scholarly journals N-Acetyltransferase Genotypes and the Pharmacokinetics and Tolerability ofpara-Aminosalicylic Acid in Patients with Drug-Resistant Pulmonary Tuberculosis

2015 ◽  
Vol 59 (7) ◽  
pp. 4129-4138 ◽  
Author(s):  
Sherwin K. B. Sy ◽  
Lizanne de Kock ◽  
Andreas H. Diacon ◽  
Cedric J. Werely ◽  
Huiming Xia ◽  
...  
Keyword(s):  
Mass Function ◽  
Drug Clearance ◽  
Enzyme Analysis ◽  
Restriction Enzyme Analysis ◽  
Probability Mass Function ◽  
Aminosalicylic Acid ◽  
Open Label ◽  
Once Daily ◽  
In Series ◽  
Disposition Model

ABSTRACTThe aim of this study was to examine the relationships betweenN-acetyltransferase genotypes, pharmacokinetics, and tolerability of granular slow-releasepara-aminosalicylic acid (GSR-PAS) in tuberculosis patients. The study was a randomized, two-period, open-label, crossover design wherein each patient received 4 g GSR-PAS twice daily or 8 g once daily alternately. The PAS concentration-time profiles were modeled by a one-compartment disposition model with three transit compartments in series to describe its absorption. Patients'NAT1andNAT2genotypes were determined by sequencing and restriction enzyme analysis, respectively. The number of daily vomits was modeled by a Poisson probability mass function. Comparisons of other tolerability measures by regimens, gender, and genotypes were evaluated by a linear mixed-effects model. The covariate effects associated with efavirenz, gender, andNAT1*3,NAT1*14, andNAT2*5alleles corresponded to 25, 37, −17, −48, and −27% changes, respectively, in oral clearance of PAS. TheNAT1*10allele did not influence drug clearance. The time above the MIC of 1 mg/liter was significantly different between the two regimens but not influenced by theNAT1orNAT2genotypes. The occurrence and intensity of intolerance differed little between regimens. Four grams of GSR-PAS twice daily but not 8 g once daily ensured concentrations exceeding the MIC (1 mg/liter) throughout the dosing interval; PAS intolerance was not related to maximum PAS concentrations over the doses studied and was not more frequent after once-daily dosing. We confirm that the slow phenotype conferred by theNAT1*14andNAT1*3alleles resulted in higher PAS exposure but found no evidence of increased activity of theNAT1*10allele.

scholarly journals Pharmacokinetics of Second-Line Antituberculosis Drugs after Multiple Administrations in Healthy Volunteers

2015 ◽  
Vol 59 (8) ◽  
pp. 4429-4435 ◽  
Author(s):  
Sang-In Park ◽  
Jaeseong Oh ◽  
Kyungho Jang ◽  
Jangsoo Yoon ◽  
Seol Ju Moon ◽  
...  
Keyword(s):  
Plasma Concentration ◽  
Therapeutic Drug ◽  
Maximum Plasma ◽  
Second Line ◽  
Aminosalicylic Acid ◽  
Open Label ◽  
Multiple Dosing ◽  
Time Curve ◽  
Once Daily ◽  
Antituberculosis Drugs

