I'm afraid my brother is going to overdose on his Gabapentin he weighs approximately 160 pounds and I need to know how many 300 milligram gabapentin it will take for him to overdose

What mgs does the bottle say to take and what is he actually taking?

what mgs does the bottle say to take and what is he actually taking?300mg 2 times a day. He took 30

30 pills? Sounds like he better get to the ER, is he having any symptoms? Why did he take that many?

Yes, that can do it, get him attention now