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Yuen MF, Fung S, Ma X, Nguyen TT, Hassanein T, Hann HW, Elkhashab M, Nahass RG, Park JS, Jacobson IM, Ayoub WS, Han SH, Gane EJ, Zomorodi K, Yan R, Ma J, Knox SJ, Stamm LM, Bonacini M, Weilert F, Ramji A, Bennett M, Ravendhran N, Chan S, Dieterich DT, Kwo PY, Schiff ER, Bae HS, Lalezari J, Agarwal K, Sulkowski MS. Long-term open-label vebicorvir for chronic HBV infection: Safety and off-treatment responses. JHEP Rep 2024; 6:100999. [PMID: 38510983 PMCID: PMC10951643 DOI: 10.1016/j.jhepr.2023.100999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 12/18/2023] [Accepted: 12/20/2023] [Indexed: 03/22/2024] Open
Abstract
Background & Aims The investigational first-generation core inhibitor vebicorvir (VBR) demonstrated safety and antiviral activity over 24 weeks in two phase IIa studies in patients with chronic HBV infection. In this long-term extension study, patients received open-label VBR with nucleos(t)ide reverse transcriptase inhibitors (NrtIs). Methods Patients in this study (NCT03780543) previously received VBR + NrtI or placebo + NrtI in parent studies 201 (NCT03576066) or 202 (NCT03577171). After receiving VBR + NrtI for ≥52 weeks, stopping criteria (based on the treatment history and hepatitis B e antigen status in the parent studies) were applied, and patients either discontinued both VBR + NrtI, discontinued VBR only, or continued both VBR + NrtI. The primary efficacy endpoint was the proportion of patients with HBV DNA <20 IU/ml at 24 weeks off treatment. Results Ninety-two patients entered the extension study and received VBR + NrtI. Long-term VBR + NrtI treatment led to continued suppression of HBV nucleic acids and, to a lesser extent, HBV antigens. Forty-three patients met criteria to discontinue VBR + NrtI, with no patients achieving the primary endpoint; the majority of virologic rebound occurred ≥4 weeks off treatment. Treatment was generally well tolerated, with few discontinuations due to adverse events (AEs). There were no deaths. Most AEs and laboratory abnormalities were related to elevations in alanine aminotransferase and occurred during the off-treatment or NrtI-restart phases. No drug-drug interactions between VBR + NrtI and no cases of treatment-emergent resistance among patients who adhered to treatment were observed. Conclusions Long-term VBR + NrtI was safe and resulted in continued reductions in HBV nucleic acids following completion of the 24-week parent studies. Following treatment discontinuation, virologic relapse was observed in all patients. This first-generation core inhibitor administered with NrtI for at least 52 weeks was not sufficient for HBV cure. Clinical trial number NCT03780543. Impact and implications Approved treatments for chronic hepatitis B virus infection (cHBV) suppress viral replication, but viral rebound is almost always observed after treatment discontinuation, highlighting an unmet need for improved therapies with finite treatment duration producing greater therapeutic responses that can be sustained off treatment. First-generation core inhibitors, such as vebicorvir, have mechanisms of action orthogonal to standard-of-care therapies that deeply suppress HBV viral replication during treatment; however, to date, durable virologic responses have not been observed after treatment discontinuation. The results reported here will help researchers with the design and interpretation of future studies investigating core inhibitors as possible components of finite treatment regimens for patients with cHBV. It is possible that next-generation core inhibitors with enhanced potency may produce deeper and more durable antiviral activity than first-generation agents, including vebicorvir.
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Affiliation(s)
- Man-Fung Yuen
- Department of Medicine and State Key Laboratory of Liver Research, School of Clinical Medicine, Queen Mary Hospital, The University of Hong Kong, Hong Kong
| | - Scott Fung
- Department of Medicine, Division of Gastroenterology and Hepatology, University of Toronto, Toronto, Canada
| | - Xiaoli Ma
- Office of Xiaoli Ma, Philadelphia, PA, USA
| | - Tuan T. Nguyen
- T Nguyen Research and Education, Inc., San Diego, CA, USA
| | | | - Hie-Won Hann
- Department of Medicine, Division of Gastroenterology and Hepatology, Thomas Jefferson University Hospital, Philadelphia, PA, USA
| | | | | | | | | | | | - Steven-Huy Han
- Pfleger Liver Institute, University of California, Los Angeles, CA, USA
| | | | - Katie Zomorodi
- Assembly Biosciences, Inc., South San Francisco, CA, USA
| | - Ran Yan
- Assembly Biosciences, Inc., South San Francisco, CA, USA
| | - Julie Ma
- Assembly Biosciences, Inc., South San Francisco, CA, USA
| | - Steven J. Knox
- Assembly Biosciences, Inc., South San Francisco, CA, USA
| | - Luisa M. Stamm
- Assembly Biosciences, Inc., South San Francisco, CA, USA
| | | | | | - Alnoor Ramji
- GastroIntestinal Research Institute, Vancouver, Canada
| | | | | | | | - Douglas T. Dieterich
- Department of Medicine, Division of Liver Diseases, Icahn School of Medicine, Mount Sinai Hospital, New York, NY, USA
| | - Paul Yien Kwo
- Stanford University Medical Center, Stanford, CA, USA
| | - Eugene R. Schiff
- Schiff Center for Liver Diseases, University of Miami School of Medicine, Miami, FL, USA
| | - Ho S. Bae
- Asian Pacific Liver Center, Los Angeles, CA, USA
| | | | - Kosh Agarwal
- Institute of Liver Studies, King’s College Hospital, London, UK
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Agarwal K, Xu J, Gane EJ, Nguyen TT, Ding Y, Knox SJ, Alves K, Evanchik M, Zomorodi K, Ma J, Yan R, Huang Q, Colonno R, Stamm LM, Hassanein TI, Kim DJ, Lim YS, Yuen MF. Safety, pharmacokinetics and antiviral activity of ABI-H2158, a hepatitis B virus core inhibitor: A randomized, placebo-controlled phase 1 study. J Viral Hepat 2023; 30:209-222. [PMID: 36302125 DOI: 10.1111/jvh.13764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 09/14/2022] [Accepted: 10/16/2022] [Indexed: 01/14/2023]
Abstract
Treatment for chronic hepatitis B virus infection (cHBV) is mostly indefinite, with new finite-duration therapies needed. We report safety, pharmacokinetics and antiviral activity of the investigational HBV core inhibitor ABI-H2158. This Phase 1a/b study (NCT03714152) had three parts: Part A, participants received a single ascending oral dose of ABI-H2158 (5-500 mg) or placebo; Part B, participants received multiple doses of ABI-H2158 300 mg once (QD) or twice (BID) daily or placebo, for 10 days; Part C, cHBV patients received ABI-H2158 (100, 300, or 500 mg QD or 300 mg BID) or placebo, for 14 days. Ninety-three participants enrolled. In Parts A/B, there were no serious adverse events (SAEs) or deaths, and all treatment-emergent AEs (TEAEs) were Grade 1. In Part C, two patients had Grade 3 TEAEs unrelated to ABI-H2158; there were no deaths, SAEs or Grade 4 TEAEs. In Part A, median time to maximum ABI-H2158 plasma concentration (Tmax ) and mean terminal elimination half-life (t½ ) were 1-4 and 9.8-20.7 h, and area under the plasma concentration-time curve increased dose proportionally. In Part B, Day 10 Tmax was 2 h, mean t½ was 15.5-18.4 h, and exposure accumulated 1.7- to 3.1-fold. In Part C, Day 14 Tmax was 1 h, exposure accumulated 1.4- to 1.8-fold, and ABI-H2158 was associated with >2 log10 declines in HBV nucleic acids. In conclusion, ABI-H2158 in cHBV patients following 14 days of dosing was well tolerated and demonstrated potent antiviral activity. Safety and pharmacokinetics supported future QD dosing.
