Clin Pharmacokinet
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Randomized Controlled Trial
Effects of enteral feeding on the oral bioavailability of moxifloxacin in healthy volunteers.
Moxifloxacin is a new generation fluoroquinolone antimicrobial agent used worldwide. In clinical practice in intensive care units, moxifloxacin may be frequently administered through a nasogastric feeding tube. In the absence of an oral liquid formulation and since the multivalent cations contained in enteral feeds may potentially impair absorption of moxifloxacin administered via this route, we studied the effect of concomitant enteral feeding on the pharmacokinetics and tolerability of moxifloxacin administered as a crushed tablet through the nasogastric tube. ⋯ There was no clinically relevant effect of enteral feeding on the pharmacokinetics of oral moxifloxacin in healthy volunteers. This result has to be evaluated in patients, particularly those from the intensive care unit, who are characterised by severe infectious and/or concomitant diseases that might influence absorption of moxifloxacin.
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Comparative Study
The effect of aging on the relationship between the cytochrome P450 2C19 genotype and omeprazole pharmacokinetics.
The metabolic activity of cytochrome P450 (CYP) 2C19 is genetically determined, and the pharmacokinetics of omeprazole, a substrate for CYP2C19, are dependent on the CYP2C19 genotype. However, a discrepancy between the CYP2C19 genotype and omeprazole pharmacokinetics was reported in patients with liver disease or advanced cancer. The objective of the present study was to evaluate the effect of aging on the relationship between the CYP2C19 genotype and its phenotype. ⋯ The elderly EMs showed wide variance in the in vivo CYP2C19 activity and were phenotypically closer to the elderly PMs than the young EMs were to the young PMs. Some of the elderly homozygous EMs, as well as heterozygous EMs, have a metabolic activity similar to PMs, and the CYP2C19 genotype may therefore not be as useful as phenotyping in the elderly.
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Randomized Controlled Trial Comparative Study Clinical Trial
Characterisation of the pharmacokinetics of the fentanyl HCl patient-controlled transdermal system (PCTS): effect of current magnitude and multiple-day dosing and comparison with IV fentanyl administration.
The fentanyl HCl patient-controlled transdermal system (PCTS) is a self-contained, preprogrammed, noninvasive analgesic delivery system for acute pain management. We carried out three studies with the following objectives: study I to evaluate the relationship between fentanyl absorption and the magnitude of current applied to the system; study II to determine dose-proportionality for the fentanyl HCl PCTS (25 and 40 microg); and study III to describe the effects of single- and multiple-day administration on the pharmacokinetics of fentanyl delivered by the PCTS. ⋯ A linear relationship exists between the amount of current applied to the fentanyl HCl PCTS and the amount of fentanyl absorbed. There is dose-proportionality in the pharmacokinetics of the fentanyl HCl PCTS 25 and 40 microg. Multiple-day administration does not affect the pharmacokinetics of the fentanyl HCl PCTS 40 microg. The system was well tolerated, even after repeated application.
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Randomized Controlled Trial Multicenter Study Clinical Trial
Effects of application site and subject demographics on the pharmacokinetics of fentanyl HCl patient-controlled transdermal system (PCTS).
The fentanyl HCl patient-controlled transdermal system (PCTS) is a self-contained, preprogrammed, needle-free system currently in development for acute pain management in a medically supervised setting. The objectives of these studies were to evaluate skin application sites for the fentanyl HCl PCTS and to evaluate the effect of patient demographics on its pharmacokinetics. ⋯ Fentanyl HCl is comparably absorbed from the PCTS when it is applied to the upper outer arm or chest. The pharmacokinetics of fentanyl HCl delivered by the PCTS are unaffected by sex, age, race or weight.
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Randomized Controlled Trial Clinical Trial
Population pharmacokinetics of delavirdine and N-delavirdine in HIV-infected individuals.
Delavirdine is a non-nucleoside reverse transcriptase inhibitor used in combination regimens for the treatment of HIV-1 infection. Our objective was to characterise the population pharmacokinetics of delavirdine in HIV-infected patients who participated in the adult AIDS Clinical Trials Group (ACTG) 260 and 261 studies. ⋯ Delavirdine disposition exhibits nonlinear pharmacokinetics and large interpatient variability, and is significantly altered by time of day (impacting potential therapeutic drug monitoring and future pharmacokinetic study designs). Although race and sex appear to influence delavirdine pharmacokinetics, men and women and patients of different races should receive similar mg/kg dosage regimens. The presence of large interpatient variability supports the further investigation of the utility of therapeutic drug monitoring for delavirdine, if target drug concentrations can be better defined.