Model-Informed Precision Dosing Guidance of Ethosuximide Developed from a Randomized Controlled Clinical Trial of Childhood Absence Epilepsy

Ethosuximide was identified as the optimal option for new-onset childhood absence epilepsy (CAE) in a randomized, two-phase dose escalation comparative effectiveness trial of ethosuximide, lamotrigine, and valproic acid. However, 47% of ethosuximide initial monotherapy participants experienced short-term treatment failure. This study aimed to characterize the initial monotherapy ethosuximide exposure-response relationship and to propose model-informed precision dosing guidance. Dose titration occurred over a 16-20-week period until patients experienced seizure freedom or intolerable side effects. Subjects with initial monotherapy failure were randomized to one of the other two medications and dose escalation was repeated. A population pharmacokinetic model was created using plasma concentration data (n = 1,320), collected at 4-week intervals from 211 unique participants during both the initial and second monotherapy phases. A logistic regression analysis was performed on the initial monotherapy cohort (n = 103) with complete exposure-response data. Eighty-four participants achieved seizure freedom with a wide range of ethosuximide area under the curves (AUC) ranging from 420 to 2,420 μg·h/mL. AUC exposure estimates for achieving a 50% and 75% probability of seizure freedom were 1,027 and 1,489 μg·h/mL, respectively, whereas the corresponding cumulative frequency of intolerable adverse events was 11% and 16%. Monte Carlo Simulation indicated a daily dose of 40 and 55 mg/kg to achieve 50% and 75% probability of seizure freedom in the overall population, respectively. We identified the need for adjusted mg/kg dosing in different body weight cohorts. This ethosuximide proposed model-informed precision dosing guidance to achieve seizure freedom carries promise to optimize initial monotherapy success for patients with CAE.

Concomitant Ceftriaxone and Intravenous Calcium Therapy in Infants

OBJECTIVE

To determine if increased mortality could be detected with the administration of ceftriaxone and IV calcium in infants through an analysis of a large repository of electronic health records.

METHODS

Patients were split into 3 groups: 1) neonates, 2) infants, and 3) infants <1 year whose age was not specified. Deaths were classified into mutually exclusive categories based on the administration and timing of ceftriaxone and IV calcium. Crude death rates were calculated, and logistic regression modeling was used to calculate adjusted relative odds of death with associated covariates.

RESULTS

A total of 259,149 infants were identified. Of 79,038 neonates, the proportion of patients that received ceftriaxone and IV calcium within 48 hours who died was 3.8%, compared with 1.95% (IV calcium), 0.3% (ceftriaxone), 1.54% (IV fluids), and 2.03% (parenteral nutrition). For 102,456 infants, the proportions of deaths were 5.47% (ceftriaxone and IV calcium within 48 hours), 0.45% (IV calcium), 0.15% (ceftriaxone), 0.39% (IV fluids), and 5.5% (parenteral nutrition). Multivariate analysis showed increased odds of death in infants who received ceftriaxone and IV calcium within 48 hours, regardless of age, and propensity score-matched analysis showed a more than 2-fold increased risk for death.

CONCLUSIONS

The increased risk for death following ceftriaxone and IV calcium administration was noted not only in neonates, but among older infants as well.

How can we improve the safe use of herbal medicine and other natural products? A clinical pharmacologist mission

INTRODUCTION

Three major classes of natural products (NPs) for medicinal purposes or improving wellbeing are generally available in the US: conventional drugs of herbal origin, botanical drugs, and dietary supplements (DSs). Consumer consumption of DSs is growing annually. The U.S. FDA regulates conventional and botanical drugs for safety and efficacy; however, DSs are minimally regulated.

AREAS COVERED

This article will: i) highlight the importance of NP as a significant source of prescription drugs; ii) discuss differences in the regulation of conventional drugs of NP product, botanical drugs, and DSs; iii) discuss the safety and efficacy of DSs and iv) make recommendations for improvement of safety for minimally regulated NPs.

EXPERT OPINION

Toxicities associated with the use of NPs, including vitamins and DSs, are mainly due to excessive use and interactions with conventional drug(s) and may represent challenges for clinicians. Conventional and botanical-based prescription drugs are rarely associated with unknown toxicities. However, DSs are minimally regulated and can produce severe adverse effects. We believe that clinical pharmacologists can have a role in developing criteria for DS safety analysis. There is also the potential for a standardized NP stewardship program(s) and the development of NP policies and practices nationally and globally.

Tolerability of Aerosolized Versus Intravenous Pentamidine for Pneumocystis jirovecii Pneumonia Prophylaxis in Immunosuppressed Pediatric, Adolescent, and Young Adult Patients

OBJECTIVES

Pentamidine is an antifungal that is used alternatively to sulfamethoxazole-trimethoprim for the prophylaxis and treatment of Pneumocystis jirovecii pneumonia (PJP). The primary objective of this study was to assess the tolerability of aerosolized versus intravenous pentamidine for PJP prophylaxis in pediatric, adolescent, and young adult immunosuppressed patients. Secondary objectives included comparing pentamidine formulation reaction to dosing frequency and diagnosis.

METHODS

This retrospective chart review used electronic medical record (EMR) data from patients at a tertiary care pediatric teaching institution from January 1, 2014, to January 1, 2017. Information used from the EMR included pentamidine dosing, ordering, and laboratory values. Inclusion criteria consisted of patients with a cancer diagnosis, hematopoietic stem cell transplant (HSCT) recipients, and renal transplant recipients who received pentamidine for PJP prophylaxis.

