Pharmacy PEBC Practice Exam

What factors can influence drug efficacy?

1. Doctor's prescriptions

2. Patient adherence to dosage

3. Patient age, weight, and genetic factors

4. Time since medication release

The correct answer is: Patient age, weight, and genetic factors

The factors that influence drug efficacy are multifaceted, and one of the most significant is patient-specific characteristics such as age, weight, and genetic factors. Age can affect how drugs are metabolized and eliminated from the body. For instance, children and the elderly may respond differently to medications compared to young adults due to differences in metabolic rates and organ function. Weight is also crucial because it can determine the volume of distribution of the drug in the body. Medications may require dosage adjustments based on body weight, particularly in drugs that have a narrow therapeutic index. Genetic factors, often referred to as pharmacogenomics, can significantly impact drug response by influencing metabolic pathways. For example, certain individuals might have genetic variations that affect enzymes involved in drug metabolism, leading to either increased toxicity or reduced efficacy. While prescriptions by healthcare providers and patient adherence to dosage are important for therapeutic outcomes, they are not inherent characteristics of the drug or the patient's body and thus do not directly influence the biological efficacy of the drug itself. The time since medication release might affect factors such as the drug's market availability or knowledge of side effects but does not inherently change how effective a drug is within individual patients. In summary, patient age, weight, and genetic factors are critical