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Affiliation(s)
- Kosh Agarwal
- Institute of Liver Studies, King's College Hospital, London, UK
| | - Jia Xu
- Phase 1 Clinical Trials Unit, The First Hospital of Jilin University, Jilin, China
| | | | - Tuan T Nguyen
- T Nguyen Research and Education, Inc., San Diego, California, USA
| | - Yanhua Ding
- Phase 1 Clinical Trials Unit, The First Hospital of Jilin University, Jilin, China
| | - Steven J Knox
- Assembly Biosciences, Inc., South San Francisco, California, USA
| | - Katia Alves
- Assembly Biosciences, Inc., South San Francisco, California, USA
| | - Marc Evanchik
- Assembly Biosciences, Inc., South San Francisco, California, USA
| | - Katie Zomorodi
- Assembly Biosciences, Inc., South San Francisco, California, USA
| | - Julie Ma
- Assembly Biosciences, Inc., South San Francisco, California, USA
| | - Ran Yan
- Assembly Biosciences, Inc., South San Francisco, California, USA
| | - Qi Huang
- Assembly Biosciences, Inc., South San Francisco, California, USA
| | - Richard Colonno
- Assembly Biosciences, Inc., South San Francisco, California, USA
| | - Luisa M Stamm
- Assembly Biosciences, Inc., South San Francisco, California, USA
| | | | - Dong Joon Kim
- Hallym University Chuncheon Sacred Heart Hospital, Chuncheon, South Korea
| | - Young-Suk Lim
- Asan Medical Centre, University of Ulsan College of Medicine, Seoul, South Korea
| | - Man-Fung Yuen
- Department of Medicine, University of Hong Kong, Hong Kong, Hong Kong
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3
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Junnarkar G, Allphin C, Profant J, Steininger TL, Chen C, Zomorodi K, Skowronski R, Black J. Development of a lower-sodium oxybate formulation for the treatment of patients with narcolepsy and idiopathic hypersomnia. Expert Opin Drug Discov 2021; 17:109-119. [PMID: 34818123 DOI: 10.1080/17460441.2022.1999226] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
INTRODUCTION Sodium oxybate (SXB) is a standard of care for cataplexy, excessive daytime sleepiness, and disrupted nighttime sleep in narcolepsy. At recommended dosages in adults (6-9 g/night), SXB increases daily dietary intake of sodium by 1100-1640 mg. Because excess sodium intake is associated with increased blood pressure and cardiovascular risk, an oxybate formulation containing 92% less sodium than SXB (lower-sodium oxybate; LXB) was developed to provide an alternative oxybate treatment option. In 2020, LXB was approved for treatment of cataplexy or excessive daytime sleepiness in patients 7 years of age and older with narcolepsy, and in 2021, for treatment of idiopathic hypersomnia in adults. AREAS COVERED Development of LXB from initial concept to regulatory approval is described, including formulation development and preclinical and clinical studies. Pharmacokinetic parameters and bioequivalence evaluations from phase 1 clinical trials are detailed. Efficacy and safety results from phase 3 clinical trials of LXB in patients with narcolepsy or idiopathic hypersomnia are presented and discussed. EXPERT OPINION Reducing sodium from high sodium‒containing medications is an important step to offset cardiovascular risks associated with high sodium consumption. The development of LXB exemplifies the importance of a collaborative approach to drug development, with patient needs paramount. PLAIN LANGUAGE SUMMARY Sodium oxybate (Xyrem®) is a medication for people with narcolepsy aged 7 years and older. Xyrem treats symptoms of excessive daytime sleepiness (EDS) or cataplexy (attacks of muscle weakness caused by emotion) in narcolepsy. At the recommended dosages in adults, Xyrem adds a large amount of sodium to daily dietary intake. Too much sodium in the diet is associated with increased blood pressure and risks of damage to the heart and blood vessels. Researchers used calcium, magnesium, and potassium ions in addition to a small amount of sodium to make a new oxybate medication, called Xywav®, that has 92% less sodium than Xyrem. Xywav and Xyrem were similar in laboratory and animal studies. In people, the body absorbs and processes Xywav slightly differently than Xyrem, but Xywav treatment has been shown to work the same to reduce symptoms of cataplexy and EDS in people with narcolepsy and is approved by the US Food and Drug Administration. Another neurological disorder with EDS is called idiopathic hypersomnia. Based on a clinical study, Xywav also reduced EDS and other symptoms in people with idiopathic hypersomnia. Side effects with Xywav are similar to those seen in previous studies with Xyrem.
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Affiliation(s)
- Gunjan Junnarkar
- Pharmaceutical Development and Manufacturing Science, Jazz Pharmaceuticals, Inc., Palo Alto, CA, USA
| | - Clark Allphin
- New Product and Technology Integration, Jazz Pharmaceuticals, Inc., Palo Alto, CA, USA
| | - Judi Profant
- Medical Affairs, Global Molecule Team, Jazz Pharmaceuticals, Inc., Palo Alto, CA, USA
| | - Teresa L Steininger
- Medical Communications, Global Scientific Affairs, Jazz Pharmaceuticals, Inc., Palo Alto, CA, USA
| | - Cuiping Chen
- Neuroscience Clinical Pharmacology, Jazz Pharmaceuticals, Inc., Palo Alto, CA, USA
| | - Katie Zomorodi
- Early Development and Clinical Pharmacology, Jazz Pharmaceuticals, Inc., Palo Alto, CA, USA
| | - Roman Skowronski
- Clinical Development, Jazz Pharmaceuticals, Inc., Palo Alto, CA, USA
| | - Jed Black
- Stanford University Center for Sleep Sciences and Medicine, Palo Alto, CA, USA.,Sleep and CNS Medicine, Jazz Pharmaceuticals, Inc., Palo Alto, CA, USA
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Lin T, Dumas T, Kaullen J, Berry NS, Choi MR, Zomorodi K, Silverman JA. Population Pharmacokinetic Model Development and Simulation for Recombinant Erwinia Asparaginase Produced in Pseudomonas fluorescens (JZP-458). Clin Pharmacol Drug Dev 2021; 10:1503-1513. [PMID: 34310867 PMCID: PMC9292349 DOI: 10.1002/cpdd.1002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 06/21/2021] [Indexed: 11/17/2022]
Abstract
JZP‐458 is a recombinant Erwinia asparaginase produced using a novel Pseudomonas fluorescens expression platform that yields an enzyme expected to lack immunologic cross‐reactivity to Escherichia coli–derived asparaginases. It is being developed as part of a multiagent chemotherapeutic regimen to treat acute lymphoblastic leukemia or lymphoblastic lymphoma patients who develop E coli–derived asparaginase hypersensitivity. A population pharmacokinetic (PopPK) model was developed for JZP‐458 using serum asparaginase activity (SAA) data from a phase 1, single‐dose study (JZP458‐101) in healthy adults. Effects of intrinsic covariates (body weight, body surface area, age, sex, and race) on JZP‐458 PK were evaluated. The model included SAA data from 24 healthy adult participants from the phase 1 study who received JZP‐458: intramuscular (IM) data at 12.5 mg/m2 (N = 6) and 25 mg/m2 (N = 6), and intravenous (IV) data at 25 mg/m2 (N = 6) and 37.5 mg/m2 (N = 6). Model simulations of adult and pediatric SAA profiles were performed to explore the likelihood of achieving a therapeutic target nadir SAA (NSAA) level ≥0.1 IU/mL based on different administration strategies. PopPK modeling and simulation suggest JZP‐458 is expected to achieve 72‐hour NSAA levels ≥0.1 IU/mL in 100% of adult or pediatric populations receiving IM administration at 25 mg/m2, and in 80.9% of adult and 94.5% of pediatric populations receiving IV administration at 37.5 mg/m2 on a Monday/Wednesday/Friday (M/W/F) dosing schedule. Based on these results, the recommended starting dose for the phase 2/3 pivotal study is 25 mg/m2 IM or 37.5 mg/m2 IV on a M/W/F dosing schedule in pediatric and adult patients.