RESULTS

Ninety-six patients met inclusion criteria, of which 31 received aerosolized pentamidine. Ten of the 96 patients experienced a drug-related reaction to either aerosolized or intravenous pentamidine (p = 0.134). Nine of 10 patients who experienced a reaction received intravenous pentamidine versus 1 patient who received aerosolized pentamidine (p = 0.132). In those patients who reacted to pentamidine there was a higher incidence of reactions after subsequent administration (p = 0.039) and in patients with a blood cancer diagnosis (p = 0.042).

CONCLUSIONS

Data suggest that patients who receive aerosolized pentamidine may tolerate therapy better compared to intravenous administration. Additional studies involving larger numbers of pediatric, adolescent, and young adult patients are needed for stronger statistically significant clinical differences in tolerability of aerosolized versus intravenous pentamidine.

Pharmacokinetics of Clindamycin in Obese and Nonobese Children

Although obesity is prevalent among children in the United States, pharmacokinetic (PK) data for obese children are limited. Clindamycin is a commonly used antibiotic that may require dose adjustment in obese children due to its lipophilic properties. We performed a clindamycin population PK analysis using data from three separate trials. A total of 420 samples from 220 children, 76 of whom had a body mass index greater than or equal to the 95th percentile for age, were included in the analysis. Compared to other metrics, total body weight (TBW) was the most robust measure of body size. The final model included TBW and a sigmoidal maturation relationship between postmenstrual age (PMA) and clearance (CL): CL (liters/hour) = 13.8 × (TBW/70)0.75 × [PMA2.83/(39.52.83+PMA2.83)]; volume of distribution (V) was associated with TBW, albumin (ALB), and alpha-1 acid glycoprotein (AAG): V (liters) = 63.6 × (TBW/70) × (ALB/3.3)-0.83 × (AAG/2.4)-0.25 After accounting for differences in TBW, obesity status did not explain additional interindividual variability in model parameters. Our findings support TBW-based dosing for obese and nonobese children.

Dosage Adjustments Related to Young or Old Age and Organ Impairment

Differences in physiology related to young or old age and/or organ system impairment alter the absorption, distribution, metabolism, and excretion of many medications and consequently their effectiveness and toxicity. This module discusses common alterations in medication use and dosage that are required in the pediatric age group, in the elderly, and in patients with renal or hepatic disease.

Reduced Sensitivity to Charge Noise in Semiconductor Spin Qubits via Symmetric Operation

We demonstrate improved operation of exchange-coupled semiconductor quantum dots by substantially reducing the sensitivity of exchange operations to charge noise. The method involves biasing a double dot symmetrically between the charge-state anticrossings, where the derivative of the exchange energy with respect to gate voltages is minimized. Exchange remains highly tunable by adjusting the tunnel coupling. We find that this method reduces the dephasing effect of charge noise by more than a factor of 5 in comparison to operation near a charge-state anticrossing, increasing the number of observable exchange oscillations in our qubit by a similar factor. Performance also improves with exchange rate, favoring fast quantum operations.

Longitudinal assessment of bone growth and development in a facility-based population of young adults with cerebral palsy

AIM

Osteoporosis is a significant clinical problem in persons with moderate to severe cerebral palsy (CP), causing fractures with minimal trauma. Over the past decade, most studies examining osteoporosis and CP have been cross-sectional in nature, focused exclusively on children and adolescents and only involving one evaluation of bone mineral density (BMD). The purpose of this study was to assess BMD in a group including adults with CP, and changes in each individual's BMD over a 5- to 6-year period.

METHOD

The study group included 40 residents of a long-term care facility aged 6 to 26 years at the time of their initial evaluation. Twenty-one patients (52.5%) were male, 35 (88%) were white, and 38 (95%) were in Gross Motor Function Classification System level V. BMD was assessed by dual-energy X-ray absorptiometry on the right and left distal femurs for three distinct regions of interest.

RESULTS

Five residents had a fracture that occurred during the study period; this represented a fracture rate of 2.1% per year in the study group. Longitudinally, annualized change in the median BMD was 0.7% to 1.0% per year in the different regions of the distal femur, but ranged widely among the study group, with both increases and decreases in BMD. Increase in BMD over time was negatively correlated with age and positively correlated with change in weight.

INTERPRETATION

Changes in BMD over time in profoundly involved persons with CP can range widely, which is important to recognize when evaluating potential interventions to improve BMD. Age and changes in body weight appear the most relevant factors.

Serum adipocytokines and adipose weight gain: a pilot study in adolescent females initiating depot medroxyprogesterone acetate

OBJECTIVE

To evaluate whether serum adipocytokine concentrations, controlling for baseline adiposity, are predictive of adipose weight gain in adolescents initiating depot medroxyprogesterone acetate (DMPA).

METHODS

Percent body fat was measured at baseline and 6 months. Baseline serum adipocytokine concentrations were quantified.

RESULTS

Mean percent body fat was 31.6% (±7.6) at baseline and 33.5% (±7.6) at 6 months. In multivariable linear regression modeling (adjusted for baseline percent body fat), Hispanic ethnicity and baseline serum adiponectin concentration were inversely associated (p≤.05) with absolute change in percent body fat at 6 months.

CONCLUSIONS

Serum adiponectin concentration may be useful for assessing risk of DMPA-associated adipose gains.

