Oral minoxidil is called loniten. It is a blood pressure medication with a quirkly side effect: it grows hair. With that said, topical minoxidil is much better at stimulating hair growth than the internal version.
The story linked above also involves the long term use of finasteride as well as oral spironolactone for a year - according to Dr. Proctor it can take this long to regain frontal hair. For this reason, I'm not so sure I'd chalk up his success to using oral minoxidil.
As for saftey information on loniten, I have little idea. I'm almost certain the topical is much safer.