Impact of CYP3A5 Polymorphisms on Pediatric Asthma Outcomes.

Genetic variation among inhaled corticosteroid (ICS)-metabolizing enzymes may affect asthma control, but evidence is limited. This study tested the hypothesis that single-nucleotide polymorphisms (SNPs) in Cytochrome P450 3A5 (CYP3A5) would affect asthma outcomes. Patients aged 2-18 years with persistent asthma were recruited to use the electronic AsthmaTracker (e-AT), a self-monitoring tool that records weekly asthma control, medication use, and asthma outcomes. A subset of patients provided saliva samples for SNP analysis and participated in a pharmacokinetic study. Multivariable regression analysis adjusted for age, sex, race, and ethnicity was used to evaluate the impact of CYP3A5 SNPs on asthma outcomes, including asthma control (measured using the asthma symptom tracker, a modified version of the asthma control test or ACT), exacerbations, and hospital admissions. Plasma corticosteroid and cortisol concentrations post-ICS dosing were also assayed using liquid chromatography-tandem mass spectrometry. Of the 751 patients using the e-AT, 166 (22.1%) provided saliva samples and 16 completed the PK study. The e-AT cohort was 65.1% male, and 89.6% White, 6.0% Native Hawaiian, 1.2% Black, 1.2% Native American, 1.8% of unknown race, and 15.7% Hispanic/Latino; the median age was 8.35 (IQR: 5.51-11.3) years. CYP3A5*3/*3 frequency was 75.8% in White subjects, 50% in Native Hawaiians and 76.9% in Hispanic/Latino subjects. Compared with CYP3A5*3/*3, the CYP3A5*1/*x genotype was associated with reduced weekly asthma control (OR: 0.98; 95% CI: 0.97-0.98; p < 0.001), increased exacerbations (OR: 6.43; 95% CI: 4.56-9.07; p < 0.001), and increased asthma hospitalizations (OR: 1.66; 95% CI: 1.43-1.93; p < 0.001); analysis of 3/*3, *1/*1 and *1/*3 separately showed an allelic copy effect. Finally, PK analysis post-ICS dosing suggested muted changes in cortisol concentrations for patients with the CYP3A5*3/*3 genotype, as opposed to an effect on ICS PK. Detection of CYP3A5*3/3, CYPA35*1/*3, and CYP3A5*1/*1 could impact inhaled steroid treatment strategies for asthma in the future.

The Cytochrome P450 (CYP) 2C8*3 Variant (rs11572080) is Associated with Improved Asthma Symptom Control in Children and Altered Lipid Mediator Production and Inflammatory Response in Human Bronchial Epithelial Cells.

This study investigated an association between the cytochrome P450 (CYP) 2C8*3 polymorphism with asthma symptom control in children and changes in lipid metabolism and pro-inflammatory signaling by human bronchial epithelial cells (HBECs) treated with cigarette smoke condensate (CSC). CYP genes are inherently variable in sequence and while such variations are known to produce clinically relevant effects on drug pharmacokinetics and pharmacodynamics, the effects on endogenous substrate metabolism and associated physiological processes are less understood. In this study, CYP2C8*3 was associated with improved asthma symptom control among children: Mean asthma control scores were 3.68 [n=207] for patients with one or more copies of the CYP2C8*3 allele vs. 4.42 [n=965] for CYP2C8*1/*1 (p=0.0133). In vitro, CYP2C8*3 was associated with an increase in montelukast 36-hydroxylation and a decrease in linoleic acid (LA) metabolism despite lower mRNA and protein expression. Additionally, CYP2C8*3 was associated with reduced mRNA expression of interleukin-6 (IL-6) and C-X-C motif chemokine ligand 8 (CXCL-8) by HBECs in response to CSC, which was replicated using the soluble epoxide hydrolase inhibitor, AUDA. Interestingly, 9(10)- and 12(13)-DiHOME, the hydrolyzed metabolites of 9(10)- and 12(13)-EpOME, increased the expression of IL-6 and CXCL-8 mRNA by HBECs. This study reveals previously undocumented effects of the CYP2C8*3 variant on the response of HBECs to exogenous stimuli. Significance Statement These findings suggest a role for CYP2C8 in regulating the EpOME:DiHOME ratio leading to a change in cellular inflammatory responses elicited by environmental stimuli that exacerbate asthma.

A ropivacaine-eluting poly(lactide-co-caprolactone) wound dressing provided enhanced analgesia in partial-thickness porcine injuries.

