eli5 does our immune cells try to attack the medication we take while we’re sick? Since medicine is a foreign object. Or does it think of it as a friend who’s there to help.

Question

eli5 does our immune cells try to attack the medication we take while we’re sick? Since medicine is a foreign object. Or does it think of it as a friend who’s there to help.

In: Biology

Answer 1

Most medications are small molecules, too small to fit the machinery different types of immune cells and non-cellular elements use to recognize and attack things. These mechanisms evolved to target things on the scales of proteins and (large) sugars.

Drugs that *are* on that scale, like monoclonal antibodies, can indeed be recognized and cleared, making the drug ineffective.