Search results for "Pharmacokinetic"
showing 10 items of 474 documents
A comparative study of the population pharmacokinetics of gentamicin and amikacin in newborn patients
1993
SUMMARY The population kinetics of gentamicin and amikacin were studied comparatively in newborn patients with a similar range of gestation age (37.9 ± 2.9 and 36.7 ± 3.6 weeks), postnatal age (13.8 ± 7.4 and 16.7 ± 7 days) and weight (2.85 ± 0.57 and 2.72 ± 0.75 kg), undergoing routine therapeutic monitoring of their serum levels. Individual kinetic analysis of serum drug levels was done using a single-compartment model. The population model employed assumes the existence of residual variability in the serum concentrations and interindividual variability in the pharmacokinetic parameters. The clearance and the apparent distribution volume were calculated for each patient using a two-stage …
Opioid metabolism and clinical aspects.
2015
Opioids are are commonly used for the management of acute and chronic pain. Opioids have different physicochemical and pharmacokinetic characteristics, which explain the profound changes in the clinical effect in several clinical conditions. Pharmacokinetics influences the opioid response affecting bioavailability, production of metabolites with residual clinical activity, and elimination. Generality of opioid metabolism and clinical implications for specific opioids in different clinical conditions were reviewed to bridge the gap between pharmacokinetics and clinical response. The knowledge of opioid metabolism is essential, particularly for older and complicated patients who receive multi…
Efecto de la administración concomitante de indometacina o ibuprofeno en la farmacocinética de amikacina en neonatos prematuros
2006
Objective: To evaluate whether the concomitant administration of ibuprofen or indomethacin plus amikacin may alter the latter drug's pharmacokinetic parameters, and hence amikacin plasma levels. Method: Retrospective cohort study performed by reviewing the medical records of premature children with persistent ductus arteriosus receiving amikacin and ibuprofen, or amikacin and indomethacin. They were divided up into three groups: group 1: treatment with amikacin went before indomethacin or ibuprofen; group 2: simultaneously treated with amikacin and indomethacin; group 3: simultaneously treated with amikacin and ibuprofen. Pharmacokinetic parameters, distribution volume, and amikacin clearan…
Increased bioavailability of oral melatonin after fluvoxamine coadministration*1
2000
Background Fluvoxamine, a selective serotonin reuptake inhibitor, is known to elevate melatonin serum concentrations. It has not been clear whether these effects might be attributed to an increased melatonin production or to an decreased elimination of melatonin. The latter hypothesis was tested by this study. Methods Five healthy male volunteers (one CYP2D6 poor metabolizer) received 5 mg melatonin either with or without coadministration of 50 mg fluvoxamine. Serum concentrations of melatonin and fluvoxamine were assessed from 0 to 28 hours after melatonin intake. Results Coadministration of fluvoxamine, on average, led to an 17-fold higher (P <.05) area under concentration–time curve (AUC…
Rewarding Properties of Testosterone in Intact Male Mice
2000
The present study examined the rewarding properties of 4-androsten-17β-ol-3-one testosterone in intact male mice using the conditioned place preference (CPP) technique. In Experiment 1, the pharmacokinetics of 0.8 and 1.2 mg/kg of testosterone were studied to determine the most appropriate temporal interval to test behavior. Additionally, the locomotor activity was recorded to control a possible interfering effect on CPP. The maximum testosterone concentration was registered at 45 min of administration, and no effects on activity were found. In Experiment 2, three groups of male OF-1 mice received four pairings of the least-preferred compartment with testosterone (0.8, 1, or 1.2 mg/kg, SC) …
Farmacocinética del metronidazol y la gentamicina en dosis única preoperatoria para profilaxis antibiótica quirúrgica en cirugía colorrectal
2008
Objective: To describe, in patients undergoing colorectal surgery (CRS), the pharmacokinetics of a single, prophylactic preoperative dose of 1,500 mg of metronidazole plus 240 mg gentamicin and measure its efficacy in accordance with the accepted pharmacodynamic and microbiological parameters. Method: Thirty-six patients undergoing CRS agreed to participate in the study. Three blood samples were taken from each. Cmax 15 minutes after finishing the infusion of the mixture, CfinIQ on finishing the surgery, and Cmin between 12 and 24 hours post-administration. The concentrations of metronidazole and gentamicin in each simple were measured and the pharmacokinetic parameters were estimated (dV- …
Monitorización de la vacomicina en administración intraperitoneal en pacientes sometidos a diálisis peritoneal continua ambulatoria
2012
Objective: To validate a pharmacokinetic model of the treatments with intraperitoneal vancomycin applied to patients on continuous ambulatory peritoneal dialysis with bacterial peritonitis. Methods: To carry out a prospective study divided in 2 cohorts: the first one including ten patients of 56 ± 14 years and 65 ± 5 kg, and the second one with 10 patients (12 episodes of peritonitis) aged 52 ± 13 years and 64 ± 8 kg. The treatment consists of administering and retaining for 6 h in the peritoneal cavity a solution containing 2 g of vancomycin and 1 g of ceftazidime into 2 l of ‘‘dialysis solution’’. After the antibiotic administration, blood samples were obtained at 4, 6, 8, 10, 24, 48 and …
Development of a nomogram for the estimation of long-term adherence to clozapine therapy using neutrophil fluorescence
2018
Aims: Previously, we have reported an association between clozapine use and elevated FL3 neutrophil fluorescence, a flow-cytometric parameter for cell viability. Here, we developed and evaluated a pharmacokinetic-pharmacodynamic model relating FL3-fluorescence to clozapine exposure and derived a nomogram for estimation of long-term adherence. Methods: Data from 27 patients initiating clozapine were analysed using nonlinear mixed effects modelling. A previously described pharmacokinetic model for clozapine was coupled to a FL3 fluorescence model. For this, an effect compartment with clozapine concentrations as input and a first order decay rate as output was linked with an Emax model to FL3-…
Formulation predictive dissolution (fPD) testing to advance oral drug product development: an introduction to the US FDA funded ‘21st Century BA/BE’ …
2018
Over the past decade, formulation predictive dissolution (fPD) testing has gained increasing attention. Another mindset is pushed forward where scientists in our field are more confident to explore the in vivo behavior of an oral drug product by performing predictive in vitro dissolution studies. Similarly, there is an increasing interest in the application of modern computational fluid dynamics (CFD) frameworks and high-performance computing platforms to study the local processes underlying absorption within the gastrointestinal (GI) tract. In that way, CFD and computing platforms both can inform future PBPK-based in silico frameworks and determine the GI-motility-driven hydrodynamic impac…
In vivo methods for drug absorption - comparative physiologies, model selection, correlations with in vitro methods (IVIVC), and applications for for…
2013
This review summarizes the current knowledge on anatomy and physiology of the human gastrointestinal tract in comparison with that of common laboratory animals (dog, pig, rat and mouse) with emphasis on in vivo methods for testing and prediction of oral dosage form performance. A wide range of factors and methods are considered in addition, such as imaging methods, perfusion models, models for predicting segmental/regional absorption, in vitro in vivo correlations as well as models to investigate the effects of excipients and the role of food on drug absorption. One goal of the authors was to clearly identify the gaps in today's knowledge in order to stimulate further work on refining the e…