Clin Pharmacokinet
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Comparative Study Clinical Trial
Pharmacokinetics of mycophenolic acid and determination of area under the curve by abbreviated sampling strategy in Chinese liver transplant recipients.
This study aimed to: (i) define the clinical pharmacokinetics of mycophenolic acid (MPA) in Chinese liver transplant recipients; and (ii) develop a regression model best fitted for the prediction of MPA area under the plasma concentration-time curve from 0 to 12 hours (AUC(12)) by abbreviated sampling strategy. ⋯ This study showed the wide variability in MPA AUC(12) in Chinese liver transplant recipients. Single timepoint MPA concentration during the 12-hour dosing interval cannot reflect MPA AUC(12). MPA AUC(12) could be predicted accurately using 1, 2, 6 and 8 hour timepoint MPA concentrations by abbreviated sampling strategy.
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The FG loop peptide (FGL(L)), a novel mimetic of the neural cell adhesion molecule (NCAM), is in clinical development for neurodegenerative disorders such as Alzheimer's disease. Preclinical studies in rats, dogs and monkeys have demonstrated exposure in plasma and cerebrospinal fluid after parenteral or intranasal administration of FGL(L), with no systemic toxicity. This article reports on the results of the first administration of FGL(L) in humans. ⋯ Intranasal administration of FGL(L) (25, 100 and 200mg) was well tolerated in healthy male volunteers, with no safety concerns and a pharmacokinetic profile that was generally dose related. Further studies are currently being planned to evaluate the effects of FGL(L) in patients with Alzheimer's disease.
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A 26-year-old female was treated with morphine within the first 2 hours after knee surgery, in an attempt to titrate analgesia. The patient received a total of four intravenous injections of morphine 35 mg in total. Soon after the last injection the patient had adequate pain relief, was in a good clinical state and had adequate blood oxygenation. ⋯ Because of its slow transfer between plasma and the effect site, the CNS effects of morphine are delayed from its plasma concentrations to a clinically relevant degree. Successive injections at short intervals of relatively high amounts of morphine increase the clinical relevance of this delay. The present report demonstrates an important application of clinical pharmacokinetics for explaining clinical observations at a scientific level and transferring theoretical knowledge from clinical pharmacokinetics into daily clinical practice as a basis for rational opioid selection.
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Lamellar liposome technology has been used for several decades to produce sustained-release drug formulations for parenteral administration. Multivesicular liposomes are structurally distinct from lamellar liposomes and consist of an aggregation of hundreds of water-filled polyhedral compartments separated by bi-layered lipid septa. The unique architecture of multivesicular liposomes allows encapsulating drug with greater efficiency, provides robust structural stability and ensures reliable, steady and prolonged drug release. ⋯ Contingent on the specific formulation and manufacturing process, agents were released over a period of hours to weeks as reflected by a 2- to 400-fold increase in elimination half life. Published data further suggest that the encapsulation process preserves bioactivity of agents as delicate as proteins and supports the view that examined multivesicular liposomes were non-toxic at studied doses. The task ahead will be to examine whether the beneficial structural and pharmacokinetic properties of multivesicular liposome formulations will translate into improved clinical outcomes, either because of decreased drug toxicity or increased drug efficacy.
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Ethnic or racial differences in pharmacokinetics and pharmacodynamics have been attributed to the distinctions in the genetic, physiological and pathological factors between ethnic/racial groups. These pharmacokinetic/pharmacodynamic differences are also known to be influenced by several extrinsic factors such as socioeconomic background, culture, diet and environment. However, it is noted that other factors related to dosage regimen and dosage form have largely been ignored or overlooked when conducting or analysing pharmacokinetic/pharmacodynamic studies in relation to ethnicity/race. ⋯ The presence of genetic polymorphism of enzymes and/or transporters can further complicate the analysis of pharmacokinetic/pharmacodynamic data in ethnic/racial populations. Even within the same dosage regimen, the use of different dosage forms may trigger significantly different pharmacokinetic/pharmacodynamic responses in various ethnic/racial groups, given that different dosage forms may exhibit different rates of drug release, may release the drug at different sites, and/or have different retention times at specific sites of the body. It is thus cautioned that the pharmacokinetic/pharmacodynamic data obtained from different ethnic/racial groups cannot be indiscriminately compared or combined for analysis if there is a lack of homogeneity in the apparent 'extrinsic' factors, including dosage regimen and dosage form.