The National Environmental Respiratory Center (NERC) experiment in multi-pollutant air quality health research: II. Comparison of responses to diesel and gasoline engine exhausts, hardwood smoke and simulated downwind coal emissions

The NERC Program conducted identically designed exposure-response studies of the respiratory and cardiovascular responses of rodents exposed by inhalation for up to 6 months to diesel and gasoline exhausts (DE, GE), wood smoke (WS) and simulated downwind coal emissions (CE). Concentrations of the four combustion-derived mixtures ranged from near upper bound plausible to common occupational and environmental hotspot levels. An "exposure effect" statistic was created to compare the strengths of exposure-response relationships and adjustments were made to minimize false positives among the large number of comparisons. All four exposures caused statistically significant effects. No exposure caused overt illness, neutrophilic lung inflammation, increased circulating micronuclei or histopathology of major organs visible by light microscopy. DE and GE caused the greatest lung cytotoxicity. WS elicited the most responses in lung lavage fluid. All exposures reduced oxidant production by unstimulated alveolar macrophages, but only GE suppressed stimulated macrophages. Only DE retarded clearance of bacteria from the lung. DE before antigen challenge suppressed responses of allergic mice. CE tended to amplify allergic responses regardless of exposure order. GE and DE induced oxidant stress and pro-atherosclerotic responses in aorta; WS and CE had no such effects. No overall ranking of toxicity was plausible. The ranking of exposures by number of significant responses varied among the response models, with each of the four causing the most responses for at least one model. Each exposure could also be deemed most or least toxic depending on the exposure metric used for comparison. The database is available for additional analyses.

Targeted liquid chromatography-mass spectrometry analysis of serum acylcarnitines in acetaminophen toxicity in children

AIM

Long-chain acylcarnitines have been postulated to be sensitive biomarkers of acetaminophen (APAP)-induced hepatotoxicity in mouse models. In the following study, the relationship of acylcarnitines with other known indicators of APAP toxicity was examined in children receiving low-dose (therapeutic) and high-dose ('overdose' or toxic ingestion) exposure to APAP.

MATERIALS & METHODS

The study included three subject groups: group A (therapeutic dose, n = 187); group B (healthy controls, n = 23); and group C (overdose, n = 62). Demographic, clinical and laboratory data were collected for each subject. Serum samples were used for measurement of APAP protein adducts, a biomarker of the oxidative metabolism of APAP and for targeted metabolomics analysis of serum acylcarnitines using ultra performance liquid chromatography-triple-quadrupole mass spectrometry.

RESULTS

Significant increases in oleoyl- and palmitoyl-carnitines were observed with APAP exposure (low dose and overdose) compared with controls. Significant increases in serum ALT, APAP protein adducts and acylcarnitines were observed in overdose children that received delayed treatment (time to treatment from overdose >24 h) with the antidote N-acetylcysteine. Time to peak APAP protein adducts in serum was shorter than that of the acylcarnitines and serum ALT.

CONCLUSION

Perturbations in long-chain acylcarnitines in children with APAP toxicity suggest that mitochrondrial injury and associated impairment in the β-oxidation of fatty acids are clinically relevant as biomarkers of APAP toxicity.

A pilot study of depot medroxyprogesterone acetate pharmacokinetics and weight gain in adolescent females

OBJECTIVE

To explore the relationship between medroxyprogesterone acetate (MPA) pharmacokinetic (PK) parameter estimates and weight gain.

STUDY DESIGN

Prospective study of adolescents (N=40; age 12-21 years) initiating DMPA. PK parameters were calculated: maximum MPA concentration (Cmax, ng/mL), time to Cmax (Tmax, days) and elimination rate constant (ng/mL/day). Optimal PK cut points were determined for predicting body mass index (BMI) increase ≥10%.

RESULTS

Cmax <2.88 ng/mL and elimination rate constant <0.021 ng/mL/day were associated (p<.05) with BMI increase ≥10%. Elimination rate constant was most predictive of weight gain.

CONCLUSIONS

PK evaluation may help identify adolescents at risk of excessive DMPA-associated weight gain.

Aerosolised 5-azacytidine suppresses tumour growth and reprogrammes the epigenome in an orthotopic lung cancer model

BACKGROUND

Epigenetic silencing by promoter methylation and chromatin remodelling affects hundreds of genes and is a causal event for lung cancer. Treatment of patients with low doses of the demethylating agent 5-azacytidine in combination with the histone deacetylase inhibitor entinostat has yielded clinical responses. The subcutaneous dosing route for consecutive days and reduced bioavailability of 5-azacytidine because of inactivation by cytidine deaminase may limit the expansion of epigenetic therapy into Phase III trials. To mitigate these barriers, an aerosol of 5-azacytidine was generated and characterised.

METHODS

The effect of aerosol vs systemic delivery of 5-azacytidine on tumour burden and molecular response of engrafted lung tumours in the nude rat was compared.

RESULTS

Pharmacokinetics revealed major improvement in the half-life of 5-azacytidine in lung tissue with aerosol delivery. Aerosolised 5-azacytidine significantly reduced lung tumour burden and induced global demethylation of the epigenome at one-third of the comparable effective systemic dose. High commonality for demethylation of genes was seen in tumours sampled throughout lung lobes and across treated animals receiving the aerosolised drug.

CONCLUSION

Collectively, these findings show that aerosolised 5-azacytidine targets the lung, effectively reprogrammes the epigenome of tumours, and is a promising approach to combine with other drugs for treating lung cancer.

