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Nutrients Oct 2019The pharmacokinetics of vitamin C (vitC) is indeed complex. Regulated primarily by a family of saturable sodium dependent vitC transporters (SVCTs), the absorption and... (Review)
Review
The pharmacokinetics of vitamin C (vitC) is indeed complex. Regulated primarily by a family of saturable sodium dependent vitC transporters (SVCTs), the absorption and elimination are highly dose-dependent. Moreover, the tissue specific expression levels and subtypes of these SVCTs result in a compartmentalized distribution pattern with a diverse range of organ concentrations of vitC at homeostasis ranging from about 0.2 mM in the muscle and heart, and up to 10 mM in the brain and adrenal gland. The homeostasis of vitC is influenced by several factors, including genetic polymorphisms and environmental and lifestyle factors such as smoking and diet, as well as diseases. Going from physiological to pharmacological doses, vitC pharmacokinetics change from zero to first order, rendering the precise calculation of dosing regimens in, for example, cancer and sepsis treatment possible. Unfortunately, the complex pharmacokinetics of vitC has often been overlooked in the design of intervention studies, giving rise to misinterpretations and erroneous conclusions. The present review outlines the diverse aspects of vitC pharmacokinetics and examines how they affect vitC homeostasis under a variety of conditions.
Topics: Ascorbic Acid; Ascorbic Acid Deficiency; Diffusion; Female; Homeostasis; Humans; Intestinal Absorption; Nutritional Requirements; Pregnancy; Smoking; Sodium-Coupled Vitamin C Transporters; Tissue Distribution
PubMed: 31601028
DOI: 10.3390/nu11102412 -
Marine Drugs Nov 2020Marine organisms represent an excellent source of innovative compounds that have the potential for the development of new drugs. The pharmacokinetics of marine drugs has... (Review)
Review
Marine organisms represent an excellent source of innovative compounds that have the potential for the development of new drugs. The pharmacokinetics of marine drugs has attracted increasing interest in recent decades due to its effective and potential contribution to the selection of rational dosage recommendations and the optimal use of the therapeutic arsenal. In general, pharmacokinetics studies how drugs change after administration via the processes of absorption, distribution, metabolism, and excretion (ADME). This review provides a summary of the pharmacokinetics studies of marine-derived active compounds, with a particular focus on their ADME. The pharmacokinetics of compounds derived from algae, crustaceans, sea cucumber, fungus, sea urchins, sponges, mollusks, tunicate, and bryozoan is discussed, and the pharmacokinetics data in human experiments are analyzed. In-depth characterization using pharmacokinetics is useful for obtaining information for understanding the molecular basis of pharmacological activity, for correct doses and treatment schemes selection, and for more effective drug application. Thus, an increase in pharmacokinetic research on marine-derived compounds is expected in the near future.
Topics: Animals; Aquatic Organisms; Biological Availability; Biological Products; Drug Dosage Calculations; Half-Life; Humans; Metabolic Clearance Rate; Tissue Distribution
PubMed: 33182407
DOI: 10.3390/md18110557 -
Nutrients Sep 2019The yellow pigment curcumin, extracted from turmeric, is a renowned polyphenol with a broad spectrum of health properties such as antioxidant, anti-inflammatory,... (Review)
Review
The yellow pigment curcumin, extracted from turmeric, is a renowned polyphenol with a broad spectrum of health properties such as antioxidant, anti-inflammatory, anti-cancer, antidiabetic, hepatoprotective, anti-allergic, anti-dermatophyte, and neuroprotective. However, these properties are followed by a poor pharmacokinetic profile which compromises its therapeutic potential. The association of low absorption by the small intestine and the extensive reductive and conjugative metabolism in the liver dramatically weakens the oral bioavailability. Several strategies such as inhibition of curcumin metabolism with adjuvants as well as novel solid and liquid oral delivery systems have been tried to counteract curcumin poor absorption and rapid elimination from the body. Some of these drug deliveries can successfully enhance the solubility, extending the residence in plasma, improving the pharmacokinetic profile and the cellular uptake.
