Rs1128503

rs1128503 is a SNP in the transporter P-glycoprotein (P-gp) 170, encoded by the ABCB1 (also known as MDR1) gene. Methadone is a substrate of this protein, so variants may affect the efficacy and optimal dosage of this drug as used for treating opiate dependence.

A study of 98 methadone-maintaining patients concluded that the higher (>150 mg/day) and lower (< or =150 mg/day) methadone dose groups differed significantly in their rs1128503 status (experiment-wise p = 0.0325). Furthermore, individuals with the 3-locus genotype pattern (T;T)-(T;T)-(T;T) for SNPs rs1045642, rs2032582 and rs1128503, respectively, had an approximately 5-fold chance of requiring the 'higher' methadone dose, while individuals heterozygous for these three SNPs have an approximately 3-fold chance of stabilizing at the 'lower' methadone dose (point-wise p-value = 0.026).

Identifying candidate causal variants responsible for altered activity of the ABCB1 multidrug resistance gene.

ABCB1 genotypes and haplotypes in patients with dementia and age-matched non-demented control patients.

MDR1 gene variants, indoor insecticide exposure, and the risk of childhood acute lymphoblastic leukemia.

ABCB1 (MDR1) gene polymorphisms are associated with the clinical response to paroxetine in patients with major depressive disorder.

Multiplexed genotyping of ABC transporter polymorphisms with the Bioplex suspension array.

Genotyping panel for assessing response to cancer chemotherapy.

Polymorphisms affecting gene transcription and mRNA processing in pharmacogenetic candidate genes: detection through allelic expression imbalance in human target tissues.

Bidirectional translational research: Progress in understanding addictive diseases.

No association of ABCB1 polymorphisms with drug-refractory epilepsy in a north Indian population.

Opiate and cocaine addiction: from bench to clinic and back to the bench.

Genetic determinants of target and novelty-related event-related potentials in the auditory oddball response.

No significant effect of ABCB1 haplotypes on the pharmacokinetics of fluvastatin, pravastatin, lovastatin, and rosuvastatin.

Influence of ABCB1 polymorphisms and haplotypes on tacrolimus nephrotoxicity and dosage requirements in children with liver transplant.

Sequence variations of ABCB1, SLC6A2, SLC6A3, SLC6A4, CREB1, CRHR1 and NTRK2: association with major depression and antidepressant response in Mexican-Americans.

Effect of CYP3A and ABCB1 single nucleotide polymorphisms on the pharmacokinetics and pharmacodynamics of calcineurin inhibitors: Part I.

Effect of CYP3A and ABCB1 single nucleotide polymorphisms on the pharmacokinetics and pharmacodynamics of calcineurin inhibitors: Part II.

Explaining variability in ciclosporin exposure in adult kidney transplant recipients.

Pazopanib-induced hyperbilirubinemia is associated with Gilbert's syndrome UGT1A1 polymorphism.

ABCB1/MDR1 gene polymorphisms as a prognostic factor in colorectal cancer.

Cytochrome P450 genetic polymorphisms influence the serum concentration of calcineurin inhibitors in allogeneic hematopoietic SCT recipients.

Pharmacogenetics of antidepressant response.

Polymorphisms of the MDR1 and MIF genes in children with nephrotic syndrome.

Association of ABCB1, 5-HT3B receptor and CYP2D6 genetic polymorphisms with ondansetron and metoclopramide antiemetic response in Indonesian cancer patients treated with highly emetogenic chemotherapy.

Polymorphisms in genes that regulate cyclosporine metabolism affect cyclosporine blood levels and clinical outcomes in patients who receive allogeneic hematopoietic stem cell transplantation.

ABCB1 haplotype is associated with major molecular response in chronic myeloid leukemia patients treated with standard-dose of imatinib.

Influence of genomic ancestry on the distribution of SLCO1B1, SLCO1B3 and ABCB1 gene polymorphisms among Brazilians.

Association between the functional polymorphism (C3435T) of the gene encoding P-glycoprotein (ABCB1) and major depressive disorder in the Japanese population.

PharmGKB summary: phenytoin pathway.