Is there a specific mechanism for the delivery of pain medication?

Question

For example, when one takes aspirin or ibuprofen does the chemical get dispersed to all pain receptor? My question really is, how does the chemical know where to target in the body? I figure wherever there is pain in the body that a certain signal is being produced; which possibly acts as a chaperone to direct the medication chemical where to bind and inhibit.

Answer 1

Most Injected or orally taken pain medications get distributed all over the body. Like pouring kool-aid mix in a pitcher.

They interact with where there is pain, but nothing specifically guides them there.

It is because of this people experience side-effects. For instance, Opioids block pain, but they also affect the digestive tract and tend to make you constipated.