Question

a drug that is isolated from natural sources and then modified in the laboratory is called a(n)
drug.

Explanation:

In the field of Medicine and Health (a subfield of Natural Science), a drug isolated from natural sources and then modified in the laboratory is known as a semisynthetic drug. This is because it starts with a natural compound and undergoes chemical modification in the lab to enhance its properties (like efficacy, stability, or reduce side - effects).

Answer:

semisynthetic