adhd with odd

My husband was diagnosed with adhd in 2008, my daughter was recently diagnosed as having adhd as well. Last month she said she also has oppositional defiant disorder(ODD), and that this is probably being more damaging to her life than adhd itself. She prescribed SERTRALINE to treat it. But my husband´s doctor told me ODD is not usually treated with medicines. I read about this medicine and felt scared. I don´t know what to do. Please help! Is this prescription right? Is this medicine the right treatment for Odd?