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result(s) for
"Drug clearance"
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Inhaled mannitol for non-cystic fibrosis bronchiectasis: a randomised, controlled trial
by
Dupont, Lieven J A
,
van Haren, Eric H J
,
Wu, Jian
in
Administration, Inhalation
,
Adolescent
,
Adult
2014
Bronchiectasis is characterised by excessive production of mucus and pulmonary exacerbations. Inhaled osmotic agents may enhance mucociliary clearance, but few long-term clinical trials have been conducted.
To determine the impact of inhaled mannitol on exacerbation rates in patients with non-cystic fibrosis (CF) bronchiectasis. Secondary endpoints included time to first exacerbation, duration of exacerbations, antibiotic use for exacerbations and quality of life (QOL) (St George's Respiratory Questionnaire, SGRQ).
Patients with non-CF bronchiectasis and a history of chronic excess production of sputum and ≥2 pulmonary exacerbations in the previous 12 months were randomised (1:1) to 52 weeks treatment with inhaled mannitol 400 mg or low-dose mannitol control twice a day. Patients were 18-85 years of age, baseline FEV1 ≥40% and ≤85% predicted and a baseline SGRQ score ≥30.
461 patients (233 in the mannitol and 228 in the control arm) were treated. Baseline demographics were similar in the two arms. The exacerbation rate was not significantly reduced on mannitol (rate ratio 0.92, p=0.31). However, time to first exacerbation was increased on mannitol (HR 0.78, p=0.022). SGRQ score was improved on mannitol compared with low-dose mannitol control (-2.4 units, p=0.046). Adverse events were similar between groups.
Mannitol 400 mg inhaled twice daily for 12 months in patients with clinically significant bronchiectasis did not significantly reduce exacerbation rates. There were statistically significant improvements in time to first exacerbation and QOL. Mannitol therapy was safe and well tolerated.
NCT00669331.
Journal Article
Mucus Clearance and Lung Function in Cystic Fibrosis with Hypertonic Saline
by
Bennett, William D
,
Donaldson, Scott H
,
Knowles, Michael R
in
Administration, Inhalation
,
Adolescent
,
Adult
2006
Inhalation of hypertonic saline has a modest beneficial effect on lung function and the frequency of exacerbations in patients with cystic fibrosis. In this article, the investigators provide in vivo and in vitro data suggesting that this therapeutic effect derives from sustained acceleration of mucus clearance.
The investigators provide in vivo and in vitro data suggesting that the therapeutic effect of inhaled hypertonic saline derives from sustained acceleration of mucus clearance.
Mucus clearance defends the lung against inhaled bacteria. The efficiency of mucus clearance depends on an adequate volume of airway surface liquid (i.e., hydration).
1
One hypothesis for the pathogenesis of lung disease in patients with cystic fibrosis is that a lack of regulation of sodium absorption and chloride secretion causes depletion of airway surface liquid, slows mucus clearance, and promotes the formation of adherent mucus plaques on airway surfaces. Mucus plaques and plugs obstruct airways and provide the nidus for infection.
2
,
3
On the basis of this hypothesis, therapies that increase the volume of airway surface liquid, and hence mucus . . .
Journal Article
Long-Term Inhaled Dry Powder Mannitol in Cystic Fibrosis: An International Randomized Study
by
Flume, Patrick A.
,
Geller, David E.
,
Hebestreit, Helge U.
in
Administration, Inhalation
,
Adolescent
,
Adult
2012
Abstract
Rationale
New treatment strategies are needed to improve airway clearance and reduce the morbidity and the time burden associated with cystic fibrosis (CF).
Objectives
To determine whether long-term treatment with inhaled mannitol, an osmotic agent, improves lung function and morbidity.
Methods
Double-blind, randomized, controlled trial of inhaled mannitol, 400 mg twice a day (n = 192, “treated” group) or 50 mg twice a day (n = 126, “control” group) for 26 weeks, followed by 26 weeks of open-label treatment.
Measurements and Main Results
The primary endpoint was absolute change in FEV1 from baseline in treated versus control groups, averaged over the study period. Secondary endpoints included other spirometric measurements, pulmonary exacerbations, and hospitalization. Clinical, microbiologic, and laboratory safety were assessed. The treated group had a mean improvement in FEV1 of 105 ml (8.2% above baseline). The treated group had a relative improvement in FEV1 of 3.75% (P = 0.029) versus the control group. Adverse events and sputum microbiology were similar in both treatment groups. Exacerbation rates were low, but there were fewer in the treated group (hazard ratio, 0.74; 95% confidence interval, 0.42–1.32; P = 0.31), although this was not statistically significant. In the 26-week open-label extension study, FEV1 was maintained in the original treated group, and improved in the original control group to the same degree.