ABSTRACTTherapeutic drug monitoring (TDM) of second-line antituberculosis drugs would allow for optimal individualized dosage adjustments and improve drug safety and therapeutic outcomes. To evaluate the pharmacokinetic (PK) characteristics of clinically relevant, multidrug treatment regimens and to improve the feasibility of TDM, we conducted an open-label, multiple-dosing study with 16 healthy subjects who were divided into two groups. Cycloserine (250 mg),p-aminosalicylic acid (PAS) (5.28 g), and prothionamide (250 mg) twice daily and pyrazinamide (1,500 mg) once daily were administered to both groups. Additionally, levofloxacin (750 mg) and streptomycin (1 g) once daily were administered to group 1 and moxifloxacin (400 mg) and kanamycin (1 g) once daily were administered to group 2. Blood samples for PK analysis were collected up to 24 h following the 5 days of drug administration. The PK parameters, including the maximum plasma concentration (Cmax) and the area under the plasma concentration-time curve during a dosing interval at steady state (AUCτ), were evaluated. The correlations between the PK parameters and the concentrations at each time point were analyzed. The meanCmaxand AUCτ, respectively, for each drug were as follows: cycloserine, 24.9 mg/liter and 242.3 mg · h/liter; PAS, 65.9 mg/liter and 326.5 mg · h/liter; prothionamide, 5.3 mg/liter and 22.1 mg · h/liter; levofloxacin, 6.6 mg/liter and 64.4 mg · h/liter; moxifloxacin, 4.7 mg/liter and 54.2 mg · h/liter; streptomycin, 42.0 mg/liter and 196.7 mg · h/liter; kanamycin, 34.5 mg/liter and 153.5 mg · h/liter. The results indicated that sampling at 1, 2.5, and 6 h postdosing is needed for TDM when all seven drugs are administered concomitantly. This study indicates that PK characteristics must be considered when prescribing optimal treatments for patients. (This study has been registered at ClinicalTrials.gov under registration no. NCT02128308.)

scholarly journals Pharmacokinetics and pharmacodynamics of ampreloxetine, a novel, selective norepinephrine reuptake inhibitor, in symptomatic neurogenic orthostatic hypotension

2021 ◽  
Author(s):  
Arthur Lo ◽  
Lucy Norcliffe-Kaufmann ◽  
Ross Vickery ◽  
David Bourdet ◽  
Jitendra Kanodia
Keyword(s):  
Orthostatic Hypotension ◽  
Sympathetic Neurons ◽  
Oral Treatment ◽  
Plasma Concentrations ◽  
Treatment Phase ◽  
Target Population ◽  
Neurogenic Orthostatic Hypotension ◽  
Open Label ◽  
Once Daily ◽  
Norepinephrine Reuptake

Abstract Purpose Ampreloxetine is a novel, selective, long-acting norepinephrine reuptake (NET) inhibitor being investigated as a once-daily oral treatment for symptomatic neurogenic orthostatic hypotension (nOH) in patients with autonomic synucleinopathies. The purpose of this study was to characterize the pharmacokinetic and pharmacodynamic profiles of ampreloxetine in this target population. Methods Patients with nOH were enrolled in a multicenter, phase II clinical trial of ampreloxetine (NCT02705755). They received escalating doses over 5 days in the clinical research unit, followed by 20 weeks of open-label treatment and then a 4-week withdrawal. As neurochemical biomarkers of NET inhibition, we assayed plasma concentrations of norepinephrine (NE) and its main intraneuronal metabolite 3,4-dihydroxyphenylglycol (DHPG) pre- and post-ampreloxetine. Results Thirty-four patients with nOH were enrolled. Plasma ampreloxetine concentrations increased with repeated escalating doses, with peak concentrations observed 6–9 h post-drug administration. The median ampreloxetine dose in the 20-week treatment phase was 10 mg once daily. Plasma ampreloxetine concentrations reached steady state by 2 weeks, with stable plasma levels over 24 h. No influence of age or renal function on ampreloxetine plasma concentrations was observed. On treatment, compared to baseline, plasma NE significantly increased by 71% (p < 0.005), plasma DHPG significantly declined by 22% (p < 0.05), and the NE:DHPG ratio significantly increased (p < 0.001). Conclusions Persistent elevation of plasma NE levels accompanied by reduced DHPG levels after ampreloxetine suggests reduced neuronal reuptake and metabolism of NE in postganglionic efferent sympathetic neurons. The findings are consistent with long-lasting NET inhibition, which may increase vasoconstrictor tone, supporting once-daily ampreloxetine dosing in patients with nOH.

scholarly journals A Prospective Open-Label Multicentre Trial on the Use of 1 G, Once Daily Ceftriaxone in Lower Respiratory Tract Infections

