Can I prescribe my girlfriend zofran?

I am a PGY3 internal medicine resident who's about to graduate in 2 months. My girlfriend and I are planning a vacation to Tulum, Mexico, where tap water is not drinkable. I want to prescribe zofran to my girlfriend so that in case we run into food poisoning/etc, we have zofran to take at the very least. Is there any way I can get in trouble for this? I am still under a hospital issued NPI number.
Source: Student Doctor Network - Category: Universities & Medical Training Authors: Tags: Internal Medicine and IM Subspecialties Source Type: forums