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Affiliation(s)
- Tong Lin
- Jazz Pharmaceuticals, Palo Alto, California, USA
| | | | | | | | - Mi Rim Choi
- Jazz Pharmaceuticals, Palo Alto, California, USA
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5
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Videnovic A, Amara AW, Comella C, Schweitzer PK, Emsellem H, Liu K, Sterkel AL, Gottwald MD, Steinerman JR, Jochelson P, Zomorodi K, Hauser RA. Solriamfetol for Excessive Daytime Sleepiness in Parkinson's Disease: Phase 2 Proof-of-Concept Trial. Mov Disord 2021; 36:2408-2412. [PMID: 34191352 PMCID: PMC8596433 DOI: 10.1002/mds.28702] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 06/04/2021] [Accepted: 06/08/2021] [Indexed: 11/29/2022] Open
Abstract
Background Solriamfetol is approved (US and EU) for excessive daytime sleepiness (EDS) in narcolepsy and obstructive sleep apnea. Objectives Evaluate solriamfetol safety/efficacy for EDS in Parkinson's disease (PD). Methods Phase 2, double‐blind, 4‐week, crossover trial: adults with PD and EDS were randomized to sequence A (placebo, solriamfetol 75, 150, 300 mg/d), B (solriamfetol 75, 150, 300 mg/d, placebo), or C (placebo). Outcomes (safety/tolerability [primary]; Epworth Sleepiness Scale [ESS]; Maintenance of Wakefulness Test [MWT]) were assessed weekly. P values are nominal. Results Common adverse events (n = 66): nausea (10.7%), dizziness (7.1%), dry mouth (7.1%), headache (7.1%), anxiety (5.4%), constipation (5.4%), dyspepsia (5.4%). ESS decreased both placebo (−4.78) and solriamfetol (−4.82 to −5.72; P > 0.05). MWT improved dose‐dependently with solriamfetol, increasing by 5.05 minutes with 300 mg relative to placebo (P = 0.0098). Conclusions Safety/tolerability was consistent with solriamfetol's known profile. There were no significant improvements on ESS; MWT results suggest possible benefit with solriamfetol in PD. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society
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Affiliation(s)
- Aleksandar Videnovic
- Movement Disorders Unit and Division of Sleep Medicine, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Amy W Amara
- Division of Movement Disorders, Department of Neurology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Cynthia Comella
- Parkinson's Disease and Movement Disorders Program, Rush University, Chicago, Illinois, USA
| | - Paula K Schweitzer
- Sleep Medicine and Research Center, St. Luke's Hospital, Chesterfield, Missouri, USA
| | - Helene Emsellem
- The Center for Sleep & Wake Disorders, Chevy Chase, Maryland, USA
| | - Kris Liu
- Jazz Pharmaceuticals, Palo Alto, California, USA
| | | | | | | | | | | | - Robert A Hauser
- Parkinson's Disease and Movement Disorders Center, University of South Florida, Tampa, Florida, USA
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Chen C, Jenkins J, Zomorodi K, Skowronski R. Pharmacokinetics, bioavailability, and bioequivalence of lower-sodium oxybate in healthy participants in two open-label, randomized, crossover studies. Clin Transl Sci 2021; 14:2278-2287. [PMID: 34121333 PMCID: PMC8604214 DOI: 10.1111/cts.13087] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 04/29/2021] [Accepted: 05/18/2021] [Indexed: 11/28/2022] Open
Abstract
American Academy of Sleep Medicine practice parameters designate sodium oxybate (SXB) as a standard of care for cataplexy, excessive daytime sleepiness (EDS), and disrupted night‐time sleep in narcolepsy. Recently, a lower‐sodium oxybate (LXB) with 92% less sodium than SXB was approved in the United States for the treatment of cataplexy or EDS in patients 7 years of age and older with narcolepsy. Two phase I, open‐label, randomized, single‐dose crossover pharmacokinetic studies in healthy adults were conducted. Single 4.5‐g oral doses of LXB and SXB were administered in a fasted or fed state. In the fasted state at equivalent oxybate doses, LXB, compared with SXB, had a lower maximum plasma concentration (Cmax; study 1 [total aqueous volume, 240 ml]: 101.8 vs. 135.7 µg/ml; study 2 [60 ml]: 94.6 vs. 123.0 μg/ml), delayed time to Cmax (Tmax; study 1: 0.75 vs. 0.5 h; study 2: 1.0 vs. 0.5 h), but similar area under the curve (AUC; study 1: AUC0‐t, 235.4 vs. 263.9 μg∙h/ml; AUC0‐∞, 236.5 vs. 265.2 μg∙h/ml; study 2: AUC0‐t, 241.5 vs. 254.7 μg∙h/ml; AUC0‐∞, 243.1 vs. 256.3 μg∙h/ml). Bioequivalence criteria were met for AUC but not Cmax (both studies). Cmax and AUC were lower under fed than fasted conditions (LXB and SXB); differences between fed versus fasted were smaller for LXB than SXB. These pharmacokinetic differences between LXB and SXB are likely due to the lower sodium content in LXB. Pooled analyses demonstrated that a higher Cmax is associated with a higher incidence of nausea and vomiting.
