Multivariate regression analysis allowed attribution of 31.8 % of QTc variability to methadone dose , cytochrome P-450 3A4 drug-drug interactions , hypokalemia , and altered liver function .
O O O O O O O O O O O O B-ChemicalEntity O O B-GeneOrGeneProduct I-GeneOrGeneProduct I-GeneOrGeneProduct O O O B-DiseaseOrPhenotypicFeature O O O O O O