Rhode Island Multistate Pharmacy Jurisprudence (MPJE) Practice Exam

Which of the following describes a risk associated with medications that have a narrow therapeutic window?

1. Lower efficacy in treatment

2. Higher potential for toxicity

3. Increased drug interactions

4. Longer duration of action

The correct answer is: Higher potential for toxicity

Medications with a narrow therapeutic window are those where the difference between the therapeutic dose and the toxic dose is very small. This characteristic means that even slight changes in dosage, plasma concentration, or patient response can lead to adverse effects. Therefore, the higher potential for toxicity is a significant risk, as patients must be monitored closely to ensure they remain within the safe and effective range of the medication. While considerations such as drug interactions or duration of action are important aspects of pharmacotherapy, they do not specifically pertain to the inherent risk posed by the narrow therapeutic window itself. The focus here is on how closely dosing must be managed to avoid toxicity, which directly relates to the nature of the drug’s therapeutic index.