OUD	Opioid use disorder
CBT	Cognitive Behavioral Therapy
CM	Contingency Management
MOR	µ-opioid receptor
NMDA	N-methyl-D-aspartate
CYP450	Cytochrome P450
EDDP	2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine
EMDP	2-ethyl-5-methyl-3,3-diphenyl-1-pyrroline
SNP	Single Nucleotide Polymorphism
GWAS	Genome-Wide Association Study
MMT	Methadone Maintenance Treatment
PRISMA	Preferred Reporting Items for Systematic Reviews and Meta-Analyses
NHLBI	National Heart, Lung, and Blood Institute
QTc	QT interval of the cardiac cycle
SD	Standard deviation
UMs	Ultrarapid metabolizers
RMs	Rapid metabolizers
PMs	Poor metabolizers
IMs	Intermediate metabolizers
NMs	Normal metabolizers
ABC	ATP-binding cassette
CPIC®	Clinical Pharmacogenetics Implementation Consortium
PharmGKB	Pharmacogenomics Knowledge Base
POR	Cytochrome P450 oxidoreductase
NADPH	Nicotinamide adenine dinucleotide phosphate oxidase
PXR	Pregnane X receptor
MetS	Metabolic syndrome
AEMPS	Spanish Agency of Drugs and Medical Products