After taking metronidazol500mg for tooth infection which ruined my system.no appetite, nauseous, diarrhea.. my blood result came as bun is 4 and bun/creat ratio is 5.7 and egfr is 111. the doctor i saw told me its still normal. do you agree?

Above tests reflect your kidney function that remains normal, not explaining your symptoms that may or may not be due to metronidazole.

The blood test results here or not alarming, although it would be better to see the rest of the blood test results and no the clinical situation to help interpret them. It is not clear whether the symptoms you’re having or due to the metronidazole or not. If your nausea, diarrhea, and lack of appetite persist, return to your physician for further evaluation. Good luck.

Yes I agree. Your symptoms could have been caused by the med. Best is to discuss their cause and treatment with your doc and not concentrate too much on the lab reports. Hope you feel better

Your doctor probably mentioned this, but it's worth repeating that you should make sure to avoid alcohol while on metronidazole. The combination causes intense GI distress, especially nausea and vomiting.