Valproic Acid and topiramate induced hyperammonemic encephalopathy in a patient with normal serum carnitine

A 17-year-old female developed hyperammonemic encephalopathy 2 weeks after valproic acid (VPA), 500 mg twice a day, was added to her regimen of topiramate (TPM), 200 mg twice a day. She presented to the emergency department (ED) with altered mental status, hypotension, bradycardia, and lethargy. Laboratory analysis showed mild non-anion gap hyperchloremic acidosis, serum VPA concentration of 86 mg/L, and urine drug screen result that was positive for marijuana. She was admitted to the pediatric intensive care unit for persistent symptoms, prolonged QTc, and medical history. Blood ammonia concentrations were obtained because of her persistent altered mental status, initially 94 μmol/L and a peak of 252 μmol/L. A serum carnitine profile was obtained at the time of hyperammonemia and was found to be normal (results were available postdischarge). VPA and TPM were discontinued on day 1 and day 2, respectively, as the patient's blood ammonia concentration remained elevated. On day 3, her mental status had returned to baseline, and blood ammonia concentrations trended downward; by day 4 her blood ammonia concentration was 23 μmol/L. VPA has been associated with numerous side effects including hyperammonemia and encephalopathy. Recently, drug interactions with TPM and VPA have been reported; however, serum carnitine concentrations have not been available. We discuss the possible mechanisms that VPA and TPM may affect serum ammonia and carnitine concentrations and the use of levocarnitine for patients or treating toxicity.

Behavioral effects of acclimatization to restraint protocol used for awake animal imaging

Functional MRI in awake rats involves acclimatization to restraint to minimize motion. We designed a study to examine the effects of an acclimatization protocol (5 days of restraint, 60 min per day) on the emission of 22-kHz ultrasonic vocalizations and performance in a forced swim test (FST). Our results showed that USV calls are reduced significantly by days 3, 4 and 5 of acclimatization. Although the rats showed less climbing activity (and more immobility) in FST on day 5 compared to the 1st day of restraint acclimatization, the difference was not detected once the animals were given a 2-week hiatus. Overall, we showed that animals adapt to the restraint over a five-day period; however, restraint may introduce confounding behavioral outcomes that may hinder the interpretation of results derived from awake rat imaging. The present data warrants further testing of the effects of MRI restraint on behavior.

Measurements of quasiparticle tunneling dynamics in a band-gap-engineered transmon qubit

We have engineered the band gap profile of transmon qubits by combining oxygen-doped Al for tunnel junction electrodes and clean Al as quasiparticle traps to investigate energy relaxation due to quasiparticle tunneling. The relaxation time T1 of the qubits is shown to be insensitive to this band gap engineering. Operating at relatively low-E(J)/E(C) makes the transmon transition frequency distinctly dependent on the charge parity, allowing us to detect the quasiparticles tunneling across the qubit junction. Quasiparticle kinetics have been studied by monitoring the frequency switching due to even-odd parity change in real time. It shows the switching time is faster than 10  μs, indicating quasiparticle-induced relaxation has to be reduced to achieve T1 much longer than 100  μs.

A burn center paradigm to fulfill deferred consent public disclosure and community consultation requirements for emergency care research

INTRODUCTION

To fulfill Food and Drug Administration and Department of Health and Human Services emergency care research informed consent requirements, our burn center planned and executed a deferred consent strategy gaining Institutional Review Board (IRB) approval to proceed with the clinical study. These federal regulations dictate public disclosure and community consultation unique to acute care research.

OBJECTIVE

Our regional burn center developed and implemented a deferred consent public notification and community consultation paradigm appropriate for a burn study.

METHODS

Published accounts of deferred consent strategies focus on acute care resuscitation practices. We adapted those strategies to design and conduct a comprehensive public notification/community consultation plan to satisfy deferred consent requirements for burn center research.

RESULTS

To implement a robust media campaign we engaged the hospital's public relations department, distributed media materials, recruited hospital staff for speaking engagements, enlisted community volunteers, and developed initiatives to inform "hard-to-reach" populations. The hospital's IRB determined we fulfilled our obligation to notify the defined community.

CONCLUSION

Our communication strategy should provide a paradigm other burn centers may appropriate and adapt when planning and executing a deferred consent initiative.

Reversing the Myths Obstructing the Determination of Optimal Age- and Disease-Based Drug Dosing in Pediatrics

The need for critical, well-designed comprehensive clinical pharmacology research in pediatrics that encompasses the age continuum, from the most premature infant through adolescence, may be more important today than ever. New drug regimens often require greater adherence to specific dose guidelines to maximize efficacy and minimize toxic potential. The climate that allowed the propagation of the “therapeutic orphan” concept is now mostly of historical perspective. Nevertheless, the negative impact of this concept continues to linger due to continued propagation of many, now outdated myths surrounding the effective study of optimal drug dosing in pediatrics. Advances in clinical medicine combined with the advances in study design, sampling, and analysis has dramatically improved the paradigm for clinical pharmacology research in infants and children. Capitalizing upon and thoughtfully using these many advances while dispelling these myths will result in greater research focused on optimal drug therapy in pediatric practice.

Reversing the myths obstructing the determination of optimal age- and disease-based drug dosing in pediatrics

The need for critical, well-designed comprehensive clinical pharmacology research in pediatrics that encompasses the age continuum, from the most premature infant through adolescence, may be more important today than ever. New drug regimens often require greater adherence to specific dose guidelines to maximize efficacy and minimize toxic potential. The climate that allowed the propagation of the "therapeutic orphan" concept is now mostly of historical perspective. Nevertheless, the negative impact of this concept continues to linger due to continued propagation of many, now outdated myths surrounding the effective study of optimal drug dosing in pediatrics. Advances in clinical medicine combined with the advances in study design, sampling, and analysis has dramatically improved the paradigm for clinical pharmacology research in infants and children. Capitalizing upon and thoughtfully using these many advances while dispelling these myths will result in greater research focused on optimal drug therapy in pediatric practice.

