A Nurse Is Reviewing Drug Safety with a Student Nurse

A nurse is reviewing drug safety with a student nurse. The nurse explains that the median lethal dose of drugs is often determined in laboratory preclinical trials because of which factors? Note: Credit will be given only if all correct choices and no incorrect choices are selected. Select all that apply.

A) It would be unethical to determine these values in human subjects.
B) The safety of the medication must be determined prior to clinical trials.
C) It is difficult to obtain sufficient participants for clinical trials.
D) Clinical trials determine only the effective dose of a drug.
E) It is too costly to conduct the studies during clinical trials.