A decrease in susceptibility to a drug after continued use of the drug is known as:

tachyphylaxis

Explanation:

Addictive or tolerance - unofficial name.

This is accompanied by the addiction of the body to the medicine. The receptors memorize the chemical substances of the drug and when they are reintroduced, they do not react to it. In this case, the medicine is rapidly eliminated from the body as drug is not digested

A decrease in susceptibility to a drug after continued use is known as tolerance.