Final answer:
Drug sensitivity refers to when an individual has an allergic reaction to a drug, distinct from antibiotic resistance which is caused by bacteria evolving to survive drug treatments.
Step-by-step explanation:
Drug sensitivity occurs when an individual develops an allergic reaction to a drug he or she is taking. This can be an immune response to the drug itself or to one of its metabolites. It is important to differentiate this from antibiotic resistance, which is when bacteria change in a way that reduces the effectiveness of drugs, chemicals, or other agents designed to cure or prevent infections. This antibiotic resistance is a significant global health threat as it makes treating infections much more difficult, leading to worse clinical outcomes and higher healthcare costs. Resistance can emerge when antibiotics are overprescribed, or when patients do not complete their prescribed course of antibiotics. Understanding the difference between drug interactions is also crucial; for example, synergistic interactions improve treatment efficacy, while antagonistic interactions may reduce drug activity or increase potential for toxicity.