The overall objective of this renewal application is to sustain and expand the PI's patient-oriented research program in the pharmacology of opioids and HIV/AIDS drugs, specifically directed towards the therapy of substance abuse and pain. A principal component of this program will be the development of beginning clinical investigators. The specific research objectives are to 1) continue existing research which investigates mechanisms of variability in human opioid disposition, pharmacodynamics and clinical efficacy, and endeavors to optimize opioid therapy of substance abuse and cancer pain, 2) expand existing research on the mechanism of drug interactions with HIV/AIDS drugs and their clinical consequence, 3) facilitate program expansion into underutilized therapies such as nonsteroidal antiinflammatory drugs, and 4) mentor beginning clinical investigators in patient-oriented research, utilizing the above framework to spawn independent research programs. A critical focus will be interfacing in vitro and in vivo aspects of human drug disposition and efficacy, and translating recent discoveries in basic enzymology and pharmacogenetics of drug disposition into clinical strategies for optimized therapy. Methadone maintenance is the cornerstone of opiate abuse therapy, a vital and effective strategy for HTV/AIDS risk reduction, and widely used for cancer pain treatment. Methadone is characterized by extreme, unexplained, and unpredictable interindividual pharmacokinetic variability, causing inadequate pain treatment, opioid abstinence syndrome, treatment failures, and unwanted side effects. Methadone is metabolized by hepatic and intestinal cytochrome P450, and is a substrate for transporters in the intestine, brain, and kidney. Mechanism(s) of individual variability in methadone metabolism and transport are, however, unknown, as are their clinical consequences. Highly active antiretroviral therapy (HAART) is the cornerstone HIV/AIDS treatment, yet HIV/AIDS drugs cause profound, complex, and poorly understood drug interactions. To address these questions, experiments in vitro will use human liver and intestinal microsomes and transfected cell lines to identify relevant P450 isoforms and transporters and probe drug-drug interactions. Complementary clinical investigations will verify these identifications and establish the mechanism of HTV/AIDS drug interactions, and the influence of drug interactions and pharmacogenetics on opioid disposition and pharmacologic effects. Successful identification of the factors affecting metabolism, clearance, and clinical effects of methadone will improve the clinical outcome and reduce the costs of opiate addiction and cancer pain treatment. Successful identification of the mechanism of HIV/AIDS drug interactions will improve the therapy of HIV/AIDS.

Agency
National Institute of Health (NIH)
Institute
National Institute on Drug Abuse (NIDA)
Type
Midcareer Investigator Award in Patient-Oriented Research (K24)
Project #
5K24DA000417-08
Application #
7065214
Study Section
Human Development Research Subcommittee (NIDA)
Program Officer
Patel, Amrat
Project Start
1999-05-01
Project End
2010-03-31
Budget Start
2006-04-01
Budget End
2007-03-31
Support Year
8
Fiscal Year
2006
Total Cost
$164,419
Indirect Cost
Name
Washington University
Department
Anesthesiology
Type
Schools of Medicine
DUNS #
068552207
City
Saint Louis
State
MO
Country
United States
Zip Code
63130
Kharasch, Evan D (2017) Current Concepts in Methadone Metabolism and Transport. Clin Pharmacol Drug Dev 6:125-134
Horst, Jennifer; Frei-Jones, Melissa; Deych, Elena et al. (2016) Pharmacokinetics and analgesic effects of methadone in children and adults with sickle cell disease. Pediatr Blood Cancer 63:2123-2130
Duma, Andreas; Cartmill, Christopher; Blood, Jane et al. (2015) The hematological effects of nitrous oxide anesthesia in pediatric patients. Anesth Analg 120:1325-30
Kharasch, Evan D; Regina, Karen J; Blood, Jane et al. (2015) Methadone Pharmacogenetics: CYP2B6 Polymorphisms Determine Plasma Concentrations, Clearance, and Metabolism. Anesthesiology 123:1142-53
Gadel, Sarah; Friedel, Christina; Kharasch, Evan D (2015) Differences in Methadone Metabolism by CYP2B6 Variants. Drug Metab Dispos 43:994-1001
Brier, Matthew R; Wu, Qian; Tanenbaum, Aaron B et al. (2015) Effect of HAART on Brain Organization and Function in HIV-Negative Subjects. J Neuroimmune Pharmacol 10:517-21
Meissner, Konrad; Blood, Jane; Francis, Amber M et al. (2014) Cyclosporine-inhibitable cerebral drug transport does not influence clinical methadone pharmacodynamics. Anesthesiology 121:1281-91
Campbell, Scott D; Regina, Karen J; Kharasch, Evan D (2014) Significance of lipid composition in a blood-brain barrier-mimetic PAMPA assay. J Biomol Screen 19:437-44
Sai, Kiran Kumar Solingapuram; Fan, Jinda; Tu, Zhude et al. (2014) Automated radiochemical synthesis and biodistribution of [¹¹C]l-?-acetylmethadol ([¹¹C]LAAM). Appl Radiat Isot 91:135-40
Kaspera, Rüdiger; Kirby, Brian J; Sahele, Tariku et al. (2014) Investigating the contribution of CYP2J2 to ritonavir metabolism in vitro and in vivo. Biochem Pharmacol 91:109-18

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