Fasting before blood tests...question...?

I'm taking a blood test that requires fasting 6-8 hours beforehand. The problem is, sometimes I wake up in the middle of the night and can't get back to sleep w/o a small amount of aspirin (and water to take it with). I have itchy, dry skin and we live near a field, which I think makes it worse being allergy season. I'll take a tiny amount (quarter tablet) just to stop the inflammation. Someone at the clinic told me this was ok and wouldn't affect the test the last time I had bloodwork drawn. But this time I'm having tests done on my kidney function in additional to the routine bloodwork, so just wanted to make sure it wouldn't make a difference. Does "no eating and drinking for 6-8 hours" even include water and medicine, or would it be best to abstain from that, too? Thanks.