Businesses, including physician practices, can create something similar: pages (previously "fan pages"). Anyone on Facebook who elects to "become a fan" or like your page receives, on his or her own home page, any updates, photos, videos or Web links that you post.
Rather than having patients "friend" you on Facebook, you can direct them to this page. Having a moderator is important, because having someone dedicated to responding to people makes them feel more connected and encourages respectful and on topic discussions.
References:
Amednews: How Facebook fan pages can connect with patients.
Facebook Pages Manual.pdf - File Shared from Box.net via @sandnsurf.
Updated: 07/15/2010