BACKGROUND: Partial-thickness skin wounds are some of the most painful injuries due to large areas of exposed nerve endings. These injuries often require systemic opioid treatments to manage pain adequately. However, in 2021 alone, the CDC reported nearly 17,000 prescription opioid-related deaths in the USA, highlighting the ongoing need for non-opioid treatment strategies. In this manuscript, we developed a novel single-application ropivacaine-eluting primary wound dressing that could provide sustained ropivacaine delivery to partial-thickness wounds and assessed its in vivo feasibility for prolonged non-opioid analgesia. METHODS: Sustained release of ropivacaine from a poly(lactide-co-e-caprolactone) matrix was first optimized in vitro using dissolution testing and a Box Behnken design of experiments. The optimized dressing was then tested against a clinical control silicone dressing in a porcine partial-thickness wound study to assess analgesic effect, pharmacokinetics, and wound healing. RESULTS: The ropivacaine-eluting dressing showed a moderate analgesic effect in vivo, where normalized single pinprick scores significantly improved pain over the testing period (4-168h) (control vs treatment: 232±25% vs 145±16%, p<0.0003). Ropivacaine blood plasma levels peaked at 8 hours post-treatment, with a maximum concentration of 246 ± 74 ng/mL. No significant differences in wound healing were found when compared to control. CONCLUSION: The ropivacaine-loaded poly(lactide-co-e-caprolactone)-based wound dressing provided sustained delivery of ropivacaine to partial-thickness skin wounds and enhanced analgesic effect compared to a clinical standard control dressing.

Clinical pharmacokinetics of atropine oral gel formulation in healthy volunteers.

Sialorrhea or drooling is a common problem in children and adults with neurodevelopmental disorders. It can negatively impact the quality of life due to its physical and psychological manifestations. Providers commonly prescribe atropine eye drops for topical administration to the oral mucosa, as an off-label treatment to manage sialorrhea. However, the off-label use of atropine eye drops can be associated with medication and dosing errors and systemic side effects. To address these limitations of treatment, we developed a mucoadhesive topical oral gel formulation of atropine as an alternative route to off-label administration of atropine eye drops. In this clinical pharmacokinetic (PK) study, we evaluated the safety and PK of atropine gel (0.01% w/w) formulation after single-dose administration to the oral mucosa in 10 healthy volunteers. The PK data showed that after topical administration to the oral mucosa, atropine followed a two-compartment PK profile. The maximum plasma concentration and area under the curve extrapolated to infinite time were 0.14 ng/mL and 0.74 h·ng·mL-1 , respectively. The absorption rate constant calculated by the compartmental analysis was 0.4 h-1 . Safety parameters, such as heart rate, blood pressure, and oxygen saturation, did not significantly change before and after administration of the gel formulation, and no adverse events were observed in all participants who received atropine gel. These data indicate that atropine gel formulation has a satisfactory PK profile, is well-tolerated at the dose studied, and can be further considered for clinical development as a drug product to treat sialorrhea.

HIV Prevention and Care Among Black Cisgender Sexual Minority Men and Transgender Women: Protocol for an HIV Status-Neutral Cohort Study Using an Observational-Implementation Hybrid Approach.

BACKGROUND: Black cisgender gay, bisexual, and other sexual minority men (SMM) and transgender women (TW) continue to be heavily affected by HIV. Further research is needed to better understand HIV prevention and care outcomes in this population. In particular, there is a need for research examining the impact of substance use and sleep health on HIV prevention and treatment outcomes among Black SMM and TW. OBJECTIVE: This paper outlines the study methods being used in the recently launched follow-up study to the Neighborhoods and Networks (N2) study, which we refer to as N2 Part 2 (N2P2). N2P2 aims to address this gap in the literature, build off the findings of the original N2 study, and identify socioenvironmental determinants of health, including whether neighborhood and network factors mediate and moderate these relationships. METHODS: Building on the N2 cohort study in Chicago from 2018 to 2022, N2P2 used a prospective longitudinal cohort design and an observational-implementation hybrid approach. With sustained high levels of community engagement, we aim to recruit a new sample of 600 Black SMM and TW participants residing in the Chicago metropolitan statistical area. Participants are asked to participate in 3 study visits across an 18-month study period (1 visit every 9 months). Four different forms of data are collected per wave: (1) an in-person survey, (2) biological specimen collection, (3) a daily remote ecological momentary assessment for 14 days after each study visit, and (4) data from electronic health records. These forms of data collection continue to assess neighborhood and network factors and specifically explore substance use, sleep, immune function, obesity, and the implementation of potential interventions that address relevant constructs (eg, alcohol use and pre-exposure prophylaxis adherence). RESULTS: The N2P2 study was funded in August 2021 by the National Institute of Drug Abuse (R01DA054553 and R21DA053156) and National Heart, Lung, and Blood Institute (R01HL160325). This study was launched in November 2022. Recruitment and enrollment for the first wave of data collection are currently ongoing. CONCLUSIONS: The N2P2 study is applying innovative methods to comprehensively explore the impacts of substance use and sleep health on HIV-related outcomes among an HIV status-neutral cohort of Black SMM and TW in Chicago. This study is applying an observational-implementation hybrid design to help us achieve findings that support rapid translation, a critical priority among populations such as Black SMM and TW that experience long-standing inequities with regard to HIV and other health-related outcomes. N2P2 will directly build off the findings that have resulted from the original N2 study among Black SMM and TW in Chicago. These findings provide a better understanding of multilevel (eg, individual, network, and neighborhood) factors that contribute to HIV-related outcomes and viral suppression among Black SMM and TW. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/48548.