Topics: Biological Availability; Curcuma; Curcumin; Drug Delivery Systems; Humans; Intestinal Absorption; Intestine, Small; Liver; Solubility
PubMed: 31500361
DOI: 10.3390/nu11092147 -
Nucleic Acids Research Jul 2021Because undesirable pharmacokinetics and toxicity of candidate compounds are the main reasons for the failure of drug development, it has been widely recognized that...
Because undesirable pharmacokinetics and toxicity of candidate compounds are the main reasons for the failure of drug development, it has been widely recognized that absorption, distribution, metabolism, excretion and toxicity (ADMET) should be evaluated as early as possible. In silico ADMET evaluation models have been developed as an additional tool to assist medicinal chemists in the design and optimization of leads. Here, we announced the release of ADMETlab 2.0, a completely redesigned version of the widely used AMDETlab web server for the predictions of pharmacokinetics and toxicity properties of chemicals, of which the supported ADMET-related endpoints are approximately twice the number of the endpoints in the previous version, including 17 physicochemical properties, 13 medicinal chemistry properties, 23 ADME properties, 27 toxicity endpoints and 8 toxicophore rules (751 substructures). A multi-task graph attention framework was employed to develop the robust and accurate models in ADMETlab 2.0. The batch computation module was provided in response to numerous requests from users, and the representation of the results was further optimized. The ADMETlab 2.0 server is freely available, without registration, at https://admetmesh.scbdd.com/.
Topics: Drug-Related Side Effects and Adverse Reactions; Internet; Pharmaceutical Preparations; Pharmacokinetics; Phthalazines; Piperazines; Software
PubMed: 33893803
DOI: 10.1093/nar/gkab255 -
Nutrients Jul 2019Despite the presumption of the beneficial effects of magnesium supplementation, little is known about the pharmacokinetics of different magnesium formulations. We aimed...
Despite the presumption of the beneficial effects of magnesium supplementation, little is known about the pharmacokinetics of different magnesium formulations. We aimed to investigate the value of two in vitro approaches to predict bioavailability of magnesium and to validate this in subsequent in vivo testing. In vitro assessment of 15 commercially available magnesium formulations was performed by means of a Simulator of the Human Intestinal Microbial Ecosystem (SHIME) and by dissolution tests. Two magnesium formulations with contrasting bioavailability prediction from both in vitro tests (best vs. worst) were selected for in vivo testing in 30 subjects. In vivo bioavailability was compared following one acute ingestion by monitoring blood magnesium concentrations up to 6 h following intake. The in vitro tests showed a very wide variation in absorption and dissolution of the 15 magnesium products. In the in vivo testing, a significant different serum magnesium absorption profile was found up to 4 h following supplement ingestion for the two supplements with opposing in vitro test results. Moreover, maximal serum magnesium increase and total area under the curve were significantly different for both supplements (+6.2% vs. +4.6% and 6.87 vs. 0.31 mM.min, respectively). Collectively, poor bioaccessibility and bioavailability in the SHIME model clearly translated into poor dissolution and poor bioavailability in vivo. This provides a valid methodology for the prediction of in vivo bioavailability and effectiveness of micronutrients by specific in vitro approaches.
