First Aid USMLE Step 1 Int'l vs. US edition?

I recently ordered First Aid off a third party seller on Amazon since it was cheaper than Amazon's going price and when I got the tracking info I found out that the book will be the international edition. I contacted the seller about this and they said that both the international and US editions are the exact same book. Just wondering if this is truly the case or if I should return the book for a refund and just buy the more expensive (US edition) copy?
Source: Student Doctor Network - Category: Universities & Medical Training Authors: Source Type: forums