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Affiliation(s)
- Cuiping Chen
- Jazz Pharmaceuticals, Inc, Palo Alto, California, USA
| | - Jack Jenkins
- Jazz Pharmaceuticals, Inc, Palo Alto, California, USA
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Zomorodi K, Chen D, Lee L, Swearingen D, Carter LP. A Randomized, Double-Blind, Placebo- and Positive-Controlled, 4-Period Crossover Study of the Effects of Solriamfetol on QTcF Intervals in Healthy Participants. Clin Pharmacol Drug Dev 2020; 10:404-413. [PMID: 32935460 PMCID: PMC8048583 DOI: 10.1002/cpdd.867] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 08/17/2020] [Indexed: 01/14/2023]
Abstract
Solriamfetol, a dopamine and norepinephrine reuptake inhibitor, is approved (United States and European Union; Sunosi) to treat excessive daytime sleepiness associated with narcolepsy (75‐150 mg/day) or obstructive sleep apnea (37.5‐150 mg/day). A thorough QT/QTc study assessed solriamfetol effects on QT interval (Fridericia correction for heart rate; QTcF). This randomized, double‐blind, placebo‐ and positive‐controlled, 4‐period crossover study compared single doses of 300 and 900 mg solriamfetol, 400 mg moxifloxacin, and placebo in healthy adults. Placebo‐ and predose‐adjusted mean differences in QTcF (ddQTcF; primary end point) were analyzed, and solriamfetol pharmacokinetics were characterized. Fifty‐five participants completed all periods. Upper bounds of 2‐sided 90% confidence intervals (CIs) for ddQTcF for both solriamfetol doses were <10 milliseconds at all postdose time points. Assay sensitivity was demonstrated with moxifloxacin; lower bounds of 2‐sided 90%CIs for ddQTcF > 5 milliseconds at 1, 2, and 3 hours postdose. There were no QTcF increases > 60 milliseconds or QTcF values > 480 milliseconds at either solriamfetol dose. Solriamfetol median tmax was 2‐3 hours; exposure was dose‐proportional. More participants experienced adverse events (AEs) after solriamfetol 900 versus 300 mg (70% vs 29%); none were serious (all mild/moderate), and there were no deaths. Common AEs were nausea, dizziness, and palpitations. Neither solriamfetol dose resulted in QTcF prolongation > 10 milliseconds.
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Affiliation(s)
| | - Dan Chen
- Jazz Pharmaceuticals, Palo Alto, California, USA
| | - Lawrence Lee
- Jazz Pharmaceuticals, Palo Alto, California, USA
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8
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Chen C, Rosen CL, Ruoff C, Boyce LH, Parvataneni R, Zomorodi K, Brantley S, Sale M, Plazzi G. Population and Noncompartmental Pharmacokinetics of Sodium Oxybate Support Weight-Based Dosing in Children and Adolescents With Narcolepsy With Cataplexy. Clin Transl Sci 2020; 13:932-940. [PMID: 32216084 PMCID: PMC7485950 DOI: 10.1111/cts.12780] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 02/09/2020] [Indexed: 11/29/2022] Open
Abstract
The pharmacokinetics (PKs) of sodium oxybate (SXB) was evaluated in a subset of participants from a study of SXB treatment in children (aged 7–11 years; n = 11) and adolescents (aged 12–17 years; n = 18) with narcolepsy with cataplexy. PK evaluation was conducted over 2 nights during the period when participants received a stable nightly SXB dose. The SXB dose on night 1 was half of night 2 and was administered in two equally divided doses: dose 1 was administered > 2 hours after the evening meal, and dose 2 was administered ≥ 4 hours after dose 1. Noncompartmental PK analysis demonstrated higher plasma concentrations post‐dose 2 vs. post‐dose 1, higher than dose‐proportional increases in area under the concentration‐time curve from 0 to 4 hours (AUC0–4h) after dose 1, indicating nonlinear clearance, and better correlation between exposure and mg/kg than exposure and gram dose. To confirm the noncompartmental findings, identify factors affecting SXB PK, and compare with prior results in adults, a population PK (PopPK) model was established combining PK data from the current study with prior data from adults (132 healthy volunteers and 13 with narcolepsy). A two‐compartment PopPK model with first‐order absorption and nonlinear clearance from the central compartment described the data well. PopPK identified weight as the main intrinsic factor and food as the main extrinsic factor affecting SXB PK, and predicts similar PK profiles on a mg/kg basis across ages. These results, along with previously reported efficacy and safety outcomes, support weight‐based SXB dose initiation in pediatric patients.
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Affiliation(s)
- Cuiping Chen
- Jazz Pharmaceuticals, Palo Alto, California, USA
| | - Carol L Rosen
- Division of Pediatric Pulmonology and Sleep Medicine, Rainbow Babies & Children's Hospital, Cleveland, Ohio, USA
| | - Chad Ruoff
- Stanford University Sleep Medicine Center, Redwood City, California, USA
| | - Leslie H Boyce
- Raleigh Neurology Associates, Raleigh, North Carolina, USA
| | | | | | | | - Mark Sale
- Nuventra Pharma Sciences, Durham, North Carolina, USA
| | - Giuseppe Plazzi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.,IRCSS, Istituto delle Scienze Neurologiche, Bologna, Italy
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Chen C, Skowronski R, Jenkins J, Zomorodi K. Pharmacokinetics, relative bioavailability and food effect of JZP-258 and sodium oxybate: results of two phase 1, open-label, randomised crossover studies in healthy volunteers. Sleep Med 2019. [DOI: 10.1016/j.sleep.2019.11.179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Zomorodi K, Chen D, Lee L, Lasseter K, Marbury T. Single-Dose Pharmacokinetics and Safety of Solriamfetol in Participants With Normal or Impaired Renal Function and With End-Stage Renal Disease Requiring Hemodialysis. J Clin Pharmacol 2019; 59:1120-1129. [PMID: 30865315 PMCID: PMC6618134 DOI: 10.1002/jcph.1402] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 01/30/2019] [Indexed: 01/05/2023]
Abstract
Solriamfetol (JZP‐110), a selective dopamine and norepinephrine reuptake inhibitor with wake‐promoting effects, is renally excreted ∼90% unchanged within 48 hours. Effects of renal impairment and hemodialysis on the pharmacokinetics and safety of 75‐mg single‐dose solriamfetol were evaluated in adults with normal renal function (n = 6); mild (n = 6), moderate (n = 6), or severe (n = 6) renal impairment; and end‐stage renal disease (ESRD) with and without hemodialysis (n = 7). Relative to normal renal function, geometric mean area under the plasma concentration–time curve from time zero to infinity increased 53%, 129%, and 339%, and mean half‐life was 1.2‐, 1.9‐, and 3.9‐fold higher with mild, moderate, and severe renal impairment, respectively. Renal excretion of unchanged solriamfetol over 48 hours was 85.8%, 80.0%, 66.4%, and 57.1% in normal, mild, moderate, and severe renal impairment groups, respectively; mean maximum concentration and time to maximum concentration did not vary substantially. Decreases in solriamfetol clearance were proportional to decreases in estimated glomerular filtration rate. Geometric mean area under the plasma concentration–time curve from time zero to time of last quantifiable concentration increased 357% and 518% vs normal in ESRD with and without hemodialysis, respectively, with half‐life >100 hours in both groups. Over the 4‐hour hemodialysis period, ∼21% of solriamfetol dose was removed. Adverse events included headache (n = 1) and nausea (n = 1). Six days after dosing, 1 participant had increased alanine and aspartate aminotransferase, leading to study discontinuation. While these adverse events were deemed study‐drug related, they were mild and resolved. Results from this study combined with population pharmacokinetic modeling/simulation suggest that solriamfetol dosage adjustments are necessary in patients with moderate or severe but not with mild renal impairment. Due to significant exposure increase/prolonged half‐life, dosing is not recommended in patients with ESRD.
