... Does this prevent me from writing a fictitious book about an evil pharmaceutical company called "Scabby" ?
Books have been written about evil pharmaceutical companies in the past, both fictional and nonfictional. "Scabby" could be an interesting read.
If you are serious about writing about your experience, you should have your manuscript personally reviewed by a publishing law professional prior to publication, to make sure you do not cross any legal lines (into, for example, defamation territory).
Again, I wish you good luck.