I had to cut things off with a toxic friend. She has bpd. The problem is, she is rude and hurtful to people (including myself) when she doesn't take her meds. She normally tosses them behind a bed when her mom gives them to her. Am I in the wrong?

You don’t need to justify cutting toxic people out of your life (mental illness or not). Mental illness is no excuse to be an asshole. I’m not overlooking the struggles borderlines may face that challenge them from having healthy and consistent relationships. I am making the distinction that enduring those struggles is not an excuse for hurting other people. You’re not wrong for protecting yourself.