Final answer:
The antonym for "make the medicine more potable" is "undrinkable," which implies the medicine is unsafe for consumption due to harmful contaminants.
Step-by-step explanation:
The antonym for "make the medicine more potable" is "make the medicine undrinkable." In this context, potable refers to water or in this case medicine, that is safe enough to be consumed without causing harm. Potable water, as defined, is clean and does not contain harmful levels of chemical pollutants or microorganisms. Conversely, the term undrinkable implies that the water or medicine contains contaminants that render it unsafe for consumption. The presence of substances such as morphine and opium in medicines, which were once unregulated, lead to drug addiction rather than curing illnesses, making such medicines harmful or undrinkable in a figurative sense.