A person should never mix naproxen and ibuprofen. The two can be taken at different intervals as long as there is an adequate amount of time in between doses.
Both types of medications work the same and have the same side effects. Commonly, ibuprofen can be taken by adults every 6 to 8 hours. Naproxen on the other hand, should be taken less frequently. Before combining any medication, even if it is dispensed over the counter or has been prescribed by a physician, a person should talk to his or her doctor. Individuals should also follow the dosage as printed on medication labels according to their age groups.