1. something that is to happen or has happened to a particular person or thing; lot or fortune. 2. the predetermined, usu. inevitable, course of events. 3. the power or agency that determines the course of events.
Alternating between ibuprofen and acetaminophen every 2 hours because you have to wait 4 hours for each of them to take a second dose of the same thing. So instead you take a dose of Acetaminophen now, then Ibuprofen in 2 hours and back to Acetaminophen 2 hours later as needed.
Probably best to stick to the recommended dosing on the bottle though. For adults, that's 400-800mg four times a day (Maximum 3200mg/day US labelling or 2400mg/day Canadian labelling) Dosing for children is weight based. If your symptoms persist for more than 24 hours with ibuprofen, you should probably see your physician rather than keep taking the drug. Unless you are allergic to it, or have gastric issues such as ulcers or gastritis. Or have kidney disease, or advanced liver disease, or heart disease, or late in pregnancy.