Final answer:
The variables that affect drug processing in the body are age, weight, sex, and psychological state; these factors influence drug pharmacokinetics and personalized medicine approaches.
Step-by-step explanation:
The variables affecting the speed and efficiency of drugs being processed by the body are age, weight, sex, and psychological state. These factors contribute to individual differences in drug pharmacokinetics, which is the study of how an organism affects a drug. Age can influence the metabolic rate and the body's response to drugs. Weight can impact the distribution and elimination of a drug, while sex can affect how drugs are absorbed, distributed, metabolized, and excreted. Genetic characteristics are also important as they can result in genetic polymorphisms that affect drug metabolism enzymes. Lastly, a person’s psychological state can influence medication adherence and physiological responses to drugs. Understanding these variables is crucial for individualizing drug therapy, maximizing drug efficacy, and minimizing side effects, a practice often referred to as personalized medicine.