Table 2.

Pharmacogenetic Medication Trials for Opioid Abuse

Gene	Polymorphism	Treatment Medication	Drug of Abuse	Sample Size	Population	Treatment × Genotype Finding* ↑ More effective ↓ Less effective ↔ No interaction	Citation
ANKK1	rs1800497	Methadone	Heroin	95	Caucasian	↓ T allele	Lawford et al. (2000)
	rs1800497	Buprenorphine	Heroin	25	Primarily Caucasian (88%)	↔	Barrat et al. (2006)
	rs1800497	Methadone	Heroin	46	Primarily Caucasian (89%)	↔	Barrat et al. (2006)
	rs1800497	Methadone	Heroin	238	Caucasian	↔	Crettol et al. (2008)
CYP3A4	*1B	Methadone	Opioids	245	Caucasian-European	↔	Crettol et al. (2006)
CYP2B6	*4, *5, *6, *9	Methadone	Opioids	245	Caucasian-European	↔	Crettol et al. (2006)
DRD1	rs4532	Methadone	Heroin	238	Caucasian	↔	Crettol et al. (2008)
DRD2	rs6277	Methadone	Heroin	238	Caucasian	↑ CC genotype	Crettol et al. (2008)
Multiple Variants	MYOCD: rs1714984, GRM8: rs1034576, CRY1: rs1861591, GRM6: rs953741, OPRM1: rs1074287, NR4A2: rs1405735, intergenic variants: rs965972, rs1867898	Methadone	Opioids	169	Caucasian	↓CRY1 AA ↓ MYOCD A allele + GRM6 AG	Fonseca et al. (2010)
OPRD1	rs2234918	Methadone	Heroin	238	Caucasian	↔	Crettol et al. (2008)
	rs678849 rs1042114 rs10753331 rs59520 rs581111 rs2234918	Buprenorphine	Opioids	566 Caucasian 77 African-American	Caucasian- and African-American	↓ African-American rs678849 CC genotype	Crist et al. (2013 A)
	rs678849 rs1042114 rs10753331 rs59520 rs581111 rs2234918	Methadone	Opioids	566 Caucasian 77 African-American	Caucasian- and African-American	↑ African-American rs678849 CC genotype	Crist et al. (2013 A)
	rs678849 rs1042114 rs10753331 rs59520 rs581111 rs2234918	Buprenorphine Methadone	Opioids	582	European-American	↓ Female rs581111 AA/AG genotype ↓ Female rs529520 AA genotype	Clarke et al. (2014 A)
OPRM1	rs1799971	Methadone	Heroin	238	Caucasian	↔	Crettol et al. (2008)
	G-172T: rs6912029 G-1510A: rs12205732	Oral Naltrexone	Opioids	138	Arab	↓ 172GG and 1510GG	Al-Eitan et al. (2012)