Anakinra Removal by Continuous Renal Replacement Therapy: An Ex Vivo Analysis.

OBJECTIVES: Patients with sepsis are at significant risk for multiple organ dysfunction, including the lungs and kidneys. To manage the morbidity associated with kidney impairment, continuous renal replacement therapy (CRRT) may be required. The extent of anakinra pharmacokinetics in CRRT remains unknown. The objectives of this study were to investigate the anakinra-circuit interaction and quantify the rate of removal from plasma. DESIGN: The anakinra-circuit interaction was evaluated using a closed-loop ex vivo CRRT circuit. CRRT was performed in three phases based on the method of solute removal: 1) hemofiltration, 2) hemodialysis, and 3) hemodiafiltration. Standard control samples of anakinra were included to assess drug degradation. SETTING: University research laboratory. PATIENTS: None. INTERVENTIONS: Anakinra was administered to the CRRT circuit and serial prefilter blood samples were collected along with time-matched control and hemofiltrate samples. Each circuit was run in triplicate to assess inter-run variability. Concentrations of anakinra in each reference fluid were measured by enzyme-linked immunosorbent assay. Transmembrane filter clearance was estimated by the product of the sieving coefficient/dialysate saturation constant and circuit flow rates. MEASUREMENTS AND MAIN RESULTS: Removal of anakinra from plasma occurred within minutes for each CRRT modality. Average drug remaining (%) in plasma following anakinra administration was lowest with hemodiafiltration (34.9%). The average sieving coefficient was 0.34, 0.37, and 0.41 for hemodiafiltration, hemofiltration, and hemodialysis, respectively. Transmembrane clearance was fairly consistent across each modality with the highest during hemodialysis (5.53 mL/min), followed by hemodiafiltration (4.99 mL/min), and hemofiltration (3.94 mL/min). Percent drug remaining within the control samples (93.1%) remained consistent across each experiment, indicating negligible degradation within the blood. CONCLUSIONS: The results of this analysis are the first to demonstrate that large molecule therapeutic proteins such as anakinra, are removed from plasma with modern CRRT technology. Current dosing recommendations for patients with severe renal impairment may result in subtherapeutic anakinra concentrations in those receiving CRRT.

Evaluation and comparison of pharmacokinetic profiles and safety of two extended-release buprenorphine formulations in common marmosets (Callithrix jacchus).

While sustained-release buprenorphine (BSR) is used as a long-lasting opioid analgesic in common marmosets (Callithrix jacchus), there are no published studies on pharmaceutical-grade extended-release buprenorphine options such as Ethiqa XR (EXR) for this species. However, BSR is a compounded product and has been reported to cause injection site reactions in multiple species, including marmosets. Additionally, now with the availability of EXR, a pharmaceutical-grade veterinary product, the use of BSR in laboratory animals is not compliant with the Guide for the Care and Use of Laboratory Animals (Guide) unless scientifically justified and approved by the IACUC. We compared pharmacokinetic and safety profiles of BSR (0.15 mg/kg) and EXR (0.1-0.2 mg/kg) administered subcutaneously to adult marmosets. Blood was collected by venipuncture of the saphenous vein at multiple time points (0.25-72 h) and analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). EXR between 0.1 and 0.2 mg/kg resulted in a dose-dependent increase in Cmax (1.43-2.51 ng/mL) and were not statistically different from BSR (1.82 ng/mL). Tmax, lambdaz, and t1/2 were not statistically different between formulations. Mean plasma buprenorphine concentrations for BSR and EXR exceeded the therapeutic threshold (0.1 ng/mL) within 0.25 h and lasted for > 72 h. Mild sedation, but neither respiratory depression nor ataxia, was observed for both formulations. BSR injection sites had significantly higher histopathological scores compared to EXR. Video recordings for monitoring drug-induced behavioral changes showed increased animal activity levels after BSR and EXR versus saline controls. Norbuprenorphine, a buprenorphine metabolite associated with respiratory depression, was detected in the plasma after BSR and EXR administration as well as by in vitro liver microsome assays. In conclusion, we recommend using EXR over BSR as a long-lasting buprenorphine analgesic in marmosets because EXR is a pharmaceutical-grade formulation that is compliant with FDA guidelines and the Guide as well as exhibits comparable PK and safety profiles as BSR.

