Hello,
concept_id 1539407 is mapping to 45020745 as well as 45072043, but 1539407 is a statin while the other codes are antibiotics which are not HMG-CoA reductase inhibitors.
Similarly 1545997 is a statin but is also mapping with 36401583, 36401584, 36401585 which is Alprazolam (Xanax) which is not a statin.