Question

Many people use over-the-counter drugs for all sorts of pains and don’t really pay attention to the long term side-effects. (compound)

Answer 1

Many people use over-the-counter drugs for all sorts of pains; they don't really pay attention to the long term side-effects.

or

Many people use over-the-counter drugs for all sorts of pains, and they don't really pay attention to the long term side-effects.

(you can use any of the other fanboys if and doesn't make sense).