Abstract:
:The importance of in-depth knowledge about the pharmacokinetics of a drug is evident because pharmacokinetic behaviour may correlate with activity and toxicity. The most elaborate pharmacokinetic investigation is a so-called mass balance study employing a radioactive tracer. A mass balance study investigates the plasma pharmacokinetics and excretion of both the unchanged drug and the total radioactivity (drug and metabolites), and allows elucidation of the metabolic fate of a drug. The main objective is the maximum recovery of the radioactive dose in urine and faeces. However, there is little concrete guidance on how to perform or assess such a mass balance study. Based on a critical review of the available literature and regulation, we discuss the design, conduct and evaluation of mass balance studies. The study must be preceded by pre-clinical studies to optimise the design. Compliance with available regulation (US FDA is more specific than European guidelines), choice of radioisotope (tritium may be lost and is consequently used less often), selection of subjects and safe administration of a relevant dose are critical. The drug (both the labelled and the non-labelled portion of the dose) must be prepared, characterised and administered, and the biological samples must be collected and analysed properly to obtain reliable and meaningful results. A recent development is the use of highly sensitive accelerator mass spectrometry for (14)C-detection, which allows the use of much lower amounts of radioactivity. Calculating the mass balance requires quantification of any possible losses of radioactivity during the study, e.g. during administration (adsorption to tubing). Total recovery should be at least 90% of the administered dose. A lower recovery, which is not uncommon, must be explained by biological factors such as a long decay half-life, irreversible binding to tissue components, or loss through expiration. The extent and relevance of metabolism is determined by comparing the pharmacokinetics of the unchanged drug and the total radioactivity. Metabolic profiling supplements existing knowledge of metabolism. We illustrate the important aspects of a mass balance study with literature on anticancer drugs. This review could serve as guidance for future mass balance studies.
journal_name
Clin Pharmacokinetjournal_title
Clinical pharmacokineticsauthors
Beumer JH,Beijnen JH,Schellens JHdoi
10.2165/00003088-200645010-00003keywords:
subject
Has Abstractpub_date
2006-01-01 00:00:00pages
33-58issue
1eissn
0312-5963issn
1179-1926pii
4513journal_volume
45pub_type
杂志文章,评审abstract::Cyclosporin (cyclosporin A) has been used as an immunosuppressive agent after organ transplantation for more than 15 years. The bioavailability of cyclosporin in its conventional oral formulation 'Sandimmun' displays considerable inter- and intra-patient variability. Absorption is also bile dependent. Recently, a new ...
journal_title:Clinical pharmacokinetics
pub_type: 杂志文章,评审
doi:10.2165/00003088-199630030-00001
更新日期:1996-03-01 00:00:00
abstract::Interleukins and tumour necrosis factor (TNF) are a complex group of proteins and glycoproteins able to exert pleiotropic effects with respect to a number of different target cells. In physiological conditions, they are induced and released in basal amounts only in restricted microenvironments where they have paracrin...
journal_title:Clinical pharmacokinetics
pub_type: 杂志文章,评审
doi:10.2165/00003088-199121040-00004
更新日期:1991-10-01 00:00:00
abstract::It has been suggested that the minimum effective serum clozapine concentration for an acceptable clinical response (threshold value) is about 400 micrograms/L. This article argues against the use of therapeutic drug monitoring (TDM) as a tool to obtain clozapine concentrations of > or = 400 micrograms/L in the individ...
journal_title:Clinical pharmacokinetics
pub_type: 杂志文章,评审
doi:10.2165/00003088-199834060-00005
更新日期:1998-06-01 00:00:00
abstract:OBJECTIVE:To evaluate the effect of cilostazol administration on warfarin pharmacokinetics and pharmacodynamics following a single 25 mg dose of warfarin. DESIGN:A randomised double-blind 2-period crossover with healthy volunteers receiving either 100 mg cilostazol twice daily for 13 days or matching placebo twice dai...
