My mother continues to enable my drug addicted brother. How can I keep him away?

My brother has been in and out of Rehab for years, stealing off of everyone, he recently got our mother addicted to pills, she is 71 he is 51, he just totaled his 3rd car, my mom was with him, she's been in ICU for 2 weeks, she's improving, they are sending her home shortly, she is clean and healing, my dad is concerned my brother will come around and cause undo stress again. My mother baby's him and won't say no, what can I and my other siblings do to prevent him from going to our parents house, his objective is to cause my dad a lot of stress and have him leave or worse so he can move in and take over, We want him to leave our parents alone while they are still healthy. Any suggestions would be a blessing,!Can I put a PFA against him?