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Gomeni R, Bressolle-Gomeni F, Spencer TJ, Faraone SV, Fang L, Babiskin A. Model-Based Approach for Optimizing Study Design and Clinical Drug Performances of Extended-Release Formulations of Methylphenidate for the Treatment of ADHD. Clin Pharmacol Ther 2017; 102:951-960. [PMID: 28369788 DOI: 10.1002/cpt.684] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 02/13/2017] [Accepted: 03/05/2017] [Indexed: 12/12/2022]
Abstract
Methylphenidate (MPH) is currently used to treat children with attention deficit hyperactivity disorder (ADHD). Several extended-release (ER) formulations characterized by a dual release process were developed to improve efficacy over an extended duration. In this study, a model-based approach using literature data was developed to: 1) evaluate the most efficient pharmacokinetic (PK) model to characterize the complex PK profile of MPH ER formulations; 2) provide PK endpoint metrics for comparing ER formulations; 3) define criteria for optimizing development of ER formulations using a convolution-based model linking in vitro release, in vivo release, and hour-by-hour behavioral ratings of ADHD symptoms; and 4) define an optimized trial design for assessing the activity of MPH in pediatric populations. The convolution-based model accurately described the complex PK profiles of a variety of ER MPH products, providing a natural framework for establishing an in vitro/in vivo correlation and for defining criteria for assessing comparative bioequivalence of MPH ER products.
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Affiliation(s)
- R Gomeni
- Pharmacometrica, La Fouillade, France
| | | | - T J Spencer
- Massachusetts General Hospital, Boston, Massachusetts, USA
| | - S V Faraone
- SUNY Upstate Medical University, Syracuse, New York, USA
| | - L Fang
- Division of Quantitative Methods and Modeling, Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - A Babiskin
- Division of Quantitative Methods and Modeling, Office of Research and Standards, Office of Generic Drugs, Center for Drug Evaluation and Research, US Food and Drug Administration, Silver Spring, Maryland, USA
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Enioutina EY, Constance JE, Stockmann C, Linakis MW, Yu T, Rower JE, Balch AH, Sherwin CM. Pharmacokinetic considerations in the use of antivirals in neonates. Expert Opin Drug Metab Toxicol 2015; 11:1861-78. [PMID: 26535960 DOI: 10.1517/17425255.2015.1108963] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION Neonatal patients, because of the inability of their immune system to properly respond to microbial challenge, are highly susceptible to viral infections. Immunoglobulins, monoclonal antibody and antiviral drugs are used for prophylaxis and treatment of viral diseases in neonates. Neonates and, especially, preterm infants differ in drug absorption, distribution, metabolism and excretion from adults and older children. AREAS COVERED This review will evaluate deficiencies of neonatal immune responses to microbial challenge that predispose newborns to viral infections, clinical manifestations and the treatment of viral diseases in neonates. We focus on published studies describing antiviral drug pharmacokinetics in neonates and make recommendations on the dosing of these drugs, allowing achievement of maximal clinical benefits in neonates. EXPERT OPINION While some efforts were undertaken to study pharmacokinetics and pharmacodynamics of antiviral drugs, much more needs to be done. Current data indicate that the pharmacokinetics of antiviral drugs may vary significantly depending on gestational age, maturation processes of drug-metabolizing enzymes and renal clearance. Specifics of pharmacokinetics of antiviral drugs need to be taken into consideration when they are prescribed to neonates and infants.
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Affiliation(s)
- Elena Yu Enioutina
- a Division of Clinical Pharmacology, Department of Pediatrics , University of Utah School of Medicine , 295 Chipeta Way, Salt Lake City , UT 84108 , USA.,b Division of Microbiology and Immunology, Department of Pathology , University of Utah School of Medicine , 15 North Medical Drive East, Salt Lake City , UT 84112 , USA
| | - Jonathan E Constance
- a Division of Clinical Pharmacology, Department of Pediatrics , University of Utah School of Medicine , 295 Chipeta Way, Salt Lake City , UT 84108 , USA
| | - Chris Stockmann
- a Division of Clinical Pharmacology, Department of Pediatrics , University of Utah School of Medicine , 295 Chipeta Way, Salt Lake City , UT 84108 , USA
| | - Matthew W Linakis
- a Division of Clinical Pharmacology, Department of Pediatrics , University of Utah School of Medicine , 295 Chipeta Way, Salt Lake City , UT 84108 , USA
| | - Tian Yu
- a Division of Clinical Pharmacology, Department of Pediatrics , University of Utah School of Medicine , 295 Chipeta Way, Salt Lake City , UT 84108 , USA
| | - Joseph E Rower
- a Division of Clinical Pharmacology, Department of Pediatrics , University of Utah School of Medicine , 295 Chipeta Way, Salt Lake City , UT 84108 , USA
| | - Alfred H Balch
- a Division of Clinical Pharmacology, Department of Pediatrics , University of Utah School of Medicine , 295 Chipeta Way, Salt Lake City , UT 84108 , USA
| | - Catherine M Sherwin
