Pharmacokinetic and Pharmacodynamic Interaction Between Allopurinol and Probenecid in Patients with Gout

2011 ◽  
Vol 38 (5) ◽  
pp. 904-910 ◽  
Author(s):  
SOPHIE L. STOCKER ◽  
GARRY G. GRAHAM ◽  
ANDREW J. McLACHLAN ◽  
KENNETH M. WILLIAMS ◽  
RICHARD O. DAY
Keyword(s):  
Clinical Trials ◽  
Active Metabolite ◽  
Plasma Concentrations ◽  
Open Label ◽  
Pharmacodynamic Interaction ◽  
Daily Dose ◽  
Renal Clearances ◽  
Blood And Urine Samples ◽  
Plasma Urate ◽  
Clinical Trials Registry

Objective.To investigate the pharmacokinetic and pharmacodynamic interaction between probenecid and oxypurinol (the active metabolite of allopurinol) in patients with gout.Methods.This was an open-label observational clinical study. Blood and urine samples were collected to measure oxypurinol and urate concentrations. We examined the effects of adding probenecid to allopurinol therapy upon plasma concentrations and renal clearances of urate and oxypurinol.Results.Twenty patients taking allopurinol 100–400 mg daily completed the study. Maximum coadministered doses of probenecid were 250 mg/day (n = 1), 500 mg/day (n = 19), 1000 mg/day (n = 7), 1500 mg/day (n = 3), and 2000 mg/day (n = 1). All doses except the 250 mg daily dose were divided and dosing was twice daily. Estimated creatinine clearances ranged from 28 to 113 ml/min. Addition of probenecid 500 mg/day to allopurinol therapy decreased plasma urate concentrations by 25%, from mean 0.37 mmol/l (95% CI 0.33–0.41) to mean 0.28 mmol/l (95% CI 0.24–0.32) (p < 0.001); and increased renal urate clearance by 62%, from mean 6.0 ml/min (95% CI 4.5–7.5) to mean 9.6 ml/min (95% CI 6.9–12.3) (p < 0.001). Average steady-state plasma oxypurinol concentrations decreased by 26%, from mean 11.1 mg/l (95% CI 5.0–17.3) to mean 8.2 mg/l (95% CI 4.0–12.4) (p < 0.001); and renal oxypurinol clearance increased by 24%, from mean 12.7 ml/min (95% CI 9.6–15.8) to mean 16.1 ml/min (95% CI 12.0–20.2) (p < 0.05). The additional hypouricemic effect of probenecid 500 mg/day appeared to be lower in patients with renal impairment.Conclusion.Coadministration of allopurinol with probenecid had a significantly greater hypouricemic effect than allopurinol alone despite an associated reduction of plasma oxypurinol concentrations. Australian Clinical Trials Registry ACTRN012606000276550.

scholarly journals THE INFLUENCE OF PAROXETINE ON THE PHARMACOKINETICS OF ATOMOXETINE AND ITS MAIN METABOLITE

2015 ◽  
Vol 88 (4) ◽  
pp. 513-520 ◽  
Author(s):  
Ioana Todor ◽  
Adina Popa ◽  
Maria Neag ◽  
Dana Muntean ◽  
Corina Bocsan ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Active Metabolite ◽  
Multiple Dose ◽  
Plasma Concentrations ◽  
Pharmacokinetic Parameters ◽  
Extensive Metabolizers ◽  
Open Label ◽  
Main Metabolite ◽  
Daily Dose ◽  
Metabolite Pharmacokinetics

Background and aims. To evaluate the effects of paroxetine on the pharmacokinetics of atomoxetine and its main metabolite, 4-hydroxyatomoxetine-O-glucuronide, after coadministration of atomoxetine and paroxetine in healthy volunteers.Methods. 22 healthy volunteers, extensive metabolizers, took part in this open-label, non-randomized, clinical trial. The study consisted of two periods: Reference, when a single oral dose of 25 mg atomoxetine was administrated to each subject and Test, when 25 mg atomoxetine  and 20 mg paroxetine were coadministered. Between the two periods, the volunteers received an oral daily dose of 20-40 mg paroxetine, for 6 days. Atomoxetine and 4-hydroxyatomoxetine-O-glucuronide plasma concentrations were determined within the first 48 hours following drug administration. The pharmacokinetic parameters of both compounds were assessed using a non-compartmental method and the analysis of variance aimed at identifying any statistical significant differences between the pharmacokinetic parameters of atomoxetine and its main metabolite, corresponding to each study period.Results. Paroxetine modified the pharmacokinetic parameters of atomoxetine. Cmax increased from 221.26±94.93 to 372.53±128.28 ng/mL, while AUC0-t and AUC0-∞ also increased from 1151.19±686.52 to 6452.37±3388.76 ng*h/mL, and from 1229.15±751.04 to 7111.74±4195.17 ng*h/mL respectively. The main metabolite pharmacokinetics was also influenced by paroxetine intake, namely Cmax, AUC0-t and AUC0-∞ decreased from 688.76±270.27 to 131.01±100.43 ng*h/mL, and from 4810.93±845.06 to 2606.04±923.88 and from 4928.55±853.25 to 3029.82 ±941.84 respectively.Conclusions. Multiple-dose paroxetine intake significantly influenced atomoxetine and its active metabolite pharmacokinetics, causing a 5.8-fold increased exposure to atomoxetine and 1.6-fold reduced exposure to 4-hydroxyatomoxetine-O-glucuronide.