Conclusions
Inhaled mannitol, 400 mg twice a day, resulted in improved lung function over 26 weeks, which was sustained after an additional 26 weeks of treatment. The safety profile was also acceptable, demonstrating the potential role for this chronic therapy for CF.
Clinical trial registered with www.clinicaltrials.gov (NCT 00630812).
Journal Article
Pharmacokinetics and dosage adjustment in patients with hepatic dysfunction
by
Verbeeck, Roger K
in
Bioavailability
,
Biological and medical sciences
,
Biomedical and Life Sciences
2008
The liver plays a central role in the pharmacokinetics of the majority of drugs. Liver dysfunction may not only reduce the blood/plasma clearance of drugs eliminated by hepatic metabolism or biliary excretion, it can also affect plasma protein binding, which in turn could influence the processes of distribution and elimination. Portal-systemic shunting, which is common in advanced liver cirrhosis, may substantially decrease the presystemic elimination (i.e., first-pass effect) of high extraction drugs following their oral administration, thus leading to a significant increase in the extent of absorption. Chronic liver diseases are associated with variable and non-uniform reductions in drug-metabolizing activities. For example, the activity of the various CYP450 enzymes seems to be differentially affected in patients with cirrhosis. Glucuronidation is often considered to be affected to a lesser extent than CYP450-mediated reactions in mild to moderate cirrhosis but can also be substantially impaired in patients with advanced cirrhosis. Patients with advanced cirrhosis often have impaired renal function and dose adjustment may, therefore, also be necessary for drugs eliminated by renal exctretion. In addition, patients with liver cirrhosis are more sensitive to the central adverse effects of opioid analgesics and the renal adverse effects of NSAIDs. In contrast, a decreased therapeutic effect has been noted in cirrhotic patients with β-adrenoceptor antagonists and certain diuretics. Unfortunately, there is no simple endogenous marker to predict hepatic function with respect to the elimination capacity of specific drugs. Several quantitative liver tests that measure the elimination of marker substrates such as galactose, sorbitol, antipyrine, caffeine, erythromycin, and midazolam, have been developed and evaluated, but no single test has gained widespread clinical use to adjust dosage regimens for drugs in patients with hepatic dysfunction. The semi-quantitative Child-Pugh score is frequently used to assess the severity of liver function impairment, but only offers the clinician rough guidance for dosage adjustment because it lacks the sensitivity to quantitate the specific ability of the liver to metabolize individual drugs. The recommendations of the Food and Drug Administration (FDA) and the European Medicines Evaluation Agency (EMEA) to study the effect of liver disease on the pharmacokinetics of drugs under development is clearly aimed at generating, if possible, specific dosage recommendations for patients with hepatic dysfunction. However, the limitations of the Child-Pugh score are acknowledged, and further research is needed to develop more sensitive liver function tests to guide drug dosage adjustment in patients with hepatic dysfunction.
