Prediction of Infant Drug Exposure Through Breastfeeding: Population PK Modeling and Simulation of Fluoxetine Exposure.

The likelihood of significant exposure to drugs in infants through breast milk is poorly defined, given the difficulties of conducting pharmacokinetics (PK) studies. Using fluoxetine (FX) as an example, we conducted a proof-of-principle study applying population PK (popPK) modeling and simulation to estimate drug exposure in infants through breast milk. We simulated data for 1,000 mother-infant pairs, assuming conservatively that the FX clearance in an infant is 20% of the allometrically adjusted value in adults. The model-generated estimate of the milk-to-plasma ratio for FX (mean: 0.59) was consistent with those reported in other studies. The median infant-to-mother ratio of FX steady-state plasma concentrations predicted by the simulation was 8.5%. Although the disposition of the active metabolite, norfluoxetine, could not be modeled, popPK-informed simulation may be valid for other drugs, particularly those without active metabolites, thereby providing a practical alternative to conventional PK studies for exposure risk assessment in this population.

Simultaneous quantification of selective serotonin reuptake inhibitors and metabolites in human plasma by liquid chromatography-electrospray mass spectrometry for therapeutic drug monitoring.

A simple and sensitive liquid chromatography-electrospray ionization mass spectrometry method was developed for the simultaneous quantification in human plasma of all selective serotonin reuptake inhibitors (citalopram, fluoxetine, fluvoxamine, paroxetine and sertraline) and their main active metabolites (desmethyl-citalopram and norfluoxetine). A stable isotope-labeled internal standard was used for each analyte to compensate for the global method variability, including extraction and ionization variations. After sample (250μl) pre-treatment with acetonitrile (500μl) to precipitate proteins, a fast solid-phase extraction procedure was performed using mixed mode Oasis MCX 96-well plate. Chromatographic separation was achieved in less than 9.0min on a XBridge C18 column (2.1×100mm; 3.5μm) using a gradient of ammonium acetate (pH 8.1; 50mM) and acetonitrile as mobile phase at a flow rate of 0.3ml/min. The method was fully validated according to Société Française des Sciences et Techniques Pharmaceutiques protocols and the latest Food and Drug Administration guidelines. Six point calibration curves were used to cover a large concentration range of 1-500ng/ml for citalopram, desmethyl-citalopram, paroxetine and sertraline, 1-1000ng/ml for fluoxetine and fluvoxamine, and 2-1000ng/ml for norfluoxetine. Good quantitative performances were achieved in terms of trueness (84.2-109.6%), repeatability (0.9-14.6%) and intermediate precision (1.8-18.0%) in the entire assay range including the lower limit of quantification. Internal standard-normalized matrix effects were lower than 13%. The accuracy profiles (total error) were mainly included in the acceptance limits of ±30% for biological samples. The method was successfully applied for routine therapeutic drug monitoring of more than 1600 patient plasma samples over 9 months. The β-expectation tolerance intervals determined during the validation phase were coherent with the results of quality control samples analyzed during routine use. This method is therefore precise and suitable both for therapeutic drug monitoring and pharmacokinetic studies in most clinical laboratories.

Agency Fact Sheet, Department of Governor Office of Drug Control Policy, FY2008

This document produced by the Iowa Department of Administrative Services has been developed to provide a multitude of information about executive branch agencies/department on a single sheet of paper. The facts provides general information, contact information, workforce data, leave and benefits information and affirmative action data.

Agency Fact Sheet, Office of Governor of Drug Control Policy, FY2009

This document produced by the Iowa Department of Administrative Services has been developed to provide a multitude of information about executive branch agencies/department on a single sheet of paper. The facts provides general information, contact information, workforce data, leave and benefits information and affirmative action data.