journal_title:Clinical pharmacokinetics
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.2165/00003088-199937002-00009
更新日期:1999-01-01 00:00:00
abstract::Adequate immunosuppression minimising the risk of organ rejection with acceptable tolerability of the used drugs is a crucial step in organ transplantation. The primary goal is to maintain a consistent time-dependent target concentration by tailoring individual dosage leading to the best efficacy and tolerability comb...
journal_title:Clinical pharmacokinetics
pub_type: 杂志文章,评审
doi:10.2165/00003088-200241050-00001
更新日期:2002-01-01 00:00:00
abstract:BACKGROUND AND OBJECTIVE:Daclizumab high-yield process (DAC HYP) is a humanized monoclonal antibody that selectively blocks the α-subunit (CD25) of the high-affinity interleukin-2 receptors, and has shown robust efficacy as a treatment for multiple sclerosis (MS). This work quantitatively characterized the relationship...
journal_title:Clinical pharmacokinetics
pub_type: 杂志文章,随机对照试验
doi:10.1007/s40262-015-0305-z
更新日期:2016-01-01 00:00:00
abstract::Various pharmacokinetic models, both simple and complex, have been developed to describe the way in which the rate of hepatic elimination of drugs depends on hepatic blood flow, hepatic intrinsic clearance and unbound fraction of drug in blood. A model is necessary because it is not possible to measure the average blo...
journal_title:Clinical pharmacokinetics
pub_type: 杂志文章,评审
doi:10.2165/00003088-199018010-00004
更新日期:1990-01-01 00:00:00
abstract::The critically ill patient occupies an increasing amount of time and bed space in modern hospital practice, and also commands increasing expenditure. Drug therapy in these patients has, in the past, been based on data derived from healthy volunteers, fit anaesthetised patients undergoing minor operative procedures, or...
journal_title:Clinical pharmacokinetics
pub_type: 杂志文章,评审
doi:10.2165/00003088-198814060-00003
更新日期:1988-06-01 00:00:00
abstract:BACKGROUND:Bitopertin (RG1678) is a glycine reuptake inhibitor currently in phase 3 trials for treatment of schizophrenia. This paper describes the use of physiologically based pharmacokinetic (PBPK) modelling and preclinical data to gain insights into and predict bitopertin clinical pharmacokinetics. METHODS:Simulati...
journal_title:Clinical pharmacokinetics
pub_type: 杂志文章,随机对照试验
doi:10.1007/s40262-013-0061-x
更新日期:2013-08-01 00:00:00
abstract::Ertugliflozin, a selective inhibitor of sodium-glucose cotransporter 2 (SGLT2), is approved in the US, EU, and other regions for the treatment of adults with type 2 diabetes mellitus (T2DM). This review summarizes the ertugliflozin pharmacokinetic (PK) and pharmacodynamic data obtained during phase I clinical developm...
journal_title:Clinical pharmacokinetics
pub_type: 杂志文章,评审
doi:10.1007/s40262-020-00875-1
更新日期:2020-08-01 00:00:00
abstract:OBJECTIVE:The aim of these studies was to determine the absolute bioavailability in healthy volunteers of inhaled fluticasone propionate (FP) administered as a single dose via the Diskhaler and Diskus powder devices, and the pharmacokinetics of inhaled FP after repeated administration via the Diskhaler device. METHODS...
journal_title:Clinical pharmacokinetics
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.2165/00003088-200039001-00004
更新日期:2000-01-01 00:00:00
abstract::Pregnancy is a specific dynamic state, and the potential usefulness of caring for a disorder in the fetus or the mother is now well established. Previously, pregnant women have been excluded from clinical trials, therefore only a few studies concerning evaluation of the pregestational metabolism or transplacental tran...