Intravenous Magnesium: Prompt Use for Asthma in Children Treated in the Emergency Department (IMPACT-ED): Protocol for a Multicenter Pilot Randomized Controlled Trial.

BACKGROUND: Children managed for asthma in an emergency department (ED) may be less likely to be hospitalized if they receive intravenous magnesium sulfate (IVMg). Asthma guidelines recommend IVMg for severely sick children but note a lack of evidence to support this recommendation. All previous trials of IVMg in children with asthma have been too small to answer whether IVMg is effective and safe. A few major questions remain about IVMg. First, it has not been tested early in the course of ED treatment, when the impact on hospitalization would be greatest. Second, the clinical impact of hypotension, a known adverse effect of IVMg, has not been well characterized in previous research. Third, no trials have compared different IVMg doses or serial serum magnesium (total and ionized) concentrations to optimize dosing, so the most effective dose is unknown. A large, conclusive, randomized, placebo-controlled clinical trial of IVMg might be challenging due to the need to enroll and complete study procedures quickly, a lack of understanding of blood pressure changes after IVMg, and a lack of pharmacologic information to guide the optimal doses of IVMg to be tested. Therefore, a pilot study to inform the above gaps is warranted before conducting a definitive trial. OBJECTIVE: The objectives of this study are to (1) demonstrate the feasibility of enrolling children with severe acute asthma in the ED in a multicenter, randomized controlled trial of a placebo, low-dose IVMg, or high-dose IVMg; (2) demonstrate the feasibility of timely delivery of study medication, assessment of blood pressure, and evaluation of adverse events in a standardized protocol; and (3) externally validate a previously constructed pharmacokinetic model and develop a combined pharmacokinetic/pharmacodynamic model for IVMg using magnesium (total and ionized) serum concentrations and their correlation with measures of efficacy and safety. METHODS: This pilot trial tests procedures and gathers information to plan a definitive trial. The pilot trial will enroll as many as 90 children across 3 sites, randomize each child to 1 of 3 study arms, measure blood pressure frequently, and collect 3 blood samples from each participant with corresponding clinical asthma scores. RESULTS: The project was funded by the National Heart, Lung, and Blood Institute (1 R34HL152047-2) in March 2022. Enrollment began in September 2022, and 43 children have been enrolled as of April 2023. We will submit the results for publication in late 2023. CONCLUSIONS: The results of this study will guide the planning of a large, definitive, multicenter trial powered to evaluate if IVMg reduces hospitalization. Blood pressure measurements will inform a monitoring plan for the larger trial, and blood samples and asthma scores will be used to validate pharmacologic models to select the optimal dose of IVMg to be evaluated in the definitive trial. TRIAL REGISTRATION: ClinicalTrials.gov NCT05166811; https://clinicaltrials.gov/ct2/show/NCT05166811. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/48302.

External assessment and refinement of a population pharmacokinetic model to guide tacrolimus dosing in pediatric heart transplant.

STUDY OBJECTIVE: The immunosuppressant tacrolimus is a first-line agent to prevent graft rejection following pediatric heart transplant; however, it suffers from extensive inter-patient variability and a narrow therapeutic window. Personalized tacrolimus dosing may improve transplant outcomes by more efficiently achieving and maintaining therapeutic tacrolimus concentrations. We sought to externally validate a previously published population pharmacokinetic (PK) model that was constructed with data from a single site. DATA SOURCE: Data were collected from Seattle, Texas, and Boston Children's Hospitals, and assessed using standard population PK modeling techniques in NONMEMv7.2. MAIN RESULTS: While the model was not successfully validated for use with external data, further covariate searching identified weight (p < 0.0001 on both volume and elimination rate) as a model-significant covariate. This refined model acceptably predicted future tacrolimus concentrations when guided by as few as three concentrations (median prediction error = 7%; median absolute prediction error = 27%). CONCLUSION: These findings support the potential clinical utility of a population PK model to provide personalized tacrolimus dosing guidance.

