Does someone who has hidronephrosis can take anticeptic pills?

Unsure but?: If one has hydronephrosis, there is blockage. If there has not been a stent placed to get flow around the blockage or even if it has, antibiotics are often prescribed and needed. A stagnant urinary system is a set up for a severe infection.

Yes: I think you mean contraceptive pills. It is ok to do so as long as you don't have hypertension or advanced kidney failure.