Can i take one extra ibuprofen 600mg from instructed twice a day because i have trouble sleeping with the pain?

You could BUT check: With your doc, who might have a reason to give it to you only twice a day. Or he may give you a sleeping tablet.

Pain Alternatives: You could also try alternating tylenol (acetaminophen) 650mg with Ibuprofen 600mg, 3 hours between each dose. Sometimes cold or hot packs to the painful area help. Finally, getting enough sleep is important for managing pain.