Pharmacokinetics of intranasal amiloride in healthy volunteers.

Anxiety and panic disorders are the most common mental illnesses in the United States and lack effective treatment options. Acid-sending ion channels (ASICs) in the brain were shown to be associated with fear conditioning and anxiety responses and therefore are potential targets for treating panic disorder. Amiloride is an inhibitor of the ASICs in the brain and was shown to reduce panic symptoms in preclinical animal models. An intranasal formulation of amiloride will be highly beneficial to treat acute panic attacks due to advantages such as the rapid onset of action and patient compliance. The aim of this single-center, open-label trial was to evaluate the basic pharmacokinetics (PKs) and safety of amiloride after intranasal administration in healthy human volunteers at three doses (0.2, 0.4, and 0.6 mg). Amiloride was detected in plasma within 10 min of intranasal administration and showed a biphasic PK profile with an initial peak within 10 min of administration followed by a second peak between 4 and 8 h of administration. The biphasic PKs indicate an initial rapid absorption via the nasal pathway and later slower absorption by non-nasal pathways. Intranasal amiloride exhibited a dose-proportional increase in the area under the curve and did not exhibit any systemic toxicity. These data indicate that intranasal amiloride is rapidly absorbed and safe at the doses evaluated and can be further considered for clinical development as a portable, rapid, noninvasive, and nonaddictive anxiolytic agent to treat acute panic attacks.

Cannabis Use Is Associated With Decreased Antiretroviral Therapy Adherence Among Older Adults With HIV.

Background: Conflicting evidence exists on the impact of cannabis use on antiretroviral therapy (ART) adherence among people with human immunodeficiency virus (PWH). We leveraged data collected among older PWH to characterize longitudinal associations between cannabis use and ART adherence. Methods: AIDS Clinical Trials Group (ACTG) A5322 study participants were categorized as <100% (≥1 missed dose in past 7 days) or 100% (no missed doses) ART adherent. Participants self-reported current (past month), intermittent (past year but not past month), and no cannabis (in past year) use at each study visit. Generalized linear models using generalized estimating equations were fit and inverse probability weighting was used to adjust for time-varying confounders and loss to follow-up. Results: Among 1011 participants (median age, 51 years), 18% reported current, 6% intermittent, and 76% no cannabis use at baseline; 88% reported 100% ART adherence. Current cannabis users were more likely to be <100% adherent than nonusers (adjusted risk ratio [aRR], 1.53 [95% CI, 1.11-2.10]). There was no association between ART adherence and current versus intermittent (aRR, 1.39 [95% CI, .85-2.28]) or intermittent versus no cannabis use (aRR, 1.04 [95% CI, .62-1.73]). Conclusions: Among a cohort of older PWH, current cannabis users had a higher risk of <100% ART adherence compared to nonusers. These findings have important clinical implications as suboptimal ART adherence is associated with ART drug resistance, virologic failure, and elevated risk for mortality. Further research is needed to elucidate the mechanisms by which cannabis use decreases ART adherence in older PWH and to advance the development of more efficacious methods to mitigate nonadherence in this vulnerable population.

Evaluating the efficacy of prototype antiseizure drugs using a preclinical pharmacokinetic approach.

OBJECTIVE: Pharmacokinetics (PK) of a drug drive its exposure, efficacy, and tolerability. A thorough preclinical PK assessment of antiseizure medications (ASMs) is therefore essential to evaluate the clinical potential. We tested protection against evoked seizures of prototype ASMs in conjunction with analysis of plasma and brain PK as a proof-of-principle study to enhance our understanding of drug efficacy and duration of action using rodent seizure models. METHODS: In vivo seizure protection assays were performed in adult male CF-1 mice and Sprague Dawley rats. Clobazam (CLB), N-desmethyl CLB (NCLB), carbamazepine (CBZ), CBZ-10,11-epoxide (CBZE), sodium valproate (VPA), and levetiracetam (LEV) concentrations were quantified in plasma and brain using liquid chromatography-tandem mass spectrometry. Mean concentrations of each analyte were calculated and used to determine PK parameters via noncompartmental analysis in Phoenix WinNonLin. RESULTS: NCLB concentrations were approximately 10-fold greater than CLB in mice. The antiseizure profile of CLB was partially sustained by NCLB in mice. CLB concentrations were lower in rats than in mice. CBZE plasma exposures were approximately 70% of CBZ in both mice and rats, likely contributing to the antiseizure effect of CBZ. VPA showed a relatively short half-life in both mice and rats, which correlated with a sharp decline in efficacy. LEV had a prolonged brain and plasma half-life, associated with a prolonged duration of action in mice. SIGNIFICANCE: The study demonstrates the utility of PK analyses for understanding the seizure protection time course in mice and rats. The data indicate that distinct PK profiles of ASMs between mice and rats likely drive differences in drug efficacy between rodent models.