1994 ◽  
Vol 5 (suppl c) ◽  
pp. 3C-8C ◽  
Author(s):  
Donald E Low ◽  
Lionel A Mandell
Keyword(s):  
Respiratory Tract ◽  
Treatment Failure ◽  
Lower Respiratory Tract ◽  
Study Drug ◽  
Open Label ◽  
In Vitro Susceptibility ◽  
Once Daily ◽  
Minimal Inhibitory Concentrations ◽  
Tract Infections

This prospective. single open-label sludy was conducted in 14 Canadian centres to assess lhe efncacy of I g, once a day intravenous ceftriaxone treatment administered for a minimum of three days in patients with lower respiratory tract infection. There were 137 patients enrolled. Age varied between 19 and 95 years (mean 68 years). Mosl patients (91 %) were diagnosed with community acquired pneumonia without bacteremia. Most of the cases (82%) were defined as modcralc or severe. Patients received ceftriaxone treatment for an average or five days. Macrolidcs or metronidazole were administered concomitantly wilh ceftriaxone in 34 patienls (25%). After a minimum of three days of ceftriaxone treatment. 59 palicnls (43%) were switched to oral antibiotics. Favourable treatment outcome was found in 92.9% and treatment failure (including relapse of infection) in 7.1 % o lpalicnls. Evaluable patients accounted for 91 % of patients enrolled in the study. Clinical cure and clinical improvement were achieved in 64.6 and 28.3% of the evaluable patients. respectively. Relapse of infection occurred in two patients (1.8%). and treatment failure was recorded in six cases (5.3%). Twelve patients (8.8%) died clue to reasons unrelated to the sludy treatment. Three adverse event (hives, diarrhea and phlebitis at the injection site) were possibly related to the study drug. A cross-Canada in vitro susceptibility surveillance study of bacterial pathogens. frequently the cause of pneumonia. found ceftriaxone to have minimal inhibitory concentrations in 90% of isolates that would support such a dosing regimen. with the exception of Enterobacter species. These rcsults support the use of 1 g, once daily ceftriaxone for the empirical treatment of pneumonia in those patients requiring hospitalization.

scholarly journals Detecting Different Road Infrastructural Elements Based on the Stochastic Characterization of Speed Patterns

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Mario Muñoz-Organero ◽  
Ramona Ruiz-Blázquez
Keyword(s):  
Total Variation ◽  
Traffic Congestion ◽  
Automatic Detection ◽  
Mass Function ◽  
Total Variation Distance ◽  
Statistical Moments ◽  
Probability Mass Function ◽  
Traffic Lights ◽  
Traffic Conditions ◽  
Variation Distance

The automatic detection of road related information using data from sensors while driving has many potential applications such as traffic congestion detection or automatic routable map generation. This paper focuses on the automatic detection of road elements based on GPS data from on-vehicle systems. A new algorithm is developed that uses the total variation distance instead of the statistical moments to improve the classification accuracy. The algorithm is validated for detecting traffic lights, roundabouts, and street-crossings in a real scenario and the obtained accuracy (0.75) improves the best results using previous approaches based on statistical moments based features (0.71). Each road element to be detected is characterized as a vector of speeds measured when a driver goes through it. We first eliminate the speed samples in congested traffic conditions which are not comparable with clear traffic conditions and would contaminate the dataset. Then, we calculate the probability mass function for the speed (in 1 m/s intervals) at each point. The total variation distance is then used to find the similarity among different points of interest (which can contain a similar road element or a different one). Finally, a k-NN approach is used for assigning a class to each unlabelled element.

