Generally taken every 6 to 8 hours, the maximum dose of NSAIDs per day is 2400 mg which is 12 over-the-counter tablets. Liver-safe: Ibuprofen and other NSAIDS rarely affect the liver. Unlike acetaminophen (Tylenol) most NSAIDs are absorbed completely and have negligible first-pass hepatic (liver) metabolism.In other words, the way NSAIDS are metabolized makes liver toxicity (hepatotoxicity) very rare.buprofen and other NSAIDs inhibit prostaglandins, and that can cause a problem because prostaglandins dilate blood vessels leading to the kidneys. Inhibiting prostaglandins may lead to kidney ischemia (dead tissue from decreased blood flow) and thus acute kidney injury.