Several factors can influence the activity of CYP450 enzymes. Genetic polymorphisms can lead to variations in enzyme activity, which can affect an individual's response to drugs and susceptibility to toxicity. Environmental factors such as diet, smoking, and exposure to chemicals can also modulate CYP450 activity. Additionally, certain drugs can act as CYP450 inhibitors or inducers, further complicating the metabolism of co-administered drugs.