scholarly journals Artesunate Suppositories versus Intramuscular Artemether for Treatment of Severe Malaria in Children in Papua New Guinea

2006 ◽  
Vol 50 (3) ◽  
pp. 968-974 ◽  
Author(s):  
Harin A. Karunajeewa ◽  
John Reeder ◽  
Kerry Lorry ◽  
Elizah Dabod ◽  
Juliana Hamzah ◽  
...  
Keyword(s):  
Severe Malaria ◽  
Papua New Guinea ◽  
Active Metabolite ◽  
Treated Patient ◽  
Plasma Concentrations ◽  
New Guinea ◽  
Parasite Clearance ◽  
Parenteral Therapy ◽  
Open Label ◽  
Initial Plasma

ABSTRACT Drug treatment of severe malaria must be rapidly effective. Suppositories may be valuable for childhood malaria when circumstances prevent oral or parenteral therapy. We compared artesunate suppositories (n = 41; 8 to 16 mg/kg of body weight at 0 and 12 h and then daily) with intramuscular (i.m.) artemether (n = 38; 3.2 mg/kg at 0 h and then 1.6 mg/kg daily) in an open-label, randomized trial with children with severe Plasmodium falciparum malaria in Papua New Guinea (PNG). Parasite density and temperature were measured every 6 h for ≥72 h. Primary endpoints included times to 50% and 90% parasite clearance (PCT50 and PCT90) and the time to per os status. In a subset of 29 patients, plasma levels of artemether, artesunate, and their common active metabolite dihydroartemisinin were measured during the first 12 h. One suppository-treated patient with multiple complications died within 2 h of admission, but the remaining 78 recovered uneventfully. Compared to the artemether-treated children, those receiving artesunate suppositories had a significantly earlier mean PCT50 (9.1 versus 13.8 h; P = 0.008) and PCT90 (15.6 versus 20.4 h; P = 0.011). Mean time to per os status was similar for each group. Plasma concentrations of primary drug plus active metabolite were significantly higher in the artesunate suppository group at 2 h postdose. The earlier initial fall in parasitemia with artesunate is clinically advantageous and mirrors higher initial plasma concentrations of active drug/metabolite. In severely ill children with malaria in PNG, artesunate suppositories were at least as effective as i.m. artemether and may, therefore, be useful in settings where parenteral therapy cannot be given.

scholarly journals Evaluation of the efficacy and safety of icatibant and C1 esterase/kallikrein inhibitor in severe COVID-19: study protocol for a three-armed randomized controlled trial

Trials ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Eli Mansour ◽  
Flávia F. Bueno ◽  
José C. de Lima-Júnior ◽  
Andre Palma ◽  
Milena Monfort-Pires ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Standard Care ◽  
Controlled Trial ◽  
Supplemental Oxygen ◽  
Common Side Effect ◽  
Open Label ◽  
Angiotensin Converting Enzyme 2 ◽  
Lung Structure ◽  
Parallel Group ◽  
Clinical Trials Registry