Cocooning: influenza vaccine for parents and caregivers in an urban, pediatric medical home

OBJECTIVE

To determine the acceptance of influenza vaccination by caregivers of children at risk for complications of influenza, if their annual vaccination could be administered by their child's pediatric caregivers during their child's office visit.

RESULTS

During the 2008-2009 influenza season, 474 caregivers were approached, and 336 (70.9%) agreed to participate; 44 were excluded because they had already received their seasonal influenza vaccination, leaving 292 participants. Most were female (80.8%), the child's mother (68.5%), and African American (58.6%). In all, 250 of the 292 participants agreed to receive the influenza vaccine in the pediatrician's office. There were no clinically relevant demographic differences between those who received the vaccine and those who did not. The change in vaccination rate for the group of participants from the previous year was significant (23.7% to 85.6%; P < .001).

CONCLUSION

Caregivers of at-risk pediatric patients are accepting of influenza vaccination from pediatric practitioners while attending their child's pediatric clinic visit.

Preparation and measurement of three-qubit entanglement in a superconducting circuit

Traditionally, quantum entanglement has been central to foundational discussions of quantum mechanics. The measurement of correlations between entangled particles can have results at odds with classical behaviour. These discrepancies grow exponentially with the number of entangled particles. With the ample experimental confirmation of quantum mechanical predictions, entanglement has evolved from a philosophical conundrum into a key resource for technologies such as quantum communication and computation. Although entanglement in superconducting circuits has been limited so far to two qubits, the extension of entanglement to three, eight and ten qubits has been achieved among spins, ions and photons, respectively. A key question for solid-state quantum information processing is whether an engineered system could display the multi-qubit entanglement necessary for quantum error correction, which starts with tripartite entanglement. Here, using a circuit quantum electrodynamics architecture, we demonstrate deterministic production of three-qubit Greenberger-Horne-Zeilinger (GHZ) states with fidelity of 88 per cent, measured with quantum state tomography. Several entanglement witnesses detect genuine three-qubit entanglement by violating biseparable bounds by 830 ± 80 per cent. We demonstrate the first step of basic quantum error correction, namely the encoding of a logical qubit into a manifold of GHZ-like states using a repetition code. The integration of this encoding with decoding and error-correcting steps in a feedback loop will be the next step for quantum computing with integrated circuits.

High-fidelity readout in circuit quantum electrodynamics using the Jaynes-Cummings nonlinearity

We demonstrate a qubit readout scheme that exploits the Jaynes-Cummings nonlinearity of a superconducting cavity coupled to transmon qubits. We find that, in the strongly driven dispersive regime of this system, there is the unexpected onset of a high-transmission "bright" state at a critical power which depends sensitively on the initial qubit state. A simple and robust measurement protocol exploiting this effect achieves a single-shot fidelity of 87% using a conventional sample design and experimental setup, and at least 61% fidelity to joint correlations of three qubits.

Assessment of serum creatine kinase among adolescent patients following jimsonweed (Datura stramonium) and moonflower (Datura inoxia) ingestions: a review of 11 cases

INTRODUCTION

Datura stramonium (DS) (jimsonweed) is well known for its abuse potential for hallucinogenic effects and Datura inoxia (DI) (moonflower) has been abused for similar effects. To our knowledge, only one case report describes rhabdomyolysis in association with DS or DI ingestion.

CASE IDENTIFICATION AND DETAILS

Patient hospital charts were retrospectively screened from January 1, 2002 to December 31, 2007 to identify patients with qualifying ICD-9 codes for toxic plant ingestions. We report on 11 patient cases of DS/DI ingestions in which serum creatine kinase (CK) concentrations were monitored. These admissions occurred at our hospital over a 6-year period. Serum CK concentrations ranged from 72 to 70,230 U/L. Only three patients had serum CK concentrations greater than 1,000 U/L. One patient with a peak concentration of 70,230 U/L and a positive myoglobinuria was diagnosed with rhabdomyolysis.

DISCUSSION

Based on our review of the literature and these cases, it is possible that serum CK concentrations may be elevated more frequently than previously realized. The clinical significance of this abnormal laboratory value is uncertain with the majority of patients remaining asymptomatic without any clinical evidence of rhabdomyolysis.

Variations in amoxicillin pharmacokinetic/pharmacodynamic parameters may explain treatment failures in acute otitis media

Pharmacokinetic/pharmacodynamic (PK/PD) modeling and Monte Carlo simulations suggest that amoxicillin should rarely fail as therapy for Streptococcus pneumoniae and Haemophilus influenzae acute otitis media (AOM) infections except when the S. pneumoniae are highly penicillin resistant or the H. influenzae are beta-lactamase producing. However, important and not infrequent exceptions to this expectation have been described. The objective of this review was to define the biologic variations in amoxicillin PK/PD parameters for the treatment of AOM in children and assess whether these variations could explain why the commonly employed amoxicillin PK/PD model is imperfect in predicting outcome for every patient in this clinical setting. To this end, a literature search of MEDLINE (1966-2006) and EMBASE (1974-2006) was conducted to identify studies that evaluated ampicillin or amoxicillin intestinal absorption, serum concentrations, and/or middle ear fluid (MEF) concentrations. Analysis of studies identified for review showed that the intestinal bioavailability of amoxicillin depends on passive diffusion and a saturable 'pump' mechanism that produces variable serum concentrations of the antibacterial agent. Indeed, substantial differences from patient to patient in serum (5- to 30-fold) and MEF (up to 20-fold) concentrations of amoxicillin occur following oral administration, and 15-35% of children have no detectable amoxicillin in MEF. These findings suggest that variability in PK/PD parameters may impact amoxicillin concentrations in serum and MEF, possibly explaining some AOM treatment failures.

