I dont Rx anything for anyone who isn't my wife or parents. Anything you do outside of your official duties at work isn't covered by your malpractice. There's been doctors who lost their life savings in malpractice suits by treating friends. The risk management monthly cme podcast (not sure if this still exists) scared the hell out of me by covering cases in the legal literature about this and ever since then, I don't prescribe anything to anyone who isn't someone I'm absolutely certain isn't going to bankrupt me.
One case I remember them discussing was two doc friends; one had gout and asked the other to Rx colchicine. He did. The guy had an anaphylactic reaction and died. The wife of the deceased sued him for malpractice and won, insurance didn't cover since it wasn't part of the docs routine duties at work, and the guy lost his life savings.