What Are The Harms Of Taking Medication For Bumps On Skin?

hi ,i have this small problem with the skin zits ,i am talking about that with the help of makeup i can caver them .....i went to a dermatologist today and he give me some pills (cups isotroin 20 mlg) and i have to drink them for 5 months ,3 times a day ...i want to know how bad are this pills for me ,ohhh and something else he told me that i must not get pregnant for 1 year .thank you alot