Pre-clinical safety and therapeutic efficacy of a plant-based alkaloid in a human colon cancer xenograft model.

A high-throughput drug screen revealed that veratridine (VTD), a natural plant alkaloid, induces expression of the anti-cancer protein UBXN2A in colon cancer cells. UBXN2A suppresses mortalin, a heat shock protein, with dominant roles in cancer development including epithelial-mesenchymal transition (EMT), cancer cell stemness, drug resistance, and apoptosis. VTD-dependent expression of UBXN2A leads to the deactivation of mortalin in colon cancer cells, making VTD a potential targeted therapy in malignant tumors with high levels of mortalin. VTD was used clinically for the treatment of hypertension in decades past. However, the discovery of newer antihypertensive drugs and concerns over potential neuro- and cardiotoxicity ended the use of VTD for this purpose. The current study aims to determine the safety and efficacy of VTD at doses sufficient to induce UBXN2A expression in a mouse model. A set of flow-cytometry experiments confirmed that VTD induces both early and late apoptosis in a dose-dependent manner. In vivo intraperitoneal (IP) administration of VTD at 0.1 mg/kg every other day (QOD) for 4 weeks effectively induced expression of UBXN2A in the small and large intestines of mice. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) assays on tissues collected from VTD-treated animals demonstrated VTD concentrations in the low pg/mg range. To address concerns regarding neuro- and cardiotoxicity, a comprehensive set of behavioral and cardiovascular assessments performed on C57BL/6NHsd mice revealed that VTD generates no detectable neurotoxicity or cardiotoxicity in animals receiving 0.1 mg/kg VTD QOD for 30 days. Finally, mouse xenograft experiments in athymic nude mice showed that VTD can suppress tumor growth. The main causes for the failure of experimental oncologic drug candidates are lack of sufficient safety and efficacy. The results achieved in this study support the potential utility of VTD as a safe and efficacious anti-cancer molecule.

Remdesivir and GS-441524 Extraction by Ex Vivo Extracorporeal Life Support Circuits.

Patients with severe, COVID-related multi-organ failure often require extracorporeal life support (ECLS) such as extracorporeal membrane oxygenation (ECMO) or continuous renal replacement therapy (CRRT). An ECLS can alter drug exposure via multiple mechanisms. Remdesivir (RDV) and its active metabolite GS-441524 are likely to interact with ECLS circuits, resulting in lower than expected exposures. We evaluated circuit-drug interactions in closed loop, ex vivo ECMO and CRRT circuits. We found that mean (standard deviation) recovery of RDV at 6 hours after dosing was low in both the ECMO (33.3% [2.0]) and CRRT (3.5% [0.4]) circuits. This drug loss appears to be due primarily to drug adsorption by the circuit materials and potentially due to metabolism in the blood. GS-441524 recovery at 6 hours was high in the ECMO circuit 75.8% (16.5); however, was not detectable at 6 hours in the CRRT circuit. Loss in the CRRT circuit appears to be due primarily to efficient hemodiafiltration. The extent of loss for both molecules, especially in CRRT, suggests that in patients supported with ECMO and CRRT, RDV dosing adjustments are needed.

Dronabinol Prescribing and Exposure Among Children and Young Adults Diagnosed with Cancer.

