I had a tooth pulled Friday morning and was given erythromycin for the abcess. Instructions say “take with food” but I haven’t eaten since Thursday because first the tooth hurt and now the hole hurts (never mind my jaw. If I ever get my hands on the guy who shoved that golf ball in there he’s a dead man.).
What am I doing/could I potentially be doing to myself?
The worst you’ll get is an upset stomach or diarrhea.
For one dose that’s likely true. However, as I understand it, taking several doses that way can lead to problems with the stomach lining, and possibly ulcers. Again, this is simply expanding the worst case scenario - if you’re not experiencing discomfort after taking those meds that way, it’s not likely a problem. A better person to ask is your pharmacist.
IANADoctor, what was stated above might happen. Also, the effect of the medicine may come on quicker, as the stomach is empty and there is no food the help absorb or slow down digestion.
You’ll be hungry.
I’ve been hungry!
Remember, “take with food” doesn’t necessarily mean that you have to eat a thick steak, just something to protect your stomach lining. Think thick milkshakes or smoothies, creamy soups, stuff like that (just make sure the pills don’t advise against taking them with dairy products, as some do).
Oddly, this site tells you to take it one to two hours after eating, and not to take it on top of fruit juices or carbonated beverages. Talk to the pharmacist - they often know more about these kinds of drugs than the doctors do.
IANADoctor, but I did manage to screw up my esophagus by taking ibuprofen without eating first. However, I was taking the ibuprofen several times a day for a few weeks before the damage made itself known to me. I was also smoking and drinking a lot of coffee at the time, which probably didn’t help anything. If it’s just for a few days, until you feel well enough to eat, you should probably be okay.
You do need to get some food in, though. Or juice. Or something with nutrients.
I was under the impression that the reason things are taken with food is because they are fat soluble and need the fat in the food for proper absorbtion.
Just like the “good” brownies. 
If you really don’t fell well enough to eat ‘food’, at least get enough liquid or thick liquids to help dissolve the pills and get them past the stomach and into the gut. This will help to reduce the risk of stomach upset.
I think the real problem is folks having upset stomachs and then stopping the medications.
take a few ginger pills with your other pills they will keep your stomach from getting upset. you can get them in the vitamin section at the grocery store or whatever or you could eat food but whats the fun in that or you can drink milk (no OJ) and that helps the stomach a bit