Topics: Adolescent; Adult; Biological Availability; Dietary Supplements; Dosage Forms; Drug Liberation; Female; Humans; Magnesium; Male; Young Adult
PubMed: 31330811
DOI: 10.3390/nu11071663 -
Seminars in Perinatology Apr 2020
Topics: Biomedical Research; Congresses as Topic; Female; Humans; Information Dissemination; Pharmacoepidemiology; Pharmacogenetics; Pharmacokinetics; Pharmacological Phenomena; Pregnancy
PubMed: 32197796
DOI: 10.1016/j.semperi.2020.151220 -
Seminars in Perinatology Apr 2020Pharmacologic interventions play a major role in obstetrical care throughout pregnancy, labor and delivery and the postpartum. Traditionally, obstetrical providers have... (Review)
Review
Pharmacologic interventions play a major role in obstetrical care throughout pregnancy, labor and delivery and the postpartum. Traditionally, obstetrical providers have utilized standard dosing regimens developed for non-obstetrical indications based on pharmacokinetic knowledge from studies in men or non-pregnant women. With the recognition of pregnancy as a special pharmacokinetic population in the late 1990s, investigators have begun to study drug disposition in this unique patient dyad. Many of the basic physiologic changes that occur during pregnancy have significant impact on drug absorption, distribution and clearance. Activity of Phase I and Phase II drug metabolizing enzymes are differentially altered by pregnancy, resulting in drug concentrations sufficiently different for some medications that efficacy or toxicity is affected. Placental transporters play a major dynamic role in determining fetal drug exposure. In the past two decades, we have begun to expand our understanding of obstetrical pharmacology; however, to truly optimize pharmacologic care of our pregnant patients and their developing fetus, additional research is critically needed.
Topics: ATP-Binding Cassette Transporters; Absorption, Physiological; Cardiac Output; Cytochrome P-450 Enzyme System; Drug Elimination Routes; Female; Glomerular Filtration Rate; Humans; Maternal-Fetal Exchange; Multidrug Resistance-Associated Proteins; Organic Cation Transport Proteins; Pharmaceutical Preparations; Pharmacokinetics; Placenta; Plasma Volume; Pregnancy; Tissue Distribution
PubMed: 32115202
DOI: 10.1016/j.semperi.2020.151221 -
Journal of Clinical Pharmacology Feb 2020Target-mediated drug disposition (TMDD) is a term to describe a nonlinear pharmacokinetic (PK) phenomenon that is caused by high-affinity binding of a compound to its... (Review)
Review
Target-mediated drug disposition (TMDD) is a term to describe a nonlinear pharmacokinetic (PK) phenomenon that is caused by high-affinity binding of a compound to its pharmacologic targets. As the interaction between a drug and its pharmacologic target belongs to the process of pharmacodynamics (PD), TMDD can be viewed as a consequence of "PD affecting PK." Although there are numerous TMDD-related articles in the literature, most of them focus on characterizing TMDD using various mathematical models, which may not be suitable for those readers who have little interest in mathematical modeling and only want to have an understanding of the basic concept. The goal of this review is to serve as a "primer" on TMDD. This review explains (1) how TMDD happens; (2) why large-molecule and small-molecule compounds exhibiting TMDD demonstrate substantially different nonlinear PK behaviors; (3) what nonlinear PK profiles look like in large-molecule and small-molecule compounds exhibiting TMDD, using pegfilgrastim, erythropoietin, ABT-384, and linagliptin as case examples; and (4) how to identify whether the nonlinear PK of a compound is because of TMDD.
Topics: Animals; Drug Delivery Systems; Humans; Nonlinear Dynamics; Pharmaceutical Preparations; Pharmacokinetics; Tissue Distribution
PubMed: 31793004
DOI: 10.1002/jcph.1545 -
Antimicrobial Agents and Chemotherapy Sep 2021Augmented renal clearance (ARC) can cause underexposure to vancomycin, thereby increasing the risk of treatment failure. Our objective was to evaluate population...
