If both your kidney and liver functions have gone down, which is better pain med, tylenol (acetaminophen) or ibuprofen?

Why were they up? It depends on what caused kidney / liver markers to go up. The liver self-repairs better, so if had to choose, would say tylenol (acetaminophen) and "regular" strength variety, not to exceed 3 grams / day maximum. Always ask your dr if specific concerns.