Question

an antimicrobial drug that is produced in the laboratory entirely by chemical reactions is called a(n)
drug.

Explanation:

In the field of Medicine and Health (a subfield of Natural Science), an antimicrobial drug made entirely via chemical reactions in a lab is defined as a synthetic antimicrobial drug. Synthetic drugs are created through chemical synthesis rather than being derived from natural sources (like antibiotics from microbes).

Answer:

synthetic