journal_title:Clinical pharmacokinetics
pub_type: 杂志文章,评审
doi:10.2165/00003088-199528020-00006
更新日期:1995-02-01 00:00:00
abstract::Haloperidol has been used extensively for the treatment of psychotic disorders, and it has been suggested that the monitoring of plasma haloperidol concentration is clinically useful. Different assay methodologies have been used in research and clinical practice to examine the relationship between response and plasma ...
journal_title:Clinical pharmacokinetics
pub_type: 杂志文章,评审
doi:10.2165/00003088-198917060-00004
更新日期:1989-12-01 00:00:00
abstract:BACKGROUND AND OBJECTIVE:To assess the influence of hepatitis C virus (HCV) co-infection and the extent of liver fibrosis on lopinavir/ritonavir pharmacokinetics in HIV-infected patients without liver function impairment. METHODS:Cross-sectional, comparative study enrolling HIV-infected adults receiving lopinavir/rito...
journal_title:Clinical pharmacokinetics
pub_type: 杂志文章
doi:10.2165/00003088-200746010-00005
更新日期:2007-01-01 00:00:00
abstract::Since 1989 there has been an exponential introduction of new antiepileptic drugs (AEDs) into clinical practice and these include eslicarbazepine acetate, felbamate, gabapentin, lacosamide, lamotrigine, levetiracetam, oxcarbazepine, perampanel, pregabalin, retigabine (ezogabine), rufinamide, stiripentol, tiagabine, top...
journal_title:Clinical pharmacokinetics
pub_type: 杂志文章,评审
doi:10.1007/s40262-013-0087-0
更新日期:2013-11-01 00:00:00
abstract::The effects of liver disease on pharmacokinetics and pharmacodynamics are highly variable, and difficult to predict as the mechanisms of these effects are not well understood. Since the majority of the published literature is concerned with cirrhotic liver disease, this review also focuses mainly on this area. Four di...
journal_title:Clinical pharmacokinetics
pub_type: 杂志文章,评审
doi:10.2165/00003088-199529050-00005
更新日期:1995-11-01 00:00:00
abstract::Sevoflurane is a comparatively recent addition to the range of inhalational anaesthetics which has been recently released for clinical use. In comparison to older inhalational agents such as isoflurane or halothane, the most important property of sevoflurane is its low solubility in the blood. This results in a more r...
journal_title:Clinical pharmacokinetics
pub_type: 杂志文章,评审
doi:10.2165/00003088-199936010-00002
更新日期:1999-01-01 00:00:00
abstract::Recent international guidelines on the detection, clinical assessment and management of patients with hypertension have highlighted a number of themes that should be incorporated into routine clinical practice. First, although antihypertensive therapy is having a major impact on reducing the incidence of coronary hear...
journal_title:Clinical pharmacokinetics
pub_type: 杂志文章,评审
doi:10.2165/00003088-199937001-00004
更新日期:1999-01-01 00:00:00
abstract::Calcineurin inhibitors, the primary immunosuppressive therapy used to prevent alloreactivity of transplanted organs, have a narrow therapeutic index. Currently, treatment is individualized based on clinical assessment of the risk of rejection or toxicity guided by trough concentration monitoring. Advances in immune mo...
journal_title:Clinical pharmacokinetics
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更新日期:2020-11-01 00:00:00
abstract::Protein binding of antibacterials in plasma and tissues has long been considered a component of their pharmacokinetic parameters, playing a potential role in distribution, excretion and therapeutic effectiveness. Since the beginning of the 'antibacterial era', this factor has been extensively analysed for all antibact...
journal_title:Clinical pharmacokinetics
pub_type: 杂志文章,评审
doi:10.2165/00003088-200241100-00004
更新日期:2002-01-01 00:00:00
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journal_title:Clinical pharmacokinetics
pub_type: 杂志文章
doi:10.2165/00003088-199324040-00007
更新日期:1993-04-01 00:00:00
abstract::Despite contributing significantly to the burden of global disease, the translation of new treatment strategies for diseases of the central nervous system (CNS) from animals to humans remains challenging, with a high attrition rate in the development of CNS drugs. The failure of clinical trials for CNS therapies can b...
