Does High Dosage Of Ibuprofen Lead To Sleepiness?

i took one 500 amox and one 600 ibropfrofen at 10:30am and inadvertently took the same dosages at 3:00 pm this afternoon. now its 4:07 pm and i feel sleepy...is this normal reaction if i had too many in less than 5 hours? i usually take them every 8 hours....