The only reason you might hear of something like that is because of a production problem which will curtail supplies for a bit. Production will pick back up once the problem is solved. That happened with Upjohn's depo test a few years back. My pharmacy was scraping to keep prescriptions filled, calling every place they could to see if they had some. Luckily now, there is finally a generic version so Upjohn does not control the whole supply any more.