SLCO1B1 haplotypes affect atorvastatin pharmacokinetics in 82 healthy volunteers. (a) SLCO1B1 haplotypes calculated on the presence of the four previously described key variants and change in atorvastatin area under the plasma concentration-time curve (AUC), corrected for body weight, in comparison with the reference haplotype SLCO1B1*1a. Haplotypes are given with a frequency > 2%. (b) SLCO1B1 genotypes (percentage genotype frequencies in brackets) are sorted by median atorvastatin AUC. SLCO1B1 alleles harboring only variant c.388A > G and not c.521T > C (boldface) confer considerably lower AUCs with lowest levels in homozygous variant or compound heterozygous carriers for the SLCO1B1*14 or *1b alleles. Horizontal line indicates the median; boxes indicate 25th to 75th percentiles; whiskers indicate non-outlier range.