sometimes the FDA approves a drug for general use but requires the manufacturer to continue to monitor its effects; during this phase the drug may be tried on slightly different patient populations than those studied in earlier trials
例句
例句
PhaseIV: 6 weeks after surgery.
阶段IV: 在手术后6个星期。
PhaseIV study sword skill.
第四阶段学习刀法。
This definition includes Phase I to PhaseIV trials.