This variation is enough to provoke undesired side effects like acute kidney injury and hepatotoxicity with a seemingly regular dose [10-11]. It also raises concern regarding drug interactions, in particular those that cause inhibition of cytochrome P450 3A4, potentiating the side effects of monacolin [4, 7]. In this case, fortunately, our patient’s medication did not significantly interact with monacolin. The gene discussed is CYP3A4; the disease is acute kidney injury.