[Acne] What is the point of prescribing antibiotics for acne if they are only effective as long as you take them?

Beauty Tips For Body Care
What is the goal here? As far as I understand and in my personal experience antibiotics only help while you are taking them, and you can't take antibiotics for a very long time without health problems or becoming resistant. So why do dermatologists make you take them before they will prescribe something like accutane?
Girls Blog 2015
Submitted by MarmaladeChainsaw