Which factor does NOT influence a patient's response to medication?

The correct response identifies social media usage as a factor that does not influence a patient's response to medication. When considering how patients respond to medications, there are several critical elements to take into account:

Pharmacokinetics refers to how the body absorbs, distributes, metabolizes, and excretes a medication. Each person's unique pharmacokinetic profile can significantly affect how they respond to a drug, including its effectiveness and the presence of side effects.

Pharmacogenomics involves the study of how a person's genetic makeup affects their response to medications. Variations in genes can lead to differences in drug metabolism and efficacy, making this a crucial factor in determining the appropriateness of certain medications for individual patients.

Environmental influences encompass various factors such as living conditions, exposure to pollutants, or social support systems that can impact both the efficacy of medications and a patient’s adherence to a prescribed treatment plan.

In contrast, while social media usage may have indirect effects on mental health and overall well-being, it does not directly influence the biological mechanisms by which a medication exerts its effect on the body. Therefore, among the listed options, social media usage stands out as not having a direct impact on medication response.