journal_title:Clinical pharmacokinetics
pub_type: 杂志文章,评审
doi:10.1007/s40262-018-0632-y
更新日期:2018-09-01 00:00:00
abstract:BACKGROUND:Peripherally acting opioids, particularly peripheral κ-opioid agonists, may be effective for treating visceral pain by activating receptors expressed on afferent nerves within the gut. OBJECTIVE:The objective of this study was to investigate the pharmacokinetic/pharmacodynamic profile of a novel peripherall...
journal_title:Clinical pharmacokinetics
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1007/s40262-012-0023-8
更新日期:2013-02-01 00:00:00
abstract::Alemtuzumab is a humanized monoclonal antibody against CD52 and causes depletion of T and B lymphocytes, monocytes, and NK cells. Alemtuzumab is registered for the treatment of multiple sclerosis (MS) and is also used in chronic lymphocytic leukemia (CLL). Alemtuzumab is used off-label in kidney transplantation as ind...
journal_title:Clinical pharmacokinetics
pub_type: 杂志文章
doi:10.1007/s40262-017-0573-x
更新日期:2018-02-01 00:00:00
abstract::All of the commonly used anticonvulsants drugs, except possibly primidone, are cleared from the human body mainly by metabolism. The metabolites of phenytoin, phenobarbital and ethosuximide have so far not been shown to possess significant pharmacological activity. However, carbamazepine-10,11-epoxide, derived from ca...
journal_title:Clinical pharmacokinetics
pub_type: 杂志文章,评审
doi:10.2165/00003088-199121010-00003
更新日期:1991-07-01 00:00:00
abstract::The pharmacokinetics of CRP was tested in small short-term studies in both healthy volunteers and in subjects with schizophrenia, with similar results [242]. ...
journal_title:Clinical pharmacokinetics
pub_type: 已发布勘误
doi:10.1007/s40262-019-00797-7
更新日期:2019-09-01 00:00:00
abstract::In the original publication, Page 3, Sect. 4.3, the first sentence was incorrectly published. ...
journal_title:Clinical pharmacokinetics
pub_type: 杂志文章,已发布勘误
doi:10.1007/s40262-018-0633-x
更新日期:2018-05-01 00:00:00
abstract:OBJECTIVE:To study the pharmacokinetics of micafungin in intensive care patients and assess pharmacokinetic (PK) target attainment for various dosing strategies. METHODS:Micafungin PK data from 20 intensive care unit patients were available. A population-PK model was developed. Various dosing regimens were simulated: ...
journal_title:Clinical pharmacokinetics
pub_type: 杂志文章
doi:10.1007/s40262-017-0509-5
更新日期:2017-10-01 00:00:00
abstract:BACKGROUND AND AIMS:In this study, we evaluate the performance of allometric concepts to predict the implications of age and size on the pharmacokinetics of lamotrigine, and assess the dose rationale across different age groups from 0.2 to 91 years. METHODS:An allometrically scaled pharmacokinetic model was developed ...
journal_title:Clinical pharmacokinetics
pub_type: 杂志文章
doi:10.1007/s40262-017-0614-5
更新日期:2018-08-01 00:00:00
abstract:BACKGROUND AND OBJECTIVE:Oral levodopa-carbidopa (LC-oral) treatment in advanced Parkinson's disease (PD) is associated with motor complications due to large fluctuations in levodopa plasma concentrations. Levodopa-carbidopa intestinal gel (LCIG) provides individualized continuous levodopa-carbidopa delivery through in...
journal_title:Clinical pharmacokinetics
pub_type: 杂志文章,多中心研究,随机对照试验
doi:10.1007/s40262-015-0265-3
更新日期:2015-09-01 00:00:00