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Affiliation(s)
| | - Dan Chen
- Jazz PharmaceuticalsPalo AltoCAUSA
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Zomorodi K, Kankam M, Lu Y. A Phase I, Randomized, Crossover, Open-label Study of the Pharmacokinetics of Solriamfetol (JZP-110) in Healthy Adult Subjects With and Without Food. Clin Ther 2019; 41:196-204. [DOI: 10.1016/j.clinthera.2018.12.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 11/20/2018] [Accepted: 12/03/2018] [Indexed: 11/16/2022]
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Rosen CL, Ruoff C, Boyce LH, Chen C, Wang Y, Parvataneni R, Zomorodi K, Plazzi G. 0837 Pharmacokinetics of Sodium Oxybate in Children and Adolescents with Narcolepsy with Cataplexy. Sleep 2018. [DOI: 10.1093/sleep/zsy061.836] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- C L Rosen
- Division of Pediatric Pulmonology and Sleep Medicine, Rainbow Babies & Children’s Hospital, Cleveland, OH
| | - C Ruoff
- Stanford University Sleep Medicine Center, Redwood City, CA
| | - L H Boyce
- Raleigh Neurology Associates, Raleigh, NC
| | - C Chen
- Jazz Pharmaceuticals, Palo Alto, CA
| | - Y Wang
- Jazz Pharmaceuticals, Palo Alto, CA
| | | | | | - G Plazzi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, ITALY
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Zomorodi K, Chen D, Lee L, Lasseter K, Marbury T. 1027 AN OPEN-LABEL, SINGLE-DOSE, PHASE 1 STUDY OF THE PHARMACOKINETICS AND SAFETY OF JZP-110 IN SUBJECTS WITH NORMAL OR IMPAIRED RENAL FUNCTION AND WITH END-STAGE RENAL DISEASE REQUIRING HEMODIALYSIS. Sleep 2017. [DOI: 10.1093/sleepj/zsx050.1026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Tocchetti P, Tudone E, Marier JF, Marbury TC, Zomorodi K, Eller M. Pharmacokinetic profile of defibrotide in patients with renal impairment. Drug Des Devel Ther 2016; 10:2631-41. [PMID: 27574402 PMCID: PMC4993270 DOI: 10.2147/dddt.s112181] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Hepatic veno-occlusive disease, also called sinusoidal obstruction syndrome (VOD/SOS), is an unpredictable, potentially life-threatening complication of hematopoietic stem cell transplant conditioning. Severe VOD/SOS, generally associated with multiorgan dysfunction (pulmonary or renal dysfunction), may be associated with >80% mortality. Defibrotide, recently approved in the US, has demonstrated efficacy treating hepatic VOD/SOS with multiorgan dysfunction. Because renal impairment is prevalent in patients with VOD/SOS, this Phase I, open-label, two-part study in adults examined the effects of hemodialysis and severe or end-stage renal disease (ESRD) on defibrotide pharmacokinetics (PK). Part 1 compared defibrotide PK during single 6.25 mg/kg doses infused with and without dialysis. Part 2 assessed defibrotide plasma PK after multiple 6.25 mg/kg doses in nondialysis-dependent subjects with severe/ESRD versus healthy matching subjects. Among six subjects enrolled in Part 1, percent ratios of least-squares mean and 90% confidence intervals (CIs) on dialysis and nondialysis days were 109.71 (CI: 97.23, 123.78) for maximum observed plasma concentration (Cmax); 108.39 (CI: 97.85, 120.07) for area under the concentration–time curve to the time of the last quantifiable plasma concentration (AUC0–t); and 109.98 (CI: 99.39, 121.70) for AUC extrapolated to infinity (AUC0–∞). These ranges were within 80%–125%, indicating no significant effect of dialysis on defibrotide exposure/clearance. In Part 2, defibrotide exposure parameters in six subjects with severe/ESRD after multiple doses (AUC0–t, 113 µg·h/mL; AUC over dosing interval, 113 µg·h/mL; Cmax, 53.8 µg/mL) were within 5%–8% of parameters after the first dose (AUC0–t, 117 µg·h/mL; AUC0–∞, 118 µg·h/mL; Cmax, 54.9 µg/mL), indicating no accumulation. Defibrotide peak and extent of exposures in those with severe/ESRD were ~35%–37% and 50%–60% higher, respectively, versus controls, following single and multiple doses. One adverse event (vomiting, possibly drug-related) was reported. These findings support defibrotide prescribing guidance stating no dose adjustment is necessary for hemodialysis or severe/ESRD.
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Affiliation(s)
| | - Elena Tudone
- Clinical Operations, Gentium, Villa Guardia, Como, Italy
| | - Jean-Francois Marier
- Reporting and Analysis Services, Pharsight, a Certara Company, Montreal, Quebec, Canada
| | | | - Katie Zomorodi
- Early Development and Clinical Pharmacology, Jazz Pharmaceuticals
| | - Mark Eller
- Early Drug Development, Jazz Pharmaceuticals, Palo Alto, CA, USA
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LeWitt PA, Huff FJ, Hauser RA, Chen D, Lissin D, Zomorodi K, Cundy KC. Double-blind study of the actively transported levodopa prodrug XP21279 in Parkinson's disease. Mov Disord 2013; 29:75-82. [DOI: 10.1002/mds.25742] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 09/25/2013] [Accepted: 10/01/2013] [Indexed: 11/11/2022] Open
Affiliation(s)
- Peter A. LeWitt
- Department of Neurology; Henry Ford Hospital; West Bloomfield Michigan USA
- Department of Neurology; Wayne State University School of Medicine; Detroit Michigan USA
| | | | - Robert A. Hauser
- Parkinson's Disease and Movement Disorders Center; University of South Florida; Tampa Florida USA
| | - Dan Chen
- XenoPort, Inc.; Santa Clara California USA
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16
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Marina NM, Cochrane D, Harney E, Zomorodi K, Blaney S, Winick N, Bernstein M, Link MP. Dose escalation and pharmacokinetics of pegylated liposomal doxorubicin (Doxil) in children with solid tumors: a pediatric oncology group study. Clin Cancer Res 2002; 8:413-8. [PMID: 11839657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
PURPOSE To determine the maximum tolerated dose and pharmacokinetics of Doxil in children with recurrent or refractory solid tumors. Doxil is pegylated doxorubicin. EXPERIMENTAL DESIGN Eligible patients were children with refractory tumors who had received cumulative anthracycline doses <300 mg/m(2). Cohorts of at least three patients each received escalating doses of Doxil starting at 40 mg/m(2) at 4-week intervals. If no dose-limiting toxicity occurred, dosages were escalated by increments of 10 mg/m(2) in subsequent cohorts. Originally, Doxil was administered over 60 min, but significant infusion reactions prompted longer infusion times of 4 h. Patients also received premedication with dexamethasone, ranitidine, and diphenhydramine 24 h before infusion, with ranitidine continued 24 h after infusion. Periodic blood samples were collected and plasma doxorubicin concentrations were quantified to characterize the pharmacokinetics of Doxil. RESULTS Between January 1997 and June 2000, 22 children ages 4-21 years with refractory tumors were treated with Doxil. Most patients had received one to five prior chemotherapy regimens, and all but five had prior radiotherapy (two had no prior therapy). Doxil was escalated to a dosage of 70 mg/m(2). At that level, dose-limiting mucositis was seen during the first cycle in two of six patients, thus defining dose-limiting toxicity, and in one additional patient during a subsequent cycle. Grade 4 neutropenia lasting less than 7 days was documented in two of six patients. The dose-limiting toxicity among two of six patients at 70 mg/m(2) was grade 3 mucositis during the first cycle of therapy. Painful desquamating dermatitis of the hands and feet, palmar-plantar erythrodysesthesia, occurred in six patients. In two of those patients, palmar-plantar erythrodysesthesia started as grade 1 and progressed to grade 2 during subsequent courses. Mean estimates of central volume of distribution, clearance, and elimination half-life were 1.45 liters/m(2), 0.03 liter/h/m(2), and 36.4 h, respectively. CONCLUSION The maximum tolerated dose of Doxil administered every 4 weeks to pediatric patients was 60 mg/m(2). The effect of Doxil on pediatric patients with malignancies remains to be determined and should be studied in pediatric Phase II trials.