Journal Article
Pharmacokinetics and dosage adjustment in patients with renal dysfunction
by
Musuamba, Flora T
,
Verbeeck, Roger K
in
Biological and medical sciences
,
Biomarkers - blood
,
Biomedical and Life Sciences
2009
Introduction Chronic kidney disease is a common, progressive illness that is becoming a global public health problem. In patients with kidney dysfunction, the renal excretion of parent drug and/or its metabolites will be impaired, leading to their excessive accumulation in the body. In addition, the plasma protein binding of drugs may be significantly reduced, which in turn could influence the pharmacokinetic processes of distribution and elimination. The activity of several drug-metabolizing enzymes and drug transporters has been shown to be impaired in chronic renal failure. In patients with end-stage renal disease, dialysis techniques such as hemodialysis and continuous ambulatory peritoneal dialysis may remove drugs from the body, necessitating dosage adjustment. Methods Inappropriate dosing in patients with renal dysfunction can cause toxicity or ineffective therapy. Therefore, the normal dosage regimen of a drug may have to be adjusted in a patient with renal dysfunction. Dosage adjustment is based on the remaining kidney function, most often estimated on the basis of the patient's glomerular filtration rate (GFR) estimated by the Cockroft-Gault formula. Net renal excretion of drug is a combination of three processes: glomerular filtration, tubular secretion and tubular reabsorption. Therefore, dosage adjustment based on GFR may not always be appropriate and a re-evaluation of markers of renal function may be required. Discussion According to EMEA and FDA guidelines, a pharmacokinetic study should be carried out during the development phase of a new drug that is likely to be used in patients with renal dysfunction and whose pharmacokinetics are likely to be significantly altered in these patients. This study should be carried out in carefully selected subjects with varying degrees of renal dysfunction. In addition to this two-stage pharmacokinetic approach, a population PK/PD study in patients participating in phase II/phase III clinical trials can also be used to assess the impact of renal dysfunction on the drug's pharmacokinetics and pharmacodynamics. Conclusion In conclusion, renal dysfunction affects more that just the renal handling of drugs and/or active drug metabolites. Even when the dosage adjustment recommended for patients with renal dysfunction are carefully followed, adverse drug reactions remain common.
Journal Article
Acute Effect of E-Cigarette Inhalation on Mucociliary Clearance in E-Cigarette Users
by
Zeman, Kirby L.
,
Clapp, Phillip W.
,
Ring, Brian
in
Administration, Inhalation
,
Adolescent
,
Adult
2024
Background:
Recent studies show e-cigarette (EC) users have increased rates of chronic bronchitic symptoms that may be associated with depressed mucociliary clearance (MCC). Little is known about the acute or chronic effects of EC inhalation on
in vivo
MCC.
Methods:
In vivo
MCC was measured in young adult vapers (
n
= 5 males, mean age = 21) after controlled inhalation of a radiolabeled (Tc99m sulfur colloid) aerosol. Whole-lung clearance of radiolabeled deposited particles was measured over a 90-minute period for baseline MCC and associated with controlled periodic vaping over the first 60 minutes of MCC measurements. The vaping challenge was administered from a fourth generation box mod EC containing unflavored e-liquid (65% propylene glycol/35% vegetable glycerin, 3 mg/mL freebase nicotine). The challenge was administered at the start of each 10-minute interval of MCC measurements and consisted of 1 puff every 30 seconds for 5 minutes (i.e., 10 puffs for each 10-minute period for a total of 60 puffs during the initial 60 minutes of MCC measurements).
Results:
Compared with baseline, peripheral lung average clearance (%) over the 90 minutes of MCC measures was enhanced, associated with EC challenge, 12 (±6) versus 24 (±6), respectively (
p
< 0.05 by Wilcoxon signed-rank test).
Conclusions:
Acute enhancement of
in vivo
MCC during EC challenge is contrary to recent studies showing nicotine-associated slowing of ciliary beat and mucus transport at higher nicotine levels than those used here. However, our findings are consistent with an acute increase in fluid volume and mucin secretion to the bronchial airway surface that is likely short lived. Research reported in this publication was supported by the National Institutes of Health R01HL139369 and registered with
ClinicalTrials.gov
(NCT03700892).
Journal Article
Lixisenatide Reduces Chylomicron Triacylglycerol by Increased Clearance
by
Hovorka, Roman
,
Russell-Jones, David
,
Fielding, Barbara
in
Acetaminophen
,
Analgesics
,
Blood glucose
2019
Abstract
Context
Glucagon-like peptide-1 (GLP-1) agonists control postprandial glucose and lipid excursion in type 2 diabetes; however, the mechanisms are unclear.
Objective
To determine the mechanisms of postprandial lipid and glucose control with lixisenatide (GLP-1 analog) in type 2 diabetes.
Design
Randomized, double-blind, cross-over study.
Setting
Centre for Diabetes, Endocrinology, and Research, Royal Surrey County Hospital, Guildford, United Kingdom.
Patients
Eight obese men with type 2 diabetes [age, 57.3 ± 1.9 years; body mass index, 30.3 ± 1.0 kg/m2; glycosylated hemoglobin, 66.5 ± 2.6 mmol/mol (8.2% ± 0.3%)].
Interventions
Two metabolic studies, 4 weeks after lixisenatide or placebo, with cross-over and repetition of studies.
