600mg of benadryl (diphenhydramine) greatly improves my quality of life. could something be restricting bloodflow in my brain? is there a safe alternative?

Benadryl (diphenhydramine): Depends on why you're taking it and how it helps improve your life. It's quite a lot of Benadryl (diphenhydramine) which may not be safe to take long-term. There is tachyphylaxis with it, which means that you get used to it and need more for the same effect.If you have a bad allergy it really helps (you need to be allergy tested to avoid triggers rather than using a bandaid).Benadryl (diphenhydramine) does not increase blood flow.