Sex-specific differences in CYP450 isoforms in humans

Background: The activity of various CYP isoforms is critical for maintaining the clinical effectiveness of many medications. Therefore, determining the sex-dependent activity of clinically relevant CYP families is highly important for optimal therapeutic effectiveness. Objective: This review examined the sex-dependent activity of CYP3A, CYP1A2, CYP2136, CYP2C9, CYP2C19 and CYP2E1. Methods: This review searched for studies performed in humans and hormonal status was not a limiting factor. Results/conclusions: The current evidence suggests that CYP2E1 and CYP1A2 activity is higher in males than females, while CYP3A, one of the most clinically relevant CYP isoforms, appears to have greater activity in females. Overall, more studies are needed to fully support these conclusions as there are many factors that influence drug metabolism and thus it is very difficult to isolate gender as a sole modulator of CYP activity.