Controlled clinical trial of zolpidem for the treatment of insomnia associated with attention-deficit/ hyperactivity disorder in children 6 to 17 years of age

OBJECTIVE

The goal was to evaluate the hypnotic efficacy of zolpidem at 0.25 mg/kg per day (maximum of 10 mg/day), compared with placebo, in children 6 through 17 years of age who were experiencing insomnia associated with attention-deficit/hyperactivity disorder.

METHODS

An 8-week, North American, multicenter, double-blind, placebo-controlled, parallel-group study was conducted. Patients underwent stratification according to age (6-11 years [N = 111] or 12-17 years [N = 90]) and were assigned randomly to receive treatment with the study drug or placebo (in a 2:1 ratio). The primary efficacy variable was latency to persistent sleep between weeks 3 and 6. Secondary efficacy variables also were assessed, and behavioral and cognitive components of attention-deficit/hyperactivity disorder were monitored. Safety was assessed on the basis of reports of adverse events, abnormal laboratory data, vital signs, and physical examination findings. The potential for next-day residual effects also was assessed.

RESULTS

The baseline-adjusted mean change in latency to persistent sleep at week 4 did not differ significantly between the zolpidem and placebo groups (-20.28 vs -21.27 minutes). However, differences favoring zolpidem were observed for the older age group in Clinical Global Impression scores at weeks 4 and 8. No next-day residual effects of treatment were associated with zolpidem, and no rebound phenomena occurred after treatment discontinuation. Central nervous system and psychiatric disorders were the most-frequent treatment-emergent adverse events (>5%) that were observed more frequently with zolpidem than with placebo; these included dizziness, headache, and hallucinations. Ten (7.4%) patients discontinued zolpidem treatment because of adverse events.

CONCLUSION

Zolpidem at a dose of 0.25 mg/kg per day to a maximum of 10 mg failed to reduce the latency to persistent sleep on polysomnographic recordings after 4 weeks of treatment in children and adolescents 6 through 17 years of age who had attention-deficit/hyperactivity disorder-associated insomnia.

The short-term safety and efficacy of fluoxetine in depressed adolescents with alcohol and cannabis use disorders: a pilot randomized placebo-controlled trial

BACKGROUND

The objective of this study was to examine whether fluoxetine was superior to placebo in the acute amelioration of depressive symptomatology in adolescents with depressive illness and a comorbid substance use disorder.

METHODS

Eligible subjects ages 12-17 years with either a current major depressive disorder (MDD) or a depressive disorder that were also suffering from a comorbid substance-related disorder were randomized to receive either fluoxetine or placebo in this single site, 8-week double-blind, placebo-controlled study. The primary outcome analysis was a random effects mixed model for repeated measurements of Children's Depression Rating Scale-Revised (CDRS-R) scores compared between treatment groups across time.

RESULTS

An interim analysis was performed after 34 patients were randomized. Based on the results of a futility analysis, study enrollment was halted. Twenty-nine males and 5 females were randomized to receive fluoxetine (n = 18) or placebo (n = 16). Their mean age was 16.5 (1.1) years. Overall, patients who received fluoxetine and placebo had a reduction in CDRS-R scores. However, there was no significant difference in mean change in CDRS-R total score in those subjects treated with fluoxetine and those who received placebo (treatment difference = 0.19, S.E. = 0.58, F = 0.14, p = .74). Furthermore, there was not a significant difference in rates of positive urine drug toxicology results between treatment groups at any post-randomization visit (F = 0.22, df = 1, p = 0.65). The main limitation of this study is its modest sample size and resulting low statistical power. Other significant limitations to this study include, but are not limited to, the brevity of the trial, high placebo response rate, limited dose range of fluoxetine, and the inclusion of youth who met criteria for depressive disorders other than MDD.

CONCLUSION

Fluoxetine was not superior to placebo in alleviating depressive symptoms or in decreasing rates of positive drug screens in the acute treatment of adolescents with depression and a concomitant substance use disorder.

Health Effects of Subchronic Exposure to Environmental Levels of Diesel Exhaust

Diesel exhaust is a public health concern and contributor to both ambient and occupational air pollution. As part of a general health assessment of multiple anthropogenic source emissions conducted by the National Environmental Respiratory Center (NERC), a series of health assays was conducted on rats and mice exposed to environmentally relevant levels of diesel exhaust. This article summarizes the study design and exposures, and reports findings on several general indicators of toxicity and carcinogenic potential. Diesel exhaust was generated from a commonly used 2000 model 5.9-L, 6-cylinder turbo diesel engine operated on a variable-load heavy-duty test cycle burning national average certification fuel. Animals were exposed to clean air (control) or four dilutions of whole emissions based on particulate matter concentration (30, 100, 300, and 1000 microg/m(3)). Male and female F344 rats and A/J mice were exposed by whole-body inhalation 6 h/day, 7 days/wk, for either 1 wk or 6 mo. Exposures were characterized in detail. Effects of exposure on clinical observations, body and organ weights, serum chemistry, hematology, histopathology, bronchoalveolar lavage, and serum clotting factors were mild. Significant exposure-related effects occurring in both male and female rats included decreases in serum cholesterol and clotting Factor VII and slight increases in serum gamma-glutamyl transferase. Several other responses met screening criteria for significant exposure effects but were not consistent between genders or exposure times and were not corroborated by related parameters. Carcinogenic potential as determined by micronucleated reticulocyte counts and proliferation of adenomas in A/J mice were unaffected by 6 mo of exposure. Parallel studies demonstrated effects on cardiac function and resistance to viral infection; however, the results reported here show few and only modest health hazards from subchronic or shorter exposures to realistic concentrations of contemporary diesel emissions.

