Typically the meds are used to counteract an acute episode, and then continued as a prophylactic against a relapse of those symptoms. That's the norm with psych meds, whether they're indicated for long-term stability or not. So the short answer to your question is no, they will not be added and subtracted according to your episodes. They'll be frequently added and seldom taken away.

This is the methodology that has the average bipolar person on a 3-4 med cocktail at any given time.

I take a mood stabilizer and an atypical antipsychotic as my front lines against relapse. There are other meds in my cocktail, but those are for things other than mood episodes. I've been stable on this combo for well over a year, and not once has my doc suggested subtracting one of the meds or reducing dosages. He just wants to leave well enough alone.