Pharmacokinetic Evaluation of Intravenous Vitamin C: A Classic Pharmacokinetic Study.

PURPOSE: Intravenous vitamin C (IVC) is used in a variety of disorders with limited supporting pharmacokinetic data. Herein we report a pharmacokinetic study in healthy volunteers and cancer participants with IVC doses in the range of 1-100 g. METHODS: A pharmacokinetic study was conducted in 21 healthy volunteers and 12 oncology participants. Healthy participants received IVC infusions of 1-100 g; oncology participants received IVC infusions of 25-100 g. Serial blood and complete urine samples were collected pre-infusion and for 24 h post-infusion. Pharmacokinetic parameters were computed using noncompartmental methods. Adverse events were monitored during the study. RESULTS: In both cohorts, IVC exhibited first-order kinetics at doses up to 75 g. At 100 g, maximum concentration (Cmax) plateaued in both groups, whereas area under the concentration-time curve (AUC) only plateaued in the healthy group. IVC was primarily excreted through urine. No saturation of clearance was observed; however, the mean 24-h total IVC excretion in urine for all doses was lower in oncology participants (89% of dose) than in healthy participants at 100 g (99%). No significant adverse events were observed; thus, maximum tolerated dose (MTD) was not reached. CONCLUSION: IVC followed first-order pharmacokinetics up to 75 g and at up to 100 g had complete renal clearance in 24 h. IVC up to 100 g elicited no adverse effects or significant physiological/biochemical changes and appears to be safe. These data can be used to rectify existing misinformation and to guide future clinical trials. REGISTRATION: ClinicalTrials.gov identifier number NCT01833351.

A phase II clinical trial of neoadjuvant ketoconazole and docetaxel chemotherapy before radical prostatectomy in high risk patients.

PURPOSE: Patients with high risk prostate cancer (prostate specific antigen greater than 20 ng/ml, Gleason score greater than 7, or clinical stage T2b or greater) have been shown to have a 30% to 40% biochemical recurrence rate after definitive local therapy. Looking for improvement on these outcomes, we conducted a phase II clinical trial examining the combination of ketoconazole and docetaxel in the neoadjuvant setting before radical prostatectomy. MATERIALS AND METHODS: A total of 22 patients with clinically localized, high risk prostate cancer were enrolled in the study. For 12 weeks they were treated with neoadjuvant docetaxel and ketoconazole, with dosing based on phase I data. Patients were monitored for tolerance of therapy and dosing adjustments were made for significant toxicities. Radical prostatectomy with extended lymph node dissection was subsequently performed and patients were followed postoperatively for biochemical recurrence. RESULTS: At a median followup of 18 months 8 patients remained biochemically free of recurrence after surgery alone. An additional 6 patients received salvage therapy and had an undetectable prostate specific antigen. Of the 22 patients 16 experienced National Cancer Institute grade 3 or 4 toxicity at some point during the therapy. However, 16 patients completed all 4 cycles of chemotherapy. CONCLUSIONS: Neoadjuvant ketoconazole combined with docetaxel has appreciable but acceptable toxicity with 73% of the patients completing all 4 courses of therapy. Of those who underwent radical prostatectomy 36% remained continuously biochemically free of recurrence at a median followup of 18 months.

College and university compliance with a required meningococcal vaccination law.

OBJECTIVE: Maryland became the first state to pass a vaccination law requiring college and university students living on campus to obtain a meningococcal vaccination or to sign a waiver refusing vaccination because college students are at increased risk for disease. The authors sought to identify how Maryland colleges addressed the law and determine whether schools were in full compliance. PARTICIPANTS: The authors surveyed 32 college/university administrators via a self-administered questionnaire. METHODS: The authors calculated vaccination and waiver rates and assessed compliance with the law overall and with specific law components. RESULTS: Among 28 participating schools, annual vaccination rates and waiver rates among students during 2000-2004 ranged from 66%-76% and 12%-17%, respectively. Two (7%) schools were compliant with all components of the law. CONCLUSIONS: Mandatory vaccination laws do not ensure compliance at the college and university level. Mandatory reporting, increased education, and collaboration between colleges and universities and public health agencies are needed.

Pandemic influenza preparedness in Maryland: improving readiness through a tabletop exercise.

In February 1999, the Maryland Department of Health and Mental Hygiene initiated pandemic influenza planning for the state of Maryland. This process involved several major steps, including the development of the Maryland Pandemic Influenza Preparedness Plan, and culminated in a high-level tabletop exercise to test the plan in April 2004. During the tabletop exercise, participants were presented with nine different fictitious scripts encompassing a single scenario. They were asked to respond to the information presented in each script, discuss organization-specific questions posed by the exercise facilitator, and make decisions regarding action steps that their organization would take in response to the various issues raised. The exercise identified a number of important gaps that need to be addressed, including (1) additional surge capacity specific to a pandemic, (2) greater understanding of the realities and implications of pandemic influenza among elected officials and decision-makers, (3) coordination of pandemic influenza planning with the existing emergency response infrastructure coupled with additional training in incident command, (4) further steps to operationalize several aspects of the Maryland Pandemic Influenza Preparedness Plan, and (5) additional federal guidance.

Dopamine alleviation of diaphragm contractile dysfunction and reduction of deoxyribonucleic acid damage in rats.

BACKGROUND: Weaning difficulties from mechanical ventilation are associated with diaphragm fatigue and reduced respiratory muscle endurance capacity. Often the work of breathing is increased during the weaning process as a result of inspiratory resistance loading (IRL). IRL produces increased free radical formation that contributes to deoxyribonucleic acid (DNA) damage. The purpose of this study was to determine whether dopamine reduced nuclei DNA damage when the work of breathing was increased. We hypothesized that the administration of low-dose dopamine (2 microg/kg/min) during IRL decreases myonuclei DNA damage associated with free radical formation. METHODS: In this in vivo study, 30 male Sprague-Dawley rats were divided into three groups: (1) the sham group receiving no IRL or no intravenous fluids, (2) IRL with administration intravenous saline, and (3) IRL with intravenous low-dose dopamine (2 microg/kg/min). All rats from the same breed and similar colonies were purchased from one laboratory facility to ensure homogeneity. The animals were anesthetized and tracheotomized, and an ultrasonic sensor was attached to the right hemidiaphragm to measure diaphragm shortening. Diaphragm fatigue was produced by IRL. Dopamine (2 microg/kg/min) was infused intravenously before and during loading. The diaphragms were excised, and myonuclei DNA damage was measured using the fluorescent dyes ethidium bromide and acridine orange and comet analyses as indices of free radical injury. RESULTS: In rats receiving saline, diaphragm shortening decreased by 37% after 45 minutes of IRL (P = .002) compared with baseline. In contrast, rats infused with dopamine exhibited a 31% increase in diaphragm shortening after 45 minutes of IRL (P = .037). With the use of differential dye uptake, in the saline group 59% of the nuclei were apoptotic, and 18% were necrotic. However, in the dopamine group there was significantly less apoptotic nuclei (16%, P < .001) and necrotic nuclei (7%, P = .005). Myonuclei DNA damage, measured by comet analyses, was associated with tail length and tail olive moment, which were 37% and 60% greater, respectively, in the saline group than in the dopamine group (P < .05). CONCLUSION: These data support the hypothesis that low-dose dopamine during IRL reduced myonuclei DNA damage as measured by the fluorescent dyes and comet analysis. In addition, diaphragm fatigue was prevented by the administration of dopamine during IRL.