Health effects of subchronic exposure to environmental levels of hardwood smoke

Hardwood smoke is a contributor to both ambient and indoor air pollution. As part of a general health assessment of multiple anthropogenic source emissions conducted by the National Environmental Respiratory Center, a series of health assays was conducted on rodents exposed to environmentally relevant levels of hardwood smoke. This article summarizes the study design and exposures, and reports findings on general indicators of toxicity, bacterial clearance, cardiac function, and carcinogenic potential. Hardwood smoke was generated from an uncertified wood stove, burning wood of mixed oak species. Animals were exposed to clean air (control) or dilutions of whole emissions based on particulate (30, 100, 300, and 1000 micromg/m3). F344 rats, SHR rats, strain A/J mice, and C57BL/6 mice were exposed by whole-body inhalation 6 h/day, 7 days/wk, for either 1 wk or 6 mo. Effects of exposure on general indicators of toxicity, bacterial clearance, cardiac function, and carcinogenic potential were mild. Exposure-related effects included increases in platelets and decreases in blood urea nitrogen and serum alanine aminotransferase. Several other responses met screening criteria for significant exposure effects but were not consistent between genders or exposure times and were not corroborated by related parameters. Pulmonary histopathology revealed very little accumulation of hardwood smoke particulate matter. Parallel studies demonstrated mild exposure effects on bronchoalveolar lavage parameters and in a mouse model of asthma. In summary, the results reported here show few and only modest health hazards from short-term to subchronic exposures to realistic concentrations of hardwood smoke.

Ankylosing spondylitis: an Australian experience

BACKGROUND

The purpose of this study was to characterize an Australian cohort of ankylosing spondylitis (AS) patients and examine predictors of important disease outcomes.

METHODS

Cross-sectional study of first visit data among patients referred to the Austin Spondylitis Clinic from rheumatology or general practices. We obtained clinical and laboratory data and validated composite indices through self-reported questionnaire.

RESULTS

Delay in AS diagnosis averaged 8.1 years and was higher among women and younger-onset disease. Cervicothoracic mobility was better in women although they showed more entheseal tender points and greater impairment of quality of life. Those with long-standing AS had similar disease activity to recent onset disease but had greater functional disability. Current smoking was associated with worse outcomes although there was no association between cumulative exposure and AS outcomes.

CONCLUSION

The clinical expression of AS in this first-described Australian cohort is similar to previously described cohorts. We observed greater cervicothoracic mobility and a higher enthesitis index among women perhaps contributing to longer delay to diagnosis.

Venlafaxine in the treatment of children and adolescents with attention-deficit/hyperactivity disorder

OBJECTIVE

The objectives of this pilot study were to explore the changes in symptom severity, tolerability, and the pharmacodynamics of venlafaxine treatment in youths with attention-deficit/hyperactivity disorder (ADHD).

METHODS

This was a 2-week, open-label, outpatient trial of venlafaxine in children and adolescents, ages 5-17 years, with ADHD. Three dosing strata, 0.5, 1.0, and 2.0 mg/kg per day, were examined. ADHD symptom severity and improvement assessments included the ADHD Rating Scale (ARS-IV) and the Clinical Global Impressions Scale (CGI). During this study, venlafaxine, O-desmethylvenlafaxine (ODV), norepinephrine, and serotonin concentrations were obtained.

RESULTS

Thirty-eight participants (33 males) were treated in this trial. Overall, parent-completed and teacher-completed ARS-IV total scores showed a statistically significant positive change at the end of the study when compared to baseline (p < 0.05). Significant increases in plasma venlafaxine concentrations were observed at day 15 when compared to day 8 (p = 0.04). In addition, plasma norepinephrine and serotonin concentrations were found to be significantly decreased from baseline at end of study (p < 0.05). Four patients ended participation in the study prematurely: lost to follow up (n = 2), withdrawal of consent (n = 1), and worsening of ADHD symptoms after 8 days of treatment (n = 1). There were no discontinuations due to other adverse events.

CONCLUSIONS

Venlafaxine appeared to offer some benefit and appears to be relatively safe for the short-term treatment of ADHD in this open-label trial. The pharmacodynamics of venlafaxine in youths are consistent with serotonergic and neuradrenergic modulation.

Double-blind, placebo-controlled trial of divalproex monotherapy in the treatment of symptomatic youth at high risk for developing bipolar disorder

OBJECTIVE

To determine if divalproex sodium was superior to placebo in the treatment of symptomatic youths who suffer from a bipolar spectrum disorder and who also have a parent with a diagnosis of a bipolar illness.

METHOD

Youths, ages 5 to 17 years, meeting DSM-IV criteria for bipolar disorder not otherwise specified (NOS) or cyclothymia who also had at least 1 biological parent with bipolar illness were randomly assigned in a double-blind fashion to receive treatment with either dival-proex sodium or placebo for up to 5 years. Study participation ended if the subject required additional clinical intervention, if the patient developed treatment-related adverse events, or if the participant was not adherent with study procedures. The primary outcome measure was time to study discontinuation for any reason. The study was conducted from August 1997 to April 2003.

