Which of the following can change the effectiveness of medication?

Drug interactions are critical factors that can significantly change the effectiveness of medication. When one drug interacts with another, it may cause an increase or decrease in the effectiveness of either drug, lead to unexpected side effects, or even create dangerous health situations. This can occur due to various mechanisms, such as altered metabolism, competition for binding sites, or changes in absorption rates. Understanding these interactions is crucial for healthcare providers and patients to ensure safe and effective medication use.

Other options, while they contribute to overall health and well-being, do not inherently change medication effectiveness in the same direct way that drug interactions do. For instance, a healthy diet, regular exercise, and adequate hydration are all vital for maintaining general health and supporting medication absorption and metabolic processes, but these factors do not involve the direct pharmacological changes that occur with drug interactions. Therefore, while important, they do not compare to the impact that drug interactions have on medication effectiveness.