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Affiliation(s)
- Neyssa M Marina
- Department of Pediatrics, Stanford University Medical Center, Stanford, CA 94305-5208, USA.
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Barr J, Egan TD, Sandoval NF, Zomorodi K, Cohane C, Gambus PL, Shafer SL. Propofol dosing regimens for ICU sedation based upon an integrated pharmacokinetic-pharmacodynamic model. Anesthesiology 2001; 95:324-33. [PMID: 11506101 DOI: 10.1097/00000542-200108000-00011] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The pharmacology of propofol infusions administered for long-term sedation of intensive care unit (ICU) patients has not been fully characterized. The aim of the study was to develop propofol dosing guidelines for ICU sedation based on an integrated pharmacokinetic-pharmacodynamic model of propofol infusions in ICU patients. METHODS With Institutional Review Board approval, 30 adult male medical and surgical ICU patients were given target-controlled infusions of propofol for sedation, adjusted to maintain a Ramsay sedation scale score of 2-5. Propofol administration in the first 20 subjects was based on a previously derived pharmacokinetic model for propofol. The last 10 subjects were given propofol based on a pharmacokinetic model derived from the first 20 subjects. Plasma propofol concentrations were measured, together with sedation score. Population pharmacokinetic and pharmacodynamic parameters were estimated by means of nonlinear regression analysis in the first 20 subjects, then prospectively tested in the last 10 subjects. An integrated pharmacokinetic-pharmacodynamic model was used to construct dosing regimens for light and deep sedation with propofol in ICU patients. RESULTS The pharmacokinetics of propofol were described by a three-compartment model with lean body mass and fat body mass as covariates. The pharmacodynamics of propofol were described by a sigmoid model, relating the probability of sedation to plasma propofol concentration. The pharmacodynamic model for propofol predicted light and deep levels of sedation with 73% accuracy. Plasma propofol concentrations corresponding to the probability modes for sedation scores of 2, 3, 4, and 5 were 0.25, 0.6, 1.0, and 2.0 microg/ml. Predicted emergence times in a typical subject after 24 h, 72 h, 7 days, and 14 days of light sedation (sedation score = 3 --> 2) with propofol were 13, 34, 198, and 203 min, respectively. Corresponding emergence times from deep sedation (sedation score = 5 --> 2) with propofol were 25, 59, 71, and 74 h. CONCLUSIONS Emergence time from sedation with propofol in ICU patients varies with the depth of sedation, the duration of sedation, and the patient's body habitus. Maintaining a light level of sedation ensures a rapid emergence from sedation with long-term propofol administration.
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Affiliation(s)
- J Barr
- Department of Anesthesia, Stanford University, VA Palo Alto Health Care System, California 94304, USA.
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Barr J, Zomorodi K, Bertaccini EJ, Shafer SL, Geller E. A double-blind, randomized comparison of i.v. lorazepam versus midazolam for sedation of ICU patients via a pharmacologic model. Anesthesiology 2001; 95:286-98. [PMID: 11506097 DOI: 10.1097/00000542-200108000-00007] [Citation(s) in RCA: 139] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Benzodiazepines, such as lorazepam and midazolam, are frequently administered to surgical intensive care unit (ICU) patients for postoperative sedation. To date, the pharmacology of lorazepam in critically ill patients has not been described. The aim of the current study was to characterize and compare the pharmacokinetics and pharmacodynamics of lorazepam and midazolam administered as continuous intravenous infusions for postoperative sedation of surgical ICU patients. METHODS With Institutional Review Board approval, 24 consenting adult surgical patients were given either lorazepam or midazolam in a double-blind fashion (together with either intravenous fentanyl or epidural morphine for analgesia) through target-controlled intravenous infusions titrated to maintain a moderate level of sedation for 12-72 h postoperatively. Moderate sedation was defined as a Ramsay Sedation Scale score of 3 or 4. Sedation scores were measured, together with benzodiazepine plasma concentrations. Population pharmacokinetic and pharmacodynamic parameters were estimated using nonlinear mixed-effects modeling. RESULTS A two-compartment model best described the pharmacokinetics of both lorazepam and midazolam. The pharmacodynamic model predicted depth of sedation for both midazolam and lorazepam with 76% accuracy. The estimated sedative potency of lorazepam was twice that of midazolam. The predicted C50,ss (plasma benzodiazepine concentrations where P(Sedation > or = ss) = 50%) values for midazolam (sedation score [SS] > or = n, where n = a Ramsay Sedation Score of 2, 3, ... 6) were 68, 101, 208, 304, and 375 ng/ml. The corresponding predicted C50,ss values for lorazepam were 34, 51, 104, 152, and 188 ng/ml, respectively. Age, fentanyl administration, and the resolving effects of surgery and anesthesia were significant covariates of benzodiazepine sedation. The relative amnestic potency of lorazepam to midazolam was 4 (observed). The predicted emergence times from sedation after a 72-h benzodiazepine infusion for light (SS = 3) and deep (SS = 5) sedation in a typical patient were 3.6 and 14.9 h for midazolam infusions and 11.9 and 31.1 h for lorazepam infusions, respectively. CONCLUSIONS The pharmacology of intravenous infusions of lorazepam differs significantly from that of midazolam in critically ill patients. This results in significant delays in emergence from sedation with lorazepam as compared with midazolam when administered for ICU sedation.
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Affiliation(s)
- J Barr
- VA Palto Alto Health Care System, Stanford University School of Medicine, Anesthesiology Service, California 94304, USA.
