Woke up in pain because of back tooth. dentist prescribed brufen 400mg and remove tooth in 5 days. brufen help 1hr then stop. should i take 2 at once?

Yes: Yes. You can safely take up to 800mg of ibuprofen 4x daily. Taking antibiotics will help more than the ibuprofen. Also, sometimes narcotics are needed to control initial pain.

Increase OTC meds: Maximum prescription dose of ibuprofen is 800 mg at a time (2400 mg max per day); you can also add extra strength tylenol (acetaminophen) every 8 hours.