Purpose: The therapeutic utility of Cannabis in cancer is a topic of intense interest. Dronabinol is synthetic Δ9-tetrahydrocannabinol (THC), the primary psychoactive component of Cannabis sativa, and is approved for treating refractory chemotherapy-induced nausea and vomiting. Little is known about dronabinol prescribing in children and young adults, and no published concentration data are available. This study evaluated national level dronabinol use and assessed concentrations of THC and its primary metabolites in patients with cancer <27 years of age prescribed dronabinol. Methods: Observational review of records from the Pediatric Health Information System (PHIS) and a regional network of hospitals in the Intermountain West, including a tertiary care children's hospital, Primary Children's Hospital (PCH), for inpatients <27 years of age prescribed dronabinol. Prospective blood samples were collected from children with cancer at PCH. Results: Across PHIS institutions, overall dronabinol prescribing aligned with the pharmacy records for those with cancer (p < 0.0001), and of these, 10.4% received dronabinol as inpatients. Blood collected within 72 hours of dronabinol administration was available from 10 children with a median age of 12.5 (range 6-17) years. Quantifiable concentrations were found in 4 (13%), 6 (20%), and 1 (3%) samples assayed for THC, 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (COOH-THC), and 11-hydroxy-Δ9-tetrahydrocannabinol (OH-THC), respectively. THC concentrations ranged between 0.100 and 0.128 ng/mL and were not associated with dose. Conclusion: Dronabinol prescribing appears exclusive to patients diagnosed with cancer, and its use has increased steadily in the past decade. In a small sample of children administered dronabinol, THC and metabolite concentrations were consistently low or undetectable.

Transient Receptor Potential Ankyrin-1 and Vanilloid-3 Differentially Regulate Endoplasmic Reticulum Stress and Cytotoxicity in Human Lung Epithelial Cells After Pneumotoxic Wood Smoke Particle Exposure.

This study investigated the roles of transient receptor potential (TRP) ankyrin-1 (TRPA1) and TRP vanilloid-3 (TRPV3) in regulating endoplasmic reticulum stress (ERS) and cytotoxicity in human bronchial epithelial cells (HBECs) treated with pneumotoxic wood smoke particulate matter (WSPM) and chemical agonists of each channel. Functions of TRPA1 and TRPV3 in pulmonary epithelial cells remain largely undefined. This study shows that TRPA1 activity localizes to the plasma membrane and endoplasmic reticulum (ER) of cells, whereas TRPV3 resides primarily in the ER. Additionally, treatment of cells using moderately cytotoxic concentrations of pine WSPM, carvacrol, and other TRPA1 agonists caused ERS as a function of both TRPA1 and TRPV3 activities. Specifically, ERS and cytotoxicity were attenuated by TRPA1 inhibition, whereas inhibiting TRPV3 exacerbated ERS and cytotoxicity. Interestingly, after treatment with pine WSPM, TRPA1 transcription was suppressed, whereas TRPV3 was increased. TRPV3 overexpression in HBECs conferred resistance to ERS and an attenuation of ERS-associated cell cycle arrest caused by WSPM and multiple prototypical ERS-inducing agents. Alternatively, short hairpin RNA-mediated knockdown of TRPV3, like the TRPV3 antagonist, exacerbated ERS. This study reveals previously undocumented roles for TRPA1 in promoting pathologic ERS and cytotoxicity elicited by pneumotoxic WSPM and TRPA1 agonists, and a unique role for TRPV3 in fettering pathologic facets of the integrated ERS response. SIGNIFICANCE STATEMENT: These findings provide new insights into how wood smoke particulate matter and other transient receptor potential ankyrin-1 (TRPA1) and transient receptor potential vanilloid-3 (TRPV3) agonists can affect human bronchial epithelial cells and highlight novel physiological and pathophysiological roles for TRPA1 and TRPV3 in these cells.

Supportive care medications coinciding with chemotherapy among children with hematologic malignancy.

Pharmacokinetic (PK) conflicts can arise between supportive care medications (SCM) and chemotherapy in children with hematologic malignancy (HM). In this retrospective study, medical records for children (28 days-18 years) diagnosed with HM and receiving an SCM antimicrobial were collected from a hospital network between 1 May 2000 and 31 December 2014. PK drug-gene associations were obtained from a curated pharmacogenomics database. Among 730 patients (median age of 7.5 (IQR 3.7-13.9) years), primarily diagnosed with lymphoid leukemia (52%), lymphoma (28%), or acute myeloid leukemia (16%), chemotherapy was administered in 2846 hospitalizations. SCM accounted for 90.5% (n = 448) of distinct drugs with 93% (n = 679) of children, receiving ≥5 different SCM/hospitalization. Same-day SCM/chemotherapeutic PK gene overlap occurred in 48.3% of hospitalizations and was associated with age (p = 0.026), number of SCM, HM subtype, surgery, and hematopoietic stem cell transplant (p < 0.0001). A high and variable SCM burden among children with HM receiving chemotherapy poses a risk for unanticipated PK conflicts.

