Not all drugs are considered medicines because .A. they are chemically different substancesB. the government defines drugs and medicines separatelyC. medicines are used to cure, treat, and prevent diseasesD. drugs cannot be purchased in pharmacies

A.they are chemically different substances

Explanation:

Drugs and medicines are two different thing though pepole tends to use the word interchangeably. Drugs are not considered as medicine because of the fact that they are chemically different substances.

Some drugs gives people the hallucinating effects instead of to cure, treat or prevent diseases hence the reason why it is banned and a heavy fine given to some caught with it.

Medicine on the other hand, are meant to prevent or cure diseases. most of this could be purchased without the doctors prescription in the pharmacies.