My 2.5 year old may have eaten a 200mg ibuprofen tablet but i can't be sure should i go to hospital?

Not necessary: if the suspected ingestion was only 1 tablet of 200 mg. A standard dose for a child that weighs 24 pounds (11 KG) is 100 mg, so your child would not be in danger of a toxic dose but could get some stomach irritation if taken on an empty stomach. Offer milk or non acid food. No further doses of ibuprofen should be allowed for a minimum of 12 hours.