Abstract Background SARS-CoV-2, the virus that causes COVID-19, enters the cells through a mechanism dependent on its binding to angiotensin-converting enzyme 2 (ACE2), a protein highly expressed in the lungs. The putative viral-induced inhibition of ACE2 could result in the defective degradation of bradykinin, a potent inflammatory substance. We hypothesize that increased bradykinin in the lungs is an important mechanism driving the development of pneumonia and respiratory failure in COVID-19. Methods This is a phase II, single-center, three-armed parallel-group, open-label, active control superiority randomized clinical trial. One hundred eighty eligible patients will be randomly assigned in a 1:1:1 ratio to receive either the inhibitor of C1e/kallikrein 20 U/kg intravenously on day 1 and day 4 plus standard care; or icatibant 30 mg subcutaneously, three doses/day for 4 days plus standard care; or standard care alone, as recommended in the clinical trials published to date, which includes supplemental oxygen, non-invasive and invasive ventilation, antibiotic agents, anti-inflammatory agents, prophylactic antithrombotic therapy, vasopressor support, and renal replacement therapy. Discussion Accumulation of bradykinin in the lungs is a common side effect of ACE inhibitors leading to cough. In animal models, the inactivation of ACE2 leads to severe acute pneumonitis in response to lipopolysaccharide (LPS), and the inhibition of bradykinin almost completely restores the lung structure. We believe that inhibition of bradykinin in severe COVID-19 patients could reduce the lung inflammatory response, impacting positively on the severity of disease and mortality rates. Trial registration Brazilian Clinical Trials Registry Universal Trial Number (UTN) U1111-1250-1843. Registered on May/5/2020.

scholarly journals Osteoporosis-Related Randomized Clinical Trials With Middle-Aged and Older Adults Registered on the International Clinical Trials Registry Platform

2021 ◽  
Vol 12 ◽  
Author(s):  
Fenghua Lai ◽  
Ling Pei ◽  
Xinwen Chen ◽  
Jin Li
Keyword(s):  
Older Adults ◽  
Clinical Trials ◽  
Randomized Clinical Trials ◽  
Publication Rate ◽  
Middle Aged ◽  
Open Label ◽  
Or Education ◽  
Clinical Trial Designs ◽  
Clinical Trials Registry ◽  
Older Populations

BackgroundA better understanding of the current features of osteoporosis-related randomized clinical trials (RCTs) is important for improving clinical trial designs and promoting the translatability of results into benefits for patients. However, there is a lack of thorough evaluation of osteoporosis-related RCTs in middle-aged and older populations. Therefore, this study aimed to investigate the characteristics of registered RCTs on osteoporosis among middle-aged and older adults on the International Clinical Trials Registry Platform (ICTRP).MethodsOsteoporosis-related RCTs registered on the ICTRP were searched on December 31, 2020. The main features of eligible RCTs were assessed. We searched PubMed, Google scholar, Medline, and Embase databases for the publication status of completed RCTs.ResultsA total of 537 osteoporosis-related RCTs were identified for analysis. The number of registered RCTs increased rapidly in 2005 (N = 47). Of these, 346 (64.4%) RCTs involved only women and 275 (51.2%) were retrospectively registered. Most RCTs were of open-label design (61.3%). The most common primary purpose of osteoporosis-related RCTs was treatment (72.3%). Intervention investigated was mainly focused on medication (62.8%), followed by lifestyle or education (19.0%), and dietary supplement (10.4%). After trial completion, the results of only 140 (35.5%) RCTs were available on the ICTRP, and the publication rate after trial completion was 30.5%.ConclusionsRCTs on osteoporosis among middle-aged and older adults were dominated by retrospectively registered and open-label trials. Most trials lacked available results and associated publications. More awareness of prospective registration and blinding design in osteoporosis-related RCTs is needed. Further, publication and dissemination of RCTs results should be promoted.

scholarly journals The Influences of Adherence to Tamoxifen and CYP2D6 Pharmacogenetics on Plasma Concentrations of the Active Metabolite (Z)‐Endoxifen in Breast Cancer

2019 ◽  
Vol 13 (2) ◽  
pp. 284-292 ◽  
Author(s):  
Jeanine Marie Nardin ◽  
Werner Schroth ◽  
Thais Abreu Almeida ◽  
Thomas Mürdter ◽  
Solane Picolotto ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Active Metabolite ◽  
Plasma Concentrations

scholarly journals Clinical trial registries as Scientometric data: A novel solution for linking and deduplicating clinical trials from multiple registries

2021 ◽  
Author(s):  
Christian Thiele ◽  
Gerrit Hirschfeld ◽  
Ruth von Brachel
Keyword(s):  
Clinical Trials ◽  
Random Forest ◽  
Random Forest Model ◽  
Scientometric Analysis ◽  
Data Set ◽  
The Public ◽  
Forest Model ◽  
Clinical Trial Registries ◽  
Multiple Primary ◽  
Clinical Trials Registry