RESULTS

Fifty-six youths with a mean (SD) age of 10.7 (3.1) years were randomly assigned and received either divalproex sodium (N = 29) or placebo (N = 27). In spite of statistical power of 80% to detect hazard ratios of 2.2 or larger, the treatment groups did not significantly differ in survival time for discontinuation for any reason (p = .93) or discontinuation due to a mood event (p = .55). Changes in mood symptom ratings and psychosocial functioning from baseline to study discontinuation did not differ between groups (most significant p > .14). However, both groups did show improvements in mood symptoms and psychosocial functioning over time (all p values < .002). One patient, from the placebo group, ended study participation due to an adverse event.

CONCLUSION

These results suggest that, although well tolerated, divalproex sodium does not produce clinically meaningful improvements in the treatment of symptomatic youths suffering from either bipolar NOS or cyclothymia who are at genetic risk for developing bipolar disorder.

Considerations in the rational design and conduct of phase I/II pediatric clinical trials: avoiding the problems and pitfalls

Over the past decade, there has been a heightened awareness of the need to include children in the drug development process. With this awareness has come an expansion of the infrastructure for conducting studies in children and an increase in the sponsorship of pediatric clinical trials. However, the growth in pediatric research has, in many cases, not been accompanied by an increase in the involvement of trained pediatric investigators when it comes to trial design and/or interpretation. Pediatric phase I/II protocols continue to span a spectrum from those that are carefully constructed to those that are poorly designed. This paper highlights the basic elements of phase I/II protocols that merit unique consideration when the clinical trial involves children. Illustrations are provided from our experience, which highlight problems that may arise when trials are not designed with the pediatric patient in mind.

Health effects of subchronic exposure to diesel-water-methanol emulsion emission

The U.S. Environmental Protection Agency's National Ambient Air Quality Standards for ozone and particulate matter (PM) require urban non-attainment areas to implement pollution-reduction strategies for anthropogenic source emissions. The type of fuel shown to decrease combustion emissions components versus traditional diesel fuel, is the diesel emulsion. The Lubrizol Corporation, in conjunction with Lovelace Respiratory Research Institute and several subcontracting laboratories, recently conducted a health assessment of the combustion emissions of PuriNOx diesel fuel emulsion (diesel-water-methanol) in rodents. Combustion emissions from either of two, 2002 model Cummins 5.9L ISB engines, were diluted with charcoal-filtered air to exposure concentrations of 125, 250 and 500 microg total PM/m3. The engines were operated on a continuous, repeating, heavy-duty certification cycle (U.S. Code of Federal Regulations, Title 40, Chapter I) using Rotella-T 15W-40 engine oil. Nitrogen oxide (NO) and PM were reduced when engines were operated on PuriNOx versus California Air Resources Board diesel fuel under these conditions. Male and female F344 rats were housed in Hazleton H2000 exposure chambers and exposed to exhaust atmospheres 6 h/day, five days/week for the first 11 weeks and seven days/week thereafter. Exposures ranged from 61 to 73 days depending on the treatment group. Indicators of general toxicity (body weight, organ weight, clinical pathology and histopathology), neurotoxicity (glial fibrillary acidic protein assay), genotoxicity (Ames assay, micronucleus, sister chromatid exchange), and reproduction and development were measured. Overall, effects observed were mild. Emulsion combustion emissions were not associated with neurotoxicity, reproductive/developmental toxicity, or in vivo genotoxicity. Small decreases in serum cholesterol in the 500-microg/m3 exposure group were observed. PM accumulation within alveolar macrophages was evident in all exposure groups. The latter findings are consistent with normal physiological responses to particle inhalation. Other statistically significant effects were present in some measured parameters of other exposed groups, but were not clearly attributed to emissions exposure. Positive mutagenic responses in several strains of Salmonella typhimurium were observed subsequent to treatment with emulsion emissions subfractions. Based on the cholesterol results, it can be concluded that the 250-microg/m3 exposure level was the no observed effect level. In general, biological findings in exposed rats and bacteria were consistent with exposure to petroleum diesel exhaust in the F344 rat and Ames assays.

A 26-week open-label study of quetiapine in children with conduct disorder

OBJECTIVE

The aim of this study was to describe the long-term safety and effectiveness of quetiapine in conduct disorder (CD).

METHODS

This was an 18-week outpatient follow-up study of an acute trial that enrolled aggressive children ages 6-12 years with a primary diagnosis of CD. To be enrolled into this study, subjects had to have successfully completed participation in the initial 8-week, open-label, outpatient quetiapine trial. Psychometric measures included the Rating of Aggression Against People and/or Property Scale (RAAPP), the Nisonger Child Behavior Rating Form (NCBRF), the Conners' Parent Rating Scale (CPRS-48), the Clinical Global Impressions Scale of Severity (CGI-S), and the Children's Global Assessment Scale.

RESULTS

Nine males with a mean age of 8.9 (SD = 1.2) years were treated. The median quetiapine dose at end of study was 150 mg/day (range 75-350). Mean psychometric scores did not change substantively from baseline. No patients experienced extrapyramidal side effects. Three subjects discontinued due to study nonadherence. No patients discontinued treatment due to an adverse event.

CONCLUSIONS

These preliminary data suggest that quetiapine might be a generally safe and effective maintenance treatment for aggressive children with CD who initially respond to an acute therapeutic trial of quetiapine. More research is needed to confirm or refute these initial findings.