development of a Population Pharmacokinetic Model for Parecoxib and Its Active Metabolite Valdecoxib after Parenteral Parecoxib Administration in Children

2012 ◽  
Vol 116 (5) ◽  
pp. 1124-1133 ◽  
Author(s):  
Bruce Hullett ◽  
Sam Salman ◽  
Sean J. O'Halloran ◽  
Deborah Peirce ◽  
Kylie Davies ◽  
...  
Keyword(s):  
Active Metabolite ◽  
Pharmacokinetic Model ◽  
Inhibitory Concentration ◽  
Prediction Interval ◽  
Cyclooxygenase 2 ◽  
Pharmacokinetic Parameters ◽  
Population Pharmacokinetic ◽  
Time Curve ◽  
Concentration Time

Background Parecoxib is a cyclooxygenase-2 selective inhibitor used in management of postoperative pain in adults. This study aimed to provide pediatric pharmacokinetic information for parecoxib and its active metabolite valdecoxib. Methods Thirty-eight children undergoing surgery received parecoxib (1 mg/kg IV to a maximum of 40 mg) at induction of anesthesia, and plasma samples were collected for drug measurement. Population pharmacokinetic parameters were estimated using nonlinear mixed effects modeling. Area under the valdecoxib concentration-time curve and time above cyclooxygenase-2 in vitro 50% inhibitory concentration for free valdecoxib were simulated. Results A three-compartment model best represented parecoxib disposition, whereas one compartment was adequate for valdecoxib. Age was linearly correlated with parecoxib clearance (5.0% increase/yr). There was a sigmoid relationship between age and both valdecoxib clearance and distribution volume. Time to 50% maturation was 87 weeks postmenstrual age for both. In simulations using allometric-based doses the 90% prediction interval of valdecoxib concentration-time curve in children 2-12.7 yr included the mean for adults given 40 mg parecoxib IV. Simulated free valdecoxib plasma concentration remained above the in vitro 50% inhibitory concentrations for more than 12 h. In children younger than 2 yr, a dose reduction is likely required due to ongoing metabolic maturation. Conclusions The final pharmacokinetic model gave a robust representation of parecoxib and valdecoxib disposition. Area under the valdecoxib concentration-time curve was similar to that in adults (40 mg), and simulated free valdecoxib concentration was above the cyclooxygenase-2 in vitro 50% inhibitory concentration for free valdecoxib for at least 12 h.

scholarly journals Pharmacokinetics of Daptomycin in Critically Ill Pediatric Patients

2018 ◽  
Vol 62 (6) ◽  
Author(s):  
Charalampos Antachopoulos ◽  
Stavroula Ilia ◽  
Paschalis Kadiltzoglou ◽  
Eirini Baira ◽  
Aristides Dokoumetzidis ◽  
...  
Keyword(s):  
Critically Ill ◽  
Drug Exposure ◽  
Pediatric Patients ◽  
Plasma Concentrations ◽  
Therapeutic Drug ◽  
Burn Patients ◽  
Time Curve ◽  
Once Daily ◽  
Concentration Time ◽  
Optimal Drug

ABSTRACT The pharmacokinetics of daptomycin (10 mg/kg once daily) was studied in 4 critically ill pediatric patients aged 8 to 14 yrs. The area under the concentration-time curve from time zero to infinity (AUC 0–∞ ) of plasma concentrations on day 1 ranged between 123.8 to 663.9 μg · h/ml, with lower values observed in septic and burn patients; clearance ranged from 15.1 to 80.7 ml/h/kg. Higher-than-recommended doses of daptomycin may be needed in septic children to ensure optimal drug exposure. Interpatient variability may suggest a role for therapeutic drug monitoring.

scholarly journals Exposure-Response Analyses of Tigecycline Efficacy in Patients with Complicated Skin and Skin-Structure Infections

2007 ◽  
Vol 51 (6) ◽  
pp. 1939-1945 ◽  
Author(s):  
A. K. Meagher ◽  
J. A. Passarell ◽  
B. B. Cirincione ◽  
S. A. Van Wart ◽  
K. Liolios ◽  
...  
Keyword(s):  
Sample Size ◽  
Regression Tree ◽  
Classification And Regression Tree ◽  
Loading Dose ◽  
Time Curve ◽  
Skin Structure ◽  
Exposure Response ◽  
Concentration Time ◽  
Complicated Skin ◽  
Clinical Responses

ABSTRACT Exposure-response analyses were performed for the microbiological and clinical efficacy of tigecycline in the treatment of complicated skin and skin-structure infections, where Staphylococcus aureus and streptococci are the predominant pathogens. A prospective method was developed to create homogeneous patient populations for PK-PD analyses. Evaluable patients from three clinical trials were pooled for analysis. Patients received a tigecycline 100-mg loading dose/50 mg every 12 h or a 50-mg loading dose/25 mg every 12 h. At the test-of-cure visit, microbiologic and clinical responses were evaluated. Patients were prospectively evaluated and classified into cohorts based on baseline pathogens: S. aureus only (cohort 1), monomicrobial S. aureus or streptococci (cohort 2), two gram-positive pathogens (cohort 3), polymicrobial (cohort 4), or other monomicrobial infections (cohort 5). A prospective procedure for combining cohorts was used to increase the sample size. Logistic regression evaluated steady-state 24-h area under the concentration-time curve (AUC24)/MIC ratio as a predictor of response, and classification and regression tree (CART) analyses were utilized to determine AUC/MIC breakpoints. Analysis began with pooled cohorts 2 and 3, the focus of these analyses, and included 35 patients with 40 S. aureus and/or streptococcal pathogens. CART analyses identified a significant AUC/MIC breakpoint of 17.9 (P = 0.0001 for microbiological response and P = 0.0376 for clinical response). The continuous AUC/MIC ratio was predictive of microbiological response based on sample size (P = 0.0563). Analysis of all pathogens combined decreased the ability to detect exposure-response relationships. The prospective approach of creating homogeneous populations based on S. aureus and streptococci pathogens was critical for identifying exposure-response relationships.

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