My Mother Is 83 Years Old. The Dr Recently Started

My mother is 83 years old. The Dr recently started her on Ranitinide 150mg. She also takes Warfarin. After taking the Ranitinide she starts experiencing heavy heartbeats, hearing heartbeats in her 'ears'. Her INR today was 3.8. I'll call her DR in the morning, but does this med usually cause heart symptoms? Thank so much, Patricia