Ibuprofen is completely eliminated from the body in 24 hours after taking the final dose. Peak concentrations of the medication affect the body within 1 to 2 hours, according to National Center for Biotechnology Information.
Prescription Ibuprofen is commonly used to treat pain, inflammation and tenderness caused by certain forms of arthritis, according to MedlinePlus. The nonprescription form is used to treat fever and relieve minor aches and pains. The usual dose is 400 to 800 milligrams three times per day.
Because the drug does not stay in the system for long, per dose it causes fewer stomach and kidney problems, states The Harvard Medical School Family Health Guide.
Old age has no affect on the elimination time for the drug, nor does renal impairment, reports NCBI. The rapid elimination of ibuprofen is due strictly to metabolism within the body. Ibuprofen can cause a variety of gastrointestinal side effects such as constipation and diarrhea and should only be taken as directed.