The UK’s Prescription Medicines Code of Practice Authority, which arbitrates drug industry self-regulation there, issued “informal guidance” on digital communications, and while it’s more than FDA has offered, it’s not much to go on.
The guidance, which takes the form of a Q&A, is mainly an interpretation of the industry’s Code of Practice applied to social media and the internet. Short version: as in any other medium, companies can communicate only non-promotional information about products to the public, and only in response to a direct inquiry. However, the guidance does suggest that companies could post more basic product info on their websites.