Publications by authors named "Mario R Sampson"

Purpose Of Review: Outline some regulatory considerations and scientific challenges related to the development of long-acting antiretrovirals (ARVs) for the treatment and prevention of HIV-1 infection.

Recent Findings: Poor adherence to oral ARV regimens continues to pose challenges for effective treatment and prevention of HIV-1 infection. The development of long-acting ARV modalities for treatment and prevention of HIV-1 infection is emerging as a promising alternative to the current treatment and prevention paradigm and has gained considerable interest.

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: Product labels for cobicistat with atazanavir or darunavir, and for elvitegravir/cobicistat/emtricitabine/tenofovir (alafenamide or disoproxil fumarate) were recently updated to state that these products are not recommended for initiation during pregnancy, and an alternative regimen is recommended for those who become pregnant during therapy with these products. Herein, we present the rationale for these recommendations, which are based on studies in pregnant women evaluating the pharmacokinetics and antiviral activity of darunavir/cobicistat or elvitegravir/cobicistat-containing antiretroviral regimens. In these studies, mean steady-state minimum concentrations in the second and third trimester versus postpartum of cobicistat, darunavir, and elvitegravir were reduced by 61-83%, 89-92%, and 82-86%, respectively.

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This review summarizes the significant impact of cytomegalovirus (CMV) infection on solid organ and hematopoietic stem cell transplant recipients. A discussion of the various CMV prevention and treatment strategies is provided, including a detailed description of each of the available CMV antiviral drugs.

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Although current quetiapine labeling recommends that its dosage should be lowered 6-fold when coadministered with strong cytochrome P450 (CYP)3A inhibitors, a reported case of coma in a patient receiving quetiapine with lopinavir and ritonavir prompted the reevaluation of labeling recommendations for the dosing of quetiapine when coadministered with human immunodeficiency virus (HIV) protease inhibitors. Literature and database (FDA Adverse Event Reporting System and United States Symphony Health Solutions' Integrated Dataverse Database) searches allowed us to identify cases of coma and related adverse events involving the coadministration of quetiapine and HIV protease inhibitors and to estimate the frequency of concomitant use. Literature review and physiologically based pharmacokinetic modeling allowed us to estimate the potential for CYP3A inhibition to contribute to adverse events related to HIV protease inhibitor-quetiapine coadministration.

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Unlabelled: Aims Sildenafil is frequently prescribed to children with single ventricle heart defects. These children have unique hepatic physiology with elevated hepatic pressures, which may alter drug pharmacokinetics. We sought to determine the impact of hepatic pressure on sildenafil pharmacokinetics in children with single ventricle heart defects.

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Background: Population pharmacokinetic (popPK) models derived from small pharmacokinetics (PK) studies in neonates are often underpowered to detect clinically important characteristics that drive dosing. External validation of such models is crucial. In this study, the predictive performance of a gentamicin popPK model in neonates receiving hypothermia was evaluated.

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Background: Acyclovir is used to treat herpes infections in preterm and term infants; however, the influence of maturation on drug disposition and dosing requirements is poorly characterized in this population.

Methods: We administered intravenous acyclovir to preterm and term infants <31 days postnatal age and collected plasma samples. We performed a population pharmacokinetic analysis.

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Despite metronidazole's widespread clinical use since the 1960s, the specific enzymes involved in its biotransformation have not been previously identified. Hence, in vitro studies were conducted to identify and characterize the cytochrome P450 enzymes involved in the formation of the major metabolite, 2-hydroxymetronidazole. Formation of 2-hydroxymetronidazole in human liver microsomes was consistent with biphasic, Michaelis-Menten kinetics.

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Clinical trials in children are challenging and filled with important ethical considerations that differ from adults. Given difficulties associated with pediatric clinical trials, off-label prescribing is a common practice in pediatrics, which can lead to adverse safety events and efficacy failures. To overcome these consequences, in the past 15 years, legislation in the USA and Europe has provided incentives to industry and increased government funding to conduct pediatric trials.

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