Augmented renal clearance (ARC) can cause underexposure to vancomycin, thereby increasing the risk of treatment failure. Our objective was to evaluate population pharmacokinetics and optimize the dosing regimen of vancomycin in a pediatric population with ARC. Sparse pharmacokinetic sampling and therapeutic drug monitoring (TDM) data were collected from pediatric patients with ARC treated with vancomycin. A pharmacokinetic model was developed using NONMEM 7.2. The dosing regimen was optimized using Monte Carlo dose simulations. A total of 242 vancomycin serum concentrations from 113 patients (age range, 0.4 to 14.9 years; 49 females and 64 males) were available. The mean vancomycin dose was 58.8 mg/kg body weight/day (13.6 mg/kg/dose), and the mean vancomycin serum trough concentration was 6.5 mg/liter. A one-compartment pharmacokinetic model with first-order elimination was developed. Body weight and age were the most significant and positive covariates for clearance and volume of distribution. For the pediatric population with ARC, the current recommended vancomycin dose of 60 mg/kg/day was associated with a high risk of underdosing. To reach the target area under the concentration-time curve over 24 h in the steady state divided by the MIC (AUC/MIC) ratio of 400 to 700 in these pediatric patients, the vancomycin dose should be increased to 75 mg/kg/day for infants and children between 1 month and 12 years of age and 70 mg/kg/day for adolescents between 12 and 18 years of age. In conclusion, a one-compartment pharmacokinetic model with first-order elimination was established with body weight and age as significant covariates. An optimal dosing regimen was developed in pediatric patients with ARC aged 1 month to 18 years.
Topics: Adolescent; Aged; Anti-Bacterial Agents; Area Under Curve; Child; Child, Preschool; Female; Humans; Infant; Male; Metabolic Clearance Rate; Monte Carlo Method; Retrospective Studies; Vancomycin
PubMed: 34339268
DOI: 10.1128/AAC.00897-21 -
Biology of Sex Differences Jun 2020Women experience adverse drug reactions, ADRs, nearly twice as often as men, yet the role of sex as a biological factor in the generation of ADRs is poorly understood....
BACKGROUND
Women experience adverse drug reactions, ADRs, nearly twice as often as men, yet the role of sex as a biological factor in the generation of ADRs is poorly understood. Most drugs currently in use were approved based on clinical trials conducted on men, so women may be overmedicated. We determined whether sex differences in drug pharmacokinetics, PKs, predict sex differences in ADRs.
METHODS
Searches of the ISI Web of Science and PubMed databases were conducted with combinations of the terms: drugs, sex or gender, pharmacokinetics, pharmacodynamics, drug safety, drug dose, and adverse drug reaction, which yielded over 5000 articles with considerable overlap. We obtained information from each relevant article on significant sex differences in PK measures, predominantly area under the curve, peak/maximum concentrations, and clearance/elimination rates. ADRs were identified from every relevant article and recorded categorically as female-biased, male-biased, or not sex-biased.
RESULTS
For most of the FDA-approved drugs examined, elevated blood concentrations and longer elimination times were manifested by women, and these PKs were strongly linked to sex differences in ADRs. Of the 86 drugs evaluated, 76 had higher PK values in women; for 59 drugs with clinically identifiable ADRs, sex-biased PKs predicted the direction of sex-biased ADRs in 88% of cases. Ninety-six percent of drugs with female-biased PK values were associated with a higher incidence of ADRs in women than men, but only 29% of male-biased PKs predicted male-biased ADRs. Accessible PK information is available for only a small fraction of all drugs CONCLUSIONS: Sex differences in pharmacokinetics strongly predict sex-specific ADRs for women but not men. This sex difference was not explained by sex differences in body weight. The absence of sex-stratified PK information in public records for hundreds of drugs raises the concern that sex differences in PK values are widespread and of clinical significance. The common practice of prescribing equal drug doses to women and men neglects sex differences in pharmacokinetics and dimorphisms in body weight, risks overmedication of women, and contributes to female-biased adverse drug reactions. We recommend evidence-based dose reductions for women to counteract this sex bias.
Topics: Adverse Drug Reaction Reporting Systems; Drug-Related Side Effects and Adverse Reactions; Female; Humans; Male; Pharmacokinetics; Sex Characteristics
PubMed: 32503637
DOI: 10.1186/s13293-020-00308-5