What is a primary purpose of Phase IV studies?

• A. Optimize the drug's use
• B. Determine initial safety in humans
• C. Establish dosage in healthy volunteers
• D. Develop the chemical synthesis

Answer: (A)

Phase IV studies come after a drug is approved and on the market, with the goal of optimizing how the drug is used in real-world practice. They collect long-term safety and effectiveness data from a broader, more diverse patient population, detect rare or delayed adverse effects, and help refine dosing recommendations and labeling. This post-marketing surveillance supports better risk management and ensures the drug’s use remains appropriate as experience with it grows. The other options describe activities that happen earlier in development—Phase I assesses initial safety in humans and healthy volunteer dosing, while chemical synthesis development occurs outside of these clinical phases.