Possible Clues:

• Final unpleasant moment
• Unhappy outcome
• What some fight until
• Last step, however difficult
• No beer left? That's the limit!
• Something determinedly seen through until the bottom of a pint glass?
• What 17- and 37-Across and 11- and 25-Down each comes to?
• Limit of one's resources
• The limit when there is no more beer
• R? … or a hint to the answers of the five starred clues