Acta Scientific Pharmacology

Research Article Volume 2 Issue 10

Pharmacogenetic Analysis of Three Cytochrome P450 Gene Polymorphisms (CYP2D6, CYP3A4, and CYP3A5) in Methadone Maintenance Patients

Evan Minami1*, Kory Johnson2, Kaylene Au3, Douglas Johnson3,4,5, Lisa Cook5, Steven Namiki3, Richard Severino4 and Christopher Lum3,4

1University of Southern California, Los Angeles, CA, USA

2New York University, New York, NY, USA

3John A. Burns School of Medicine, Honolulu, HI, USA

4The Queen's Medical Center, Honolulu, HI, USA

5Kū Aloha Ola Mau, Honolulu, HI, USA

*Corresponding Author: Evan Minami, University of Southern California, Los Angeles, CA, USA.

Received: August 21, 2021; Published: September 30, 2021


Best practice guidelines and the Substance Abuse and Mental Health Services Administration (SAMHSA) Treatment Improvement Protocol 63 mandates methadone maintenance induction with low initial dosage and a small, slow increase to avoid overdose and to reach a steady state. Primarily metabolized by the cytochrome 2D6 enzyme, it is shown that polymorphisms in this subunit can greatly affect the rate at which methadone is metabolized in individuals. Six genetic polymorphisms are commonly identified which ranged from poor metabolizers to ultrarapid metabolizers. Patients who can’t reach a steady state dose in a reasonable time because of slow incremental dose increases can be more susceptible to relapse and slow metabolizers can be susceptible to overdose. Phenotypic data of CYP2D6 polymorphisms can guide better initial dosing for patients that may require a higher dose to reach a steady state. To date, there has been no way to predict the dose needed for a steady state. A total of 25 patients were enrolled and genotyped with an average time on methadone of 14.2 years and ages 31 to 75 years. Ultra-rapid metabolizers were shown to require significantly higher doses of methadone to reach a steady state. This was a pilot study that supports further research into methadone pharmacogenomics.


Keywords: Methadone; Pharmacogenomics; CYP2D6


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Citation: Evan Minami., et al. “Pharmacogenetic Analysis of Three Cytochrome P450 Gene Polymorphisms (CYP2D6, CYP3A4, and CYP3A5) in Methadone Maintenance Patients". Acta Scientific Pharmacology 2.10 (2020): 02-07.


Copyright: © 2021 Evan Minami., et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


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