Stability of Oxandrolone in Medium-Chain Triglyceride Oil and Pharmacokinetics Following Buccal Administration of the Extemporaneous Formulation in Neonates and Adults.

OBJECTIVES: Growth failure following surgical palliation of complex congenital heart defects (CHDs) is a prognosticator of poor outcomes. Many strategies for improving weight gain have been implemented in this population, with limited success. We recently described the potential of the anabolic steroid oxandrolone to improve weight gain following surgical repair of CHD when administered via a medium-chain triglyceride (MCT) oil suspension to the buccal mucosa. The current study evaluates the stability of oxandrolone in the MCT oil formulation, as well as the pharmacokinetics of oxandrolone when administered via buccal mucosa in both neonates and adults. METHODS: Stability was assessed by long-term storage of the preparation 1) at ambient conditions and 2) under photodegradative conditions for 3 days. Neonatal pharmacokinetic parameters were determined in a cohort of neonates following surgical CHD repair, whereas adult pharmacokinetics parameters were collected as part of a prospective study to evaluate the relative bioavailability of the oxandrolone in MCT oil formulation. RESULTS: We found that oxandrolone was stable in the MCT oil formulation for at least 1 month, although exposure to light hastened drug degradation. Both neonatal and adult oxandrolone pharmacokinetics were variable; however, oxandrolone in MCT oil was relatively well absorbed through the buccal mucosa (mean bioavailability = 62.5%). CONCLUSIONS: These data suggest that the variability in oxandrolone exposures is inherent to the drug, and not the formulation or route of administration. Combined, these data support further study of this novel oxandrolone in MCT oil formulation and its impact on growth following complex surgical repair of CHD in neonates.

Validation of an assay for quantifying ganciclovir in dried blood spots.

Valganciclovir (VGC) is an orally available mono-valyl ester pro drug of the nucleoside analog (NA) ganciclovir (GCV) used to treat cytomegalovirus (CMV). Congenital CMV infection in the newborn is associated with progressive sensorineural hearing loss; however, effective CMV therapy with VGC can improve audiologic outcomes. Ongoing studies to demonstrate the effect of VGC in this setting are hampered by a poor understanding of the pharmacology of VGC and GCV in newborns, and the low blood volumes that can be safely collected from this population. We describe a simple method for determining systemic GCV concentrations using dried blood spot (DBS) samples. GCV was extracted from a single 6 mm punch via sonication in methanol, then quantified using liquid chromatography-tandem mass spectrometry. The assay was accurate and precise in the dynamic range of 10-10,000 ng/mL. GCV concentrations determined in DBS agreed well with GCV concentrations observed in serum. The assay was successfully applied to patient samples, and will be used to support pharmacokinetic studies in an ongoing clinical trial of VGC in infants with CMV-mediated hearing loss.

Dose-escalation trial of budesonide in surfactant for prevention of bronchopulmonary dysplasia in extremely low gestational age high-risk newborns (SASSIE).

BACKGROUND: Initial trials of lung-targeted budesonide (0.25 mg/kg) in surfactant to prevent bronchopulmonary dysplasia (BPD) in premature infants have shown benefit; however, the optimal safe dose is unknown. METHODS: Dose-escalation study of budesonide (0.025, 0.05, 0.10 mg/kg) in calfactatant in extremely low gestational age neonates (ELGANs) requiring intubation at 3-14 days. Tracheal aspirate (TA) cytokines, blood budesonide concentrations, and untargeted blood metabolomics were measured. Outcomes were compared with matched infants receiving surfactant in the Trial Of Late SURFactant (TOLSURF). RESULTS: Twenty-four infants with mean gestational age 25.0 weeks and 743 g birth weight requiring mechanical ventilation were enrolled at mean age 6 days. Budesonide was detected in the blood of all infants with a half-life of 3.4 h. Of 11 infants with elevated TA cytokine levels at baseline, treatment was associated with sustained decrease (mean 65%) at all three dosing levels. There were time- and dose-dependent decreases in blood cortisol concentrations and changes in total blood metabolites. Respiratory outcomes did not differ from the historic controls. CONCLUSIONS: Budesonide/surfactant had no clinical respiratory benefit at any dosing levels for intubated ELGANs. One-tenth the dose used in previous trials had minimal systemic metabolic effects and appeared effective for lung-targeted anti-inflammatory action.