Which two factors influence drug dosage and action?

The factors that significantly influence drug dosage and action include the resident (patient) and the drug type. The term "resident" refers to the individual receiving the medication, whose unique characteristics, such as age, weight, health status, and specific medical conditions, can affect how their body responds to different drugs. For example, an elderly patient may metabolize a medication differently compared to a younger adult, impacting the efficacy and safety of the drug.

The type of drug itself is crucial because different medications have varying mechanisms of action, half-lives, and side effects. For instance, medications in the same class may require different dosages depending on how potent they are or how the body processes them. Understanding both the resident's characteristics and the specific drug type is essential for determining the appropriate dosage and predicting how the drug will perform in the individual's body.

In contrast, other options contain factors that, while relevant to medication administration, do not directly influence the core aspects of drug dosage and overall pharmacological action to the same degree.