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Somma J, Donner A, Zomorodi K, Sladen R, Ramsay J, Geller E, Shafer SL. Population pharmacodynamics of midazolam administered by target controlled infusion in SICU patients after CABG surgery. Anesthesiology 1998; 89:1430-43. [PMID: 9856718 DOI: 10.1097/00000542-199812000-00021] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Midazolam is used commonly for sedation in the surgical intensive care unit. A suboptimal dosing regimen may lead to relative overdosing, which could result in delayed extubation and increased cost. This multicenter trial characterized midazolam pharmacodynamics in patients recovering from coronary artery bypass grafting. METHODS Three centers enrolled 90 patients undergoing coronary artery bypass grafting. All patients received sufentanil and midazolam via target-controlled infusion. After surgery, midazolam was titrated to a Ramsay sedation score of 5 for 2 h and then decreased to maintain a sedation score of 3 or 4 for at least another 4 h. Pharmacodynamic parameters were derived using NONMEM. The model was cross-validated to test performance. RESULTS The probability of a given level of sedation was related to the midazolam concentration by this equation: P(Sedation > or = ss) = Cn/(Cn + C(50,ss)n), where ss is the sedation score, C is the sum of the midazolam concentration and a term reflecting the dissipating effect of anesthesia: C = [midazolam] + theta x e(-Kt), where theta = 256 ng/ml and K = 0.19 h(-1). C(50,ss) values for Ramsay scores of 2 to 6 were 5.7, 71, 171, 260, and 659 ng/ml, respectively. The model predicted 57% of the data points correctly and 88% within one sedation score. CONCLUSIONS Despite previous reports of high interindividual variability in midazolam pharmacodynamics in patients in the surgical intensive care unit, these cross-validation results suggest that, when midazolam is administered using a target-controlled infusion device, the level of sedation can be predicted within 1 sedation score in 88% of patients based on the target midazolam concentration and the time since the conclusion of the anesthetic.
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Affiliation(s)
- J Somma
- Department of Anesthesia, Stanford University, California, USA
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Zomorodi K, Donner A, Somma J, Barr J, Sladen R, Ramsay J, Geller E, Shafer SL. Population pharmacokinetics of midazolam administered by target controlled infusion for sedation following coronary artery bypass grafting. Anesthesiology 1998; 89:1418-29. [PMID: 9856717 DOI: 10.1097/00000542-199812000-00020] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Midazolam is commonly used for short-term postoperative sedation of patients undergoing cardiac surgery. The purpose of this multicenter study was to characterize the pharmacokinetics and intersubject variability of midazolam in patients undergoing coronary artery bypass grafting. METHODS With institutional review board approval, 90 consenting patients undergoing coronary artery bypass grafting were enrolled at three study centers. All subjects received sufentanil and midazolam via target-controlled infusions. After operation, midazolam was titrated to maintain deep sedation for at least 2 h. It was then titrated downward to decrease sedation for a minimum of 4 h more and was discontinued before tracheal extubation. Arterial blood samples were taken throughout the study and were assayed for midazolam and 1-hydroxymidazolam. Midazolam population pharmacokinetic parameters were estimated using NONMEM. Cross-validation was used to estimate the performance of the model. RESULTS The pharmacokinetics of midazolam were best described by a simple three-compartment mammillary model. Typical pharmacokinetic parameters were V1 = 32.2 l, V2 = 53 l, V3 = 245 l, Cl1 = 0.43 l/min, Cl2 = 0.56 l/min, and Cl3 = 0.39 l/min. The calculated elimination half-life was 15 h. The median absolute prediction error was 25%, with a bias of 1.4%. The performance in the cross-validation was similar. Midazolam metabolites were clinically insignificant in all patients. CONCLUSIONS The intersubject variability and predictability of the three-compartment pharmacokinetic model are similar to those of other intravenous anesthetic drugs. This multicenter study did not confirm previous studies of exceptionally large variability of midazolam pharmacokinetics when used for sedation in intensive care settings.
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Affiliation(s)
- K Zomorodi
- Department of Anesthesia, Stanford University, California, USA
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Carlile DJ, Zomorodi K, Houston JB. Scaling factors to relate drug metabolic clearance in hepatic microsomes, isolated hepatocytes, and the intact liver: studies with induced livers involving diazepam. Drug Metab Dispos 1997; 25:903-11. [PMID: 9280396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Microsomal protein recovery and hepatocellularity have been determined and investigated as scaling factors for interrelating clearance by hepatic microsomes, freshly isolated hepatocytes and whole liver from untreated (UT) rats and rats treated with either the cytochrome P450 inducer phenobarbital (PB) or dexamethasone (DEX). Hepatocellularity in UT rats (1.1 x 10(8) hepatocytes/g liver) was not significantly different after either PB or DEX induction (1.1 and 1.3 x 10(8) hepatocytes/g liver, respectively). However the microsomal protein recovery index, which provides a scaling factor that is inversely related to the efficiency of the microsomal preparation procedure, was 47 mg/g liver in both PB and DEX microsomes and differs from UT rats (60 mg/g liver). These contrasting findings are consistent with the interlaboratory trends in the literature, indicating that, although hepatocellularity estimates are in good accord, microsomal recovery can vary 2-fold; this has implications for scaling. The oxidation of diazepam to its three primary metabolites was measured in PB and DEX microsomes and hepatocytes and the scaling factors were applied to these data and previously reported UT data. Marked changes in kinetics occur on induction resulting in a shift in the major pathway. In particular, 3-hydroxylation is induced over 20-fold by DEX. Diazepam CL(int) was determined in vivo after administration of a bolus dose into the hepatic portal vein of UT, PB, and DEX rats; values of 127, 191, and 323 ml/min/SRW (where SRW is a standard rat weight of 250 g), respectively, were obtained. Using these scaling factors, the hepatocyte predictions of CL(int) were excellent (99, 144, and 297 ml/min/SRW for UT, PB, and DEX, respectively), whereas only the DEX prediction (248 ml/min/SRW) was accurate for the microsomal system, with a substantial underprediction for UT and PB (46 and 68 ml/min/SRW, respectively). Evidence is presented for product inhibition, resulting from accumulation of primary metabolites within the microsomal preparation, as the mechanism responsible for this underprediction. These results illustrate that the scaling factor approach is applicable to induced livers in which both cytochrome P450 complement and zonal distribution are altered. These data, together with our previous studies, demonstrate that CL(int) in cells (2.4-297 ml/min/SRW), microsomes (2.7-248 ml/min/SRW), and in vivo (1.5-323 ml/min/SRW) are related in a linear fashion and hence inherently both in vitro systems are of equal value in predicting in vivo CL(int).
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Affiliation(s)
- D J Carlile
- School of Pharmacy and Pharmaceutical Sciences, University of Manchester, UK
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Abstract
1. The potency and selectivity of omeprazole as an inhibitor of cytochrome P450-mediated drug oxidations has been assessed in hepatic microsomes from the untreated, phenobarbitone-treated, beta-naphthoflavone-treated and dexamethasone-treated rat. Using the marker substrates diazepam, ethoxycoumarin, ethoxyresofurin and ethylmorphine in the above microsomal preparations, inhibitory activity against CYP1A, 2B, 2C and 3A members of the cytochrome P450 superfamily were determined. 2. In each situation studied the kinetics of inhibition by omeprazole were competitive in nature with Ki's ranging from 25 to > 1000 microM. Marker activities for the 3A family in microsomes from the dexamethasone-treated and phenobarbitone-treated rat (3-hydroxylation of diazepam and N-demethylation of ethylmorphine) were most susceptible to omeprazole inhibition (Km/Ki ratios greater than unity) compared with marker activities for the CYP1A, 2B and 2C sub-families (Km/Ki ratios < or = unity). 3. Omeprazole sulphoxide showed similar potency and selectivity of inhibition to its parent drug. Analogous studies with the same marker activities using ketoconazole indicated that both omeprazole and its sulphoxide metabolite are less potent as an inhibitor of cytochrome P4503A in rat than this well characterised prototype.