Suivi thérapeutique de l'imatinib = Therapeutische Drug-Monitoring von Imatinib

Monitoring spielt eine wichtige Rolle zur Therapieevaluierung und Behandlungsentscheidung - solange es auf der Basis der Messung von entsprechenden klinischen oder validierten Surrogat-Markern stattfindet. Im Hinblick auf die Imatinib-Therapie scheint das «Therapeutische Drug-Monitoring» (TDM) ein nützlicher Ansatz zum Therapie-Monitoring der CML-Behandlung zu sein, welches die Plasmakonzentration des Arzneimittels als Marker zur Therapieüberwachung verwendet. Imatinib-Plasmakonzentrationen variieren beträchtlich von Patient zu Patient unter dem gleichen Dosierungsschema, aufgrund der interindividuell unterschiedlichen Pharmakokinetik des Arzneimittels. Für die Plasmaexposition wurde gezeigt, dass sie mit dem klinischen Outcome von CML-Patienten korreliert - sowohl im Bezug auf das Therapieansprechen als auch auf das Nebenwirkungsprofil. Es ist noch unklar, ob das TDM von Imatinib nur im Falle von klinischen Problemen Verwendung finden sollte oder ob CML-Patienten bereits von einem systematischen, präventiven «Routine»-Monitoring zur Therapieindividualisierung - zur Steuerung der Plasmakonzentration in einen therapeutischen Bereich - profitieren könnten, welches in letzter Zeit immer häufiger empfohlen wird. Um diese Fragestellung zu beantworten, nimmt eine prospektive, randomisiert kontrollierte Schweizer Studie CML-Patienten auf, die seit weniger als 5 Jahren mit Imatinib behandelt werden, und bietet das TDM zudem für alle Patienten im Falle von klinischen Problemen an.

Agency Fact Sheet, Governor's Office of Drug Control Policy, FY2010

This document produced by the Iowa Department of Administrative Services has been developed to provide a multitude of information about executive branch agencies/department on a single sheet of paper. The facts provides general information, contact information, workforce data, leave and benefits information and affirmative action data.

Agency Fact Sheet, Governors Office of Drug Control Policy, FY2011

This document produced by the Iowa Department of Administrative Services has been developed to provide a multitude of information about executive branch agencies/department on a single sheet of paper. The facts provides general information, contact information, workforce data, leave and benefits information and affirmative action data.

Drug metabolism for the perplexed medicinal chemist.

Two related and significant issues may elicit perplexity in medicinal chemists and are discussed here. First, a broad presentation of the pharmacological and toxicological consequences of drug metabolism should justify the significance of drug metabolism and serve as an incentive to further study. When comparing the pharmacological activities of a drug and its metabolite(s), a continuum is found which ranges from soft drugs (no active metabolites) to prodrugs (inactive per se, as illustrated here with clopidogrel and prasugrel). Innumerable intermediate cases document drugs whose activity is shared by one or more metabolites, as exemplified with tamoxifen. The toxicological consequences of metabolism at the molecular, macromolecular, and macroscopic levels are manyfold. A brief overview is offered together with a summary of the reactions of toxification and detoxification of the antiepileptic valproic acid. The second issue discussed in the review is a comparison of the relative significance of cytochromes P450 and other oxidoreductases (EC 1), hydrolases (EC 3), and transferases (EC 2) in drug metabolism, based on a 'guesstimate' of the number of drug metabolites that are known to be produced by them. The conclusion is that oxidoreductases are the main enzymes responsible for the formation of toxic or active metabolites, whereas transferases play the major role in producing inactive and nontoxic metabolites.

Sunitinib-eluting beads for chemoembolization: methods for in vitro evaluation of drug release.

Drug-eluting microspheres are used for embolization of hypervascular tumors and allow for local controlled drug release. Although the drug release from the microspheres relies on fast ion-exchange, so far only slow-releasing in vitro dissolution methods have been correlated to in vivo data. Three in vitro release methods are assessed in this study for their potential to predict slow in vivo release of sunitinib from chemoembolization spheres to the plasma, and fast local in vivo release obtained in an earlier study in rabbits. Release in an orbital shaker was slow (t50%=4.5h, 84% release) compared to fast release in USP 4 flow-through implant cells (t50%=1h, 100% release). Sunitinib release in saline from microspheres enclosed in dialysis inserts was prolonged and incomplete (t50%=9 days, 68% release) due to low drug diffusion through the dialysis membrane. The slow-release profile fitted best to low sunitinib plasma AUC following injection of sunitinib-eluting spheres. Although limited by lack of standardization, release in the orbital shaker fitted best to local in vivo sunitinib concentrations. Drug release in USP flow-through implant cells was too fast to correlate with local concentrations, although this method is preferred to discriminate between different sphere types.

Agency Fact Sheet, Office of Drug Control Policy, FY2006

This document produced by the Iowa Department of Administrative Services has been developed to provide a multitude of information about executive branch agencies/department on a single sheet of paper. The facts provides general information, contact information, workforce data, leave and benefits information and affirmative action data.