Main Outcome Measures
Study one: very-low-density lipoprotein (VLDL) and chylomicron (CM) triacylglycerol (TAG) kinetics were measured with an IV bolus of [2H5]glycerol in a 12-hour study, with hourly feeding. Oral [13C]triolein, in a single meal, labeled enterally derived TAG. Study two: glucose kinetics were measured with [U-13C]glucose in a mixed-meal (plus acetaminophen to measure gastric emptying) and variable IV [6,6-2H2]glucose infusion.
Results
Study one: CM-TAG (but not VLDL-TAG) pool-size was lower with lixisenatide (P = 0.046). Lixisenatide reduced CM [13C]oleate area under the curve (AUC)60–480min concentration (P = 0.048) and increased CM-TAG clearance, with no effect on CM-TAG production rate. Study two: postprandial glucose and insulin AUC0–240min were reduced with lixisenatide (P = 0.0051; P < 0.05). Total glucose production (P = 0.015), rate of glucose appearance from the meal (P = 0.0098), and acetaminophen AUC0–360min (P = 0.006) were lower with lixisenatide than with placebo.
Conclusions
Lixisenatide reduced [13C]oleate concentrations, derived from a single meal in CM-TAG and glucose rate of appearance from the meal through delayed gastric emptying. However, day-long CM production, measured with repeated meal feeding, was not reduced by lixisenatide and decreased CM-TAG concentration resulted from increased CM-TAG clearance.
Using stable isotopes, lixisenatide acutely slowed gastric emptying, lowering postprandial TAG levels. A more prolonged effect of reduced chylomicron TAG was from increased clearance.
Journal Article
Caspofungin Population Pharmacokinetics in Critically Ill Patients Undergoing Continuous Veno-Venous Haemofiltration or Haemodiafiltration
by
Muller, Laurent
,
Lipman, Jeffrey
,
Lefrant, Jean-Yves
in
Aged
,
Antifungal agents
,
Antifungal Agents - pharmacokinetics
2017
Background and Objective
Sepsis and continuous renal replacement therapy (CRRT) can both significantly affect antifungal pharmacokinetics. This study aimed to describe the pharmacokinetics of caspofungin in critically ill patients during different CRRT modes.
Methods
Patients receiving caspofungin and undergoing continuous veno-venous haemofiltration (CVVH) or haemodiafiltration (CVVHDF) were eligible to take part in the study. Blood samples were collected at seven sampling times during a dosing interval. Demographics and clinical data were recorded. Population pharmacokinetic analysis and Monte-Carlo simulation were undertaken using Pmetrics.
Results
Twelve pharmacokinetic profiles from nine patients were analysed. The caspofungin CRRT clearance (CL) was 0.048 ± 0.12 L/h for CVVH and 0.042 ± 0.042 L/h for CVVHDF. A two-compartment linear model best described the data. Patient weight was the only covariate affecting drug CL and central volume. The mean (standard deviation) parameter estimates were 0.64 ± 0.12 L/h for CL, 9.35 ± 3.56 L for central volume, 0.25 ± 0.19 per h for the rate constant for drug distribution from central to peripheral compartments and 0.19 ± 0.10 per h from peripheral to central compartments. Based on simulation results, a caspofungin 100 mg loading dose followed by a 50 mg maintenance dose for patients with a total body weight of ≤80 kg best achieved the pharmacokinetic/PD targets whilst a 70 mg maintenance dose was required for patients with a weight of >80 kg.
Conclusion
No caspofungin dosing adjustment is necessary for patients undergoing either form of CRRT. However, higher than recommended loading doses of caspofungin are required to achieve pharmacokinetic/pharmacodynamic targets in critically ill patients.
Registration: ClinicalTrials.gov Identifier NCT01403220
Journal Article
Impact of isotonic and hypertonic saline solutions on mucociliary activity in various nasal pathologies: clinical study
by
Kizil, Y
,
Oktemer, T Kocak
,
Ileri, F
in
Adult
,
Biological and medical sciences
,
Case-Control Studies
2009
To investigate the impact of nasal irrigation with isotonic or hypertonic sodium chloride solution on mucociliary clearance time in patients with allergic rhinitis, acute sinusitis and chronic sinusitis.
Mucociliary clearance time was measured using the saccharine clearance test on 132 adults before and after 10 days' application of intranasal isotonic or hypertonic saline. Patient numbers were as follows: controls, 45; allergic rhinitis, 21; acute sinusitis, 24; and chronic sinusitis, 42. The results before and after irrigation were compared using the Wilcoxon t-test.
