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.
The most commonly cited method is giving acetaminophen every four hours and ibuprofen every six hours. However, this timing is problematic in that it exceeds the recommended daily doses of each medication and does not specify which medication should be given at the 12th hour (Carson, 2003; Mayoral et al., 2000).