Usually, yes you can, they are not the same medicines. Both are NSAIDs however Ibuprofen does not thin your blood, nor should it cause an allergic reaction if you are allergic … to aspirin. Always check with your doctor if you are unsure about taking a medication.hey are all NSAIDS and can help you feel better from aches and pains, reduce inflammation such as swollen sinuses, etc. and treat fever. But those under age 18 should not take aspirin when they may have a virus or flu since there is a risk of Reye's Syndrome with that medication use with some viruses.