Do Trapic And Sevista Have Side Effects On Long Term Usage?

I suffer from multiple fibroids largest being around 6cm. Because of this I am having very heavy and irregular periods. My doctor have prescribed sevista 30 twice a week and Trapic 650 thrice a day during periods. These I have been taking on and off for almost a year. I want to know how long this treatment can be continued without side effects.I am 49 year old.