Short- and Long-Term Cardiovascular Effects of Mixed Amphetamine Salts Extended-Release in Adolescents With ADHD

CNS Spectrums ◽  
2005 ◽  
Vol 10 (S15) ◽  
pp. 22-30 ◽  
Author(s):  
Timothy E. Wilens ◽  
Thomas J. Spencer ◽  
Joseph Biederman
Keyword(s):  
Extended Release ◽  
Cardiovascular Effects ◽  
Dose Titration ◽  
Open Label ◽  
Double Blind ◽  
Once Daily ◽  
Open Label Extension ◽  
Short And Long Term ◽  
Clinically Significant

AbstractObjectiveAssess cardiovascular effects of once-daily mixed amphetamine salts extended release (MAS XR) in adolescents (13–17 years of age) with attention-deficit/hyperactivity disorder (ADHD).MethodsBlood pressure (BP), pulse, and electrocardiograms were assessed in 327 healthy subjects during a 4-week, randomized, double-blind, placebo-controlled, forced dose-titration study. Placebo (n=69) or once-daily MAS XR(10, 20, 30, or 40 mg) was administered to subjects ≤75 kg (n=233); 50- and 60-mg MAS XR was administered to subjects >75 kg (n=25). One hundred thirty-eight subjects participated in a 6-month, open-label extension study.FindingsChanges in BP and QTcB (Bazett's formula) intervals at 4 weeks with MAS XR were not significantly different from the placebo group. Pulse increased by 5.0 and 8.5 bpm after 3 weeks with MAS XR 20 and 50 mg/day, respectively (P≤.002). After 6 months of open-label MAS XR treatment, mean increases in systolic BP (1.7 mm Hg; P=.0252) and pulse (4.4 bpm; P<.0001) were statistically, but not clinically, significant diastolic BP was not significantly changed (0.6 mm Hg) A decrease in QTcB interval (-4.6±19.9 msec) was statistically (P=.009), but not clinically, significant. There were no serious cardiovascular adverse events.ConclusionCardiovascular effects of short- and long-term MAS XR treatment (≤60 mg/day) were minimal in otherwise healthy adolescents with ADHD.

ABPM Comparison of the Anti-Hypertensive Profiles of Telmisartan and Enalapril in Patients with Mild-to-Moderate Essential Hypertension

2002 ◽  
Vol 30 (6) ◽  
pp. 543-552 ◽  
Author(s):  
J Amerena ◽  
S Pappas ◽  
J-P Ouellet ◽  
L Williams ◽  
D O'Shaughnessy
Keyword(s):  
Blood Pressure ◽  
Essential Hypertension ◽  
Blood Pressure Monitoring ◽  
Study Drug ◽  
Pressure Control ◽  
Moderate Essential Hypertension ◽  
Open Label ◽  
Night Time ◽  
Once Daily

In this multicentre, prospective, randomized, open-label, blinded-endpoint (PROBE) study, the efficacy of 12 weeks' treatment with once-daily telmisartan 40–80 mg and enalapril 10–20 mg was evaluated using ambulatory blood pressure monitoring (ABPM) in 522 patients with mild-to-moderate essential hypertension. Patients were titrated to the higher dose of study drug at week 6 if mean seated diastolic blood pressure (DBP) was ≥ 90 mmHg. The primary endpoint was the change from baseline in ambulatory DBP in the last 6 h of the 24-h dosing interval after 12 weeks' treatment. Telmisartan and enalapril produced similar reductions from baseline in DBP and systolic blood pressure (SBP) over all ABPM periods evaluated (last 6 h, 24-h, daytime and night-time). Telmisartan produced a significantly greater reduction in mean seated trough DBP, measured unblinded with an automated ABPM device in the clinic, amounting to a difference of −2.02 mmHg ( P < 0.01). A significantly greater proportion of patients achieved a seated diastolic response with telmisartan than enalapril (59% versus 50%; P < 0.05), also measured with the same ABPM device. Both treatments were well tolerated. Compared with telmisartan, enalapril was associated with a higher incidence of cough (8.9% versus 0.8%) and hypotension (3.9% versus 1.1%). Therefore, telmisartan may provide better long-term compliance and, consequently, better blood pressure control than enalapril.

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