- a Division of Clinical Pharmacology, Department of Pediatrics , University of Utah School of Medicine , 295 Chipeta Way, Salt Lake City , UT 84108 , USA
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Abstract
BACKGROUND There are no previous data describing nelfinavir and lamivudine pharmacokinetics in neonates treated with weight-band dosing regimens. DESIGN Pharmacokinetic study of nelfinavir and lamivudine pharmacokinetics in infants during the first 2 weeks of life treated with weight-band dosing regimens. METHODS Intensive 12-hour pharmacokinetic profiles were performed between either days 4-7 or days 10-14 of life in 26 Brazilian infants. RESULTS Pharmacokinetic data were obtained from 26 infants who received median (range) per kg doses of 58.8 (48.4-79.0) mg/kg for nelfinavir and 2.0 (1.5-3.2) mg/kg for lamivudine. Median nelfinavir 12-hour AUC (AUC0-12) was 25.5 (1.7-183.5) μg*h/mL and median 12-hour concentration (C12h) was 1.09 (<0.04-14.44) μg/mL. AUC0-12 was less than 15 μg*h/mL (the 10% for adults) in 12 infants (46%). Median lamivudine AUC0-12 was 7.8 (2.7-15.6) μg*h/mL and median C12h was 0.23 (<0.04-0.74) μg/mL. CONCLUSIONS : Lamivudine pharmacokinetic parameters observed in this study were consistent with those seen in other studies of neonates. While median nelfinavir AUC and C12h in these neonates were above the exposure targets, interindividual variability in nelfinavir exposure was large and nelfinavir exposure failed to meet the exposure targets in 46% of infants.
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Hirt D, Urien S, Jullien V, Firtion G, Rey E, Pons G, Blanche S, Treluyer JM. Age-related effects on nelfinavir and M8 pharmacokinetics: a population study with 182 children. Antimicrob Agents Chemother 2006; 50:910-6. [PMID: 16495250 PMCID: PMC1426418 DOI: 10.1128/aac.50.3.910-916.2006] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
As a relationship between nelfinavir antiretroviral efficacy and plasma concentrations has been previously established, nelfinavir pharmacokinetics was investigated in order to optimize the individual treatment schedule in a pediatric population. A population pharmacokinetic model was developed to describe the concentration-time course of nelfinavir and its active metabolite M8. Individual characteristics were used to explain the large interindividual variability in children. Data from therapeutic drug monitoring in 182 children treated with nelfinavir were analyzed with NONMEM. Then Food and Drug Administration (FDA) current recommendations were evaluated estimating the percentage of children who reached the target minimum plasma concentration (0.8 mg/liter) by using Bayesian estimates. Nelfinavir pharmacokinetics was described by a one- compartment model with linear absorption and elimination. Pharmacokinetic estimates and the corresponding intersubject variabilities for the model were as follows: nelfinavir total clearance, 0.93 liters/h/kg (39%); volume of distribution, 6.9 liters/kg (109%); absorption rate, 0.5 h(-1); formation clearance fraction to hydroxy-tert-butylamide (M8), 0.025; M8 elimination rate, 1.88 h(-1) (49%). Apparent nelfinavir total clearance and volume of distribution decreased as a function of age. M8 elimination rate was increased by concomitant administration of nevirapine or efavirenz. Our data confirm that the FDA recommendations for children from 2 to 13 years are optimal and that the dose recommended for children younger than 2 years is adequate for the children from 2 months to 2 years old. However, in children younger than 2 months, the proposed nelfinavir newborn dose of 40 mg/kg of body weight twice daily is inadequate and we suggest increasing the dose to 50 to 60 mg/kg administered thrice daily. This assumption should be further evaluated.
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Affiliation(s)
- Déborah Hirt
- Pharmacologie Clinique, Assistance Publique--Hôpitaux Paris, France.
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Olmo M, Podzamczer D. A review of nelfinavir for the treatment of HIV infection. Expert Opin Drug Metab Toxicol 2006; 2:285-300. [PMID: 16866614 DOI: 10.1517/17425255.2.2.285] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Nelfinavir (NFV) is a protease inhibitor that has been widely used for several years for the treatment of HIV infection. This has led to extensive experience with NFV-containing regimens, in which the drug has shown prolonged viral suppression, good tolerability and a unique resistance profile. In recent years, several antiretroviral drugs with some advantages over NFV have been developed. Nevertheless, NFV has favourable characteristics that make it a suitable antiretroviral compound for many HIV-infected patients. It can be used in patients who do not tolerate ritonavir even at low doses, and it is well tolerated in pregnant women, has a low-grade interaction with methadone and may be well tolerated in hepatitis C virus-co-infected patients. In addition, its new simplified posology may contribute to improved adherence.
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Affiliation(s)
- Montserrat Olmo
- Hospital Universitario de Bellvitge, Infectious Diseases Service, HIV Unit, Hospitalet de Llobregat, Barcelona, Spain.
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