AbstractRegistries of clinical trials are a potential source for scientometric analysis of medical research and serve important functions for the research community and the public at large. Clinical trials that recruit patients in Germany are usually registered in the German Clinical Trials Register (DRKS) or in international registries such as ClinicalTrials.gov. Furthermore, the International Clinical Trials Registry Platform (ICTRP) aggregates trials from multiple primary registries. We queried the DRKS, ClinicalTrials.gov, and the ICTRP for trials with a recruiting location in Germany. Trials that were registered in multiple registries were linked using the primary and secondary identifiers and a Random Forest model based on various similarity metrics. We identified 35,912 trials that were conducted in Germany. The majority of the trials was registered in multiple databases. 32,106 trials were linked using primary IDs, 26 were linked using a Random Forest model, and 10,537 internal duplicates on ICTRP were identified using the Random Forest model after finding pairs with matching primary or secondary IDs. In cross-validation, the Random Forest increased the F1-score from 96.4% to 97.1% compared to a linkage based solely on secondary IDs on a manually labelled data set. 28% of all trials were registered in the German DRKS. 54% of the trials on ClinicalTrials.gov, 43% of the trials on the DRKS and 56% of the trials on the ICTRP were pre-registered. The ratio of pre-registered studies and the ratio of studies that are registered in the DRKS increased over time.

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 Scaling Up: Multisite Open-Label Clinical Trials of MDMA-Assisted Therapy for Severe Posttraumatic Stress Disorder

2021 ◽  
pp. 002216782110236
Author(s):  
Julie B. Wang ◽  
Jessica Lin ◽  
Leah Bedrosian ◽  
Allison Coker ◽  
Ilsa Jerome ◽  
...  
Keyword(s):  
Posttraumatic Stress Disorder ◽  
Clinical Trials ◽  
Posttraumatic Stress ◽  
Clinical Supervision ◽  
Stress Disorder ◽  
The United States ◽  
Health Condition ◽  
Open Label ◽  
Adverse Health Outcomes ◽  
Ptsd Symptom Severity

Background: Posttraumatic stress disorder (PTSD) is a debilitating mental health condition associated with serious adverse health outcomes and functional impairment. Previous MDMA–assisted therapy (MDMA-AT) studies have shown promising results in single site studies. Two open-label studies tested this modality in multisite clinical trials to assess the feasibility of scaling this manualized therapy across 14 North American sites. Method: Cotherapist dyads were trained in the manualized MDMA-AT protocol and administered three experimental sessions 3 to 5 weeks apart among participants with severe PTSD. Cotherapist dyads were provided clinical supervision and evaluated for protocol adherence by centralized raters. Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) assessed change in symptoms severity. Results: Adherence rating scores were high across cotherapist dyads ( M = 95.08%, SD = 3.70%) and sites ( M = 95.23%, SD = 2.20%). CAPS-5 scores decreased following 3 MDMA-AT sessions at 18 weeks post baseline (Δ M = −29.99, Δ SD = 13.45, p < .0001, n = 37, Cohen’s d = 2.2, confidence interval [1.97, 2.47]). MDMA was well tolerated. Conclusions: These findings corroborate previous results that MDMA-AT can achieve significant improvements in PTSD symptom severity and demonstrate scalability of manualized therapy across clinic sites in the United States and Canada.

scholarly journals Effects of open-label placebos in clinical trials: a systematic review and meta-analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Melina von Wernsdorff ◽  
Martin Loef ◽  
Brunna Tuschen-Caffier ◽  
Stefan Schmidt
Keyword(s):  
Systematic Review ◽  
Clinical Trials ◽  
Medical Condition ◽  
Data Extraction ◽  
Meta Analysis ◽  
Risk Of Bias ◽  
Open Label ◽  
Cancer Related Fatigue ◽  
Promising Treatment ◽  
Irritable Bowel

AbstractOpen-label placebos (OLPs) are placebos without deception in the sense that patients know that they are receiving a placebo. The objective of our study is to systematically review and analyze the effect of OLPs in comparison to no treatment in clinical trials. A systematic literature search was carried out in February 2020. Randomized controlled trials of any medical condition or mental disorder comparing OLPs to no treatment were included. Data extraction and risk of bias rating were independently assessed. 1246 records were screened and thirteen studies were included into the systematic review. Eleven trials were eligible for meta-analysis. These trials assessed effects of OLPs on back pain, cancer-related fatigue, attention deficit hyperactivity disorder, allergic rhinitis, major depression, irritable bowel syndrome and menopausal hot flushes. Risk of bias was moderate among all studies. We found a significant overall effect (standardized mean difference = 0.72, 95% Cl 0.39–1.05, p < 0.0001, I2 = 76%) of OLP. Thus, OLPs appear to be a promising treatment in different conditions but the respective research is in its infancy. More research is needed, especially with respect to different medical and mental disorders and instructions accompanying the OLP administration as well as the role of expectations and mindsets.

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