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Affiliation(s)
- K Zomorodi
- Department of Pharmacy, University of Manchester, UK
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Abstract
1. The metabolism of diazepam to its primary metabolites 3-hydroxydiazepam (3HDZ) and nordiazepam (NDZ) was evaluated in human liver microsomes. The 3HDZ pathway was the major route of metabolism representing 90% of total metabolism with a Vmax/Km ratio of 0.50-7.26 microliters min-1 mg-1 protein. 2. Inhibition of the two metabolic pathways of diazepam by omeprazole was investigated. The NDZ pathway was not affected by omeprazole whilst a Ki of 201 +/- 89 microM was obtained for the 3HDZ pathway (Km/Ki ratio of 3.0 +/- 0.9). 3. Inhibitory effects of omeprazole sulphone on the 3HDZ and NDZ pathways were also investigated. Omeprazole sulphone inhibited both pathways with similar Kis of 121 +/- 45 and 188 +/- 73 microM respectively (Km/Ki ratios of 5.2 +/- 2.3 and 3.3 +/- 1.5 respectively). 4. These in vitro data provide direct evidence for cytochrome P450 inhibition as the mechanism for the well documented diazepam-omeprazole clinical interaction and indicate that omeprazole sulphone, as well as the parent drug, contribute to the inhibition effect.
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Affiliation(s)
- K Zomorodi
- Department of Pharmacy, University of Manchester, UK
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Abstract
PURPOSE The inhibitory effects of omeprazole on diazepam metabolism in vitro and in vivo are compared in the rat. METHODS 3-hydroxylation and N-demethylation of diazepam was investigated in the presence of a range of omeprazole concentrations (2-500 microM) in hepatic microsomes and hepatocytes. Zero order infusions together with matched bolus doses of omeprazole were used to achieve a range of steady state plasma concentrations (10-50mg/L) and to study the diazepam-omeprazole interaction in vivo. RESULTS The 3-hydroxlation pathway was more prone to inhibition (KIs 108 +/- 30 and 28 +/- 11 microM in microsomes and hepatocytes, respectively) than the demethylation pathway (KIs of 226 +/- 76 and 59 +/- 27 microM in microsomes and hepatocytes, respectively). In both in vitro systems, the mechanism of inhibition was competitive with Km/KI ratios larger than 1 for the 3HDZ pathway and smaller than 1 for the NDZ pathway. There was an omeprazole concentration dependent decrease in diazepam clearance in vivo which could be modelled using a simple inhibition equation with a KI of 57 microM (19.8mg/L). In contrast there was no statistically significant change in the steady state volume of distribution for diazepam in the presence of omeprazole. CONCLUSIONS The in vivo KI for the omeprazole: diazepam inhibition interaction shows closer agreement with the KI values obtained in hepatocytes than with those observed in microsomes.
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Affiliation(s)
- K Zomorodi
- Department of Pharmacy, University of Manchester, UK
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Zomorodi K, Carlile DJ, Houston JB. Kinetics of diazepam metabolism in rat hepatic microsomes and hepatocytes and their use in predicting in vivo hepatic clearance. Xenobiotica 1995; 25:907-16. [PMID: 8553684 DOI: 10.3109/00498259509046662] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
1. The rates of diazepam (DZ) metabolism to the primary metabolites 3-hydroxydiazepam, 4'-hydroxydiazepam and nordiazepam were studied in vitro using rat hepatic microsomes and hepatocytes. 4'-hydroxydiazepam had the largest intrinsic clearance (Vmax/Km ratio, CL(int)) in both microsomes and hepatocytes representing 49 and 70% of total metabolism respectively. Whereas the contribution of 3-hydroxydiazepam was similar in both systems (21-24%), the N-demethylation pathway was greater in microsomes (27%) than hepatocytes (9%). 2. The pharmacokinetics of DZ were determined in vivo using the intraportal route to avoid blood flow limitations due to the high clearance of DZ. No dose dependency was observed in either clearance or steady state volume of distribution, which were estimated to be 38 ml/min/SRW (where SRW is a standard rat weight of 250 g) and 1.3 L/SRW respectively. Blood binding of DZ was concentration independent, the unbound fraction being 0.22. 3. Scaling factors were used to relate the in vitro CL(int) to the in vivo unbound clearance. Hepatocytes (123 ml/min/SRW) produced a more realistic prediction for the in vivo value (174 ml/min/SRW) than microsomes (41 ml/min/SRW). This situation is believed to arise from the quantitative differences in the three metabolic pathways in the two in vitro systems. It is speculated that end product inhibition is responsible for reduced total metabolism in microsomes whereas hepatocytes operate kinetically in a manner close to in vivo.
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Affiliation(s)
- K Zomorodi
- Department of Pharmacy, University of Manchester, UK
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Matthew D, Brennan B, Zomorodi K, Houston JB. Disposition of azole antifungal agents. I. Nonlinearities in ketoconazole clearance and binding in rat liver. Pharm Res 1993; 10:418-22. [PMID: 8464816 DOI: 10.1023/a:1018996524141] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The disposition of ketoconazole was characterized in the rat over a wide dose/concentration range. Bolus dose (0.03-10 mg/kg) studies indicate that plasma concentration-time profiles for ketoconazole are not superimposable when dose normalized because of nonlinearities occurring in both volume of distribution and clearance. The volume of distribution decreases from 3 to less than 1 L/kg, while the plasma clearance decreases 10-fold from 25 mL/min/kg as the dose is escalated. From these results, infusion rates were calculated to maintain the plasma concentrations achieved with particular bolus doses. The curvilinear relationship between steady-state plasma concentration (0.015-8.3 mg/L) and ketoconazole infusion rate (0.021-2.45 mg/hr/kg) was analyzed in terms of Michaelis-Menten kinetics. A Vmax of 3.2 mg/hr/kg and Km of 2.1 mg/L were obtained by nonlinear regression analysis. At the end of the ketoconazole infusion, liver, adrenals and kidneys were removed and assayed for ketoconazole. Tissue-to-plasma partition coefficients for the liver and adrenals showed a marked dependence upon steady-state plasma concentration. Both parameters (liver, 22; and adrenals, 53) showed a decrease of approximately 10-fold as the plasma concentrations were increased. In contrast, the kidney:plasma partition coefficient (1.8), blood:plasma concentration ratio (0.6), and plasma binding (96%) of ketoconazole did not show a concentration dependence over the range studied. It is concluded that the liver is an important determinant of ketoconazole's volume of distribution and that saturation of this process accounts largely for the reduction in volume of distribution with increasing dose.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- D Matthew
- Department of Pharmacy, University of Manchester, UK
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