Before application of saline solutions, mucociliary clearance times in the three patient treatment groups were found to be significantly delayed, compared with the control group. Irrigation with hypertonic saline restored impaired mucociliary clearance in chronic sinusitis patients (p < 0.05), while isotonic saline improved mucociliary clearance times significantly in allergic rhinitis and acute sinusitis patients (p < 0.05).
Nasal irrigation with isotonic or hypertonic saline can improve mucociliary clearance time in various nasal pathologies. However, these solutions should be selectively prescribed rather than used based on anecdotal evidence. Further studies should be conducted to develop a protocol for standardised use of saline solution irrigation in various nasal pathologies.
Journal Article
Pharmacokinetics and Pharmacodynamics of the Direct Oral Thrombin Inhibitor Dabigatran in Healthy Elderly Subjects
by
Rathgen, Karin
,
Fuhr, Reinhold
,
Stangier, Joachim
in
2-Pyridinylmethylsulfinylbenzimidazoles - administration & dosage
,
2-Pyridinylmethylsulfinylbenzimidazoles - pharmacology
,
Administration, Oral
2008
Objectives
To investigate the pharmacokinetic and pharmacodynamic profile of dabigatran in healthy elderly subjects; to assess the intra- and interindividual variability of dabigatran pharmacokinetics in order to assess possible gender differences; and to assess the effect of pantoprazole coadministration on the bioavailability of dabigatran.
Study design and setting
Open-label, parallel-group, single-centre study, consisting of a baseline screening visit, 7-day treatment period and post-study examination visit.
Subjects and intervention
36 healthy elderly subjects (aged ≥65 years) with a body mass index of 18.5–29.9 kg/m
2
. Subjects were randomized to receive dabigatran etexilate either with or without coadministration of pantoprazole. Dabigatran etexilate was administered as capsules at 150 mg twice daily over 6 days and once on the morning of day 7. Pantoprazole was administered at 40 mg twice daily, starting 2 days prior to dabigatran etexilate administration and ending on the morning of day 7.
Main outcome measures
The primary pharmacokinetic measurements included the area under the plasma concentration-time curve at steady state (AUC
ss
), maximum (Cmax,ss) and minimum (Cmin,ss) plasma concentrations at steady state, terminal half-life (t½), time to reach Cmax,ss and renal clearance of dabigatran. The secondary pharmacokinetic parameters included the mean residence time, total oral clearance and volume of distribution. The pharmacodynamic parameters measured were the blood coagulation parameters ecarin clotting time (ECT) and activated partial thromboplastin time (aPTT).
Results
With twice-daily administration of dabigatran etexilate, plasma concentrations of dabigatran reached steady state within 2–3 days, which is consistent with a t½ of 12–14 hours. The mean (SD) peak plasma concentrations on day 4 of treatment in male and female elderly subjects were 256 ng/mL (21.8) and 255 ng/mL (84.0), respectively. The peak plasma concentrations were reached after a median of 3 hours (range 2.0–4.0 hours). Coadministration with pantoprazole decreased the average bioavailability of dabigatran (the AUCss) by 24% (day 4; 90% CI 7.4, 37.8) and 20% (day 7; 90% CI 5.2, 33.3). Intra- and interindividual pharmacokinetic variability in the overall population was low (<30% coefficient of variation), indicating that dabigatran has a predictable pharmacokinetic profile. Prolongation of the ECT and aPTT correlated with, and paralleled, the plasma concentration-time profile of dabigatran, which demonstrates a rapid onset of action without a time delay, and also illustrates the direct mode of action of the drug on thrombin in plasma. The ECT increased in direct proportion to the plasma concentration, and the aPTT displayed a linear relationship with the square root of the plasma concentration. The mean AUCss was 3–19% higher in female subjects than in male subjects, which was likely due to gender differences in creatinine clearance. The safety profile of dabigatran was good, with and without pantoprazole coadministration.
Conclusions
Dabigatran demonstrated reproducible and predictable pharmacokinetic and pharmacodynamic characteristics, together with a good safety profile, when administered to healthy elderly subjects. Minor gender differences were not considered clinically relevant. The effects of pantoprazole coadministration on the bioavailability of dabigatran were considered acceptable, and dose adjustment is not considered necessary.
Journal Article