It is safe to take ibuprofen 800 mg and diphenhydramine 100 mg together?

Those are generally very safe drugs and can be taken together. They are both over-the-counter medicines in the us just stay below the max recommended dose both especially ibuprofen because long term use of ibuprofen can cause gastric ulcers also some people with Asthma or heart failure have worsening of their asthma/heart failure when taking ibuprofen or other NSAID's also take ibuprofen with meals diphenhydramine - only side effect is that is makes most people sleepy, but its safe even up to 6 pills a day.