The need-to-know information for Diphenhydramine (Benadryl)


Pearls and Fun Nuggets

1. Diphenhydramine was the first prescription antihistamine approved by FDA šŸ†It was discovered in 1943 by George Rieveschl, a former professor at theĀ University of Cincinnati.[66][67]Ā 

2. It also helps you sleep šŸ˜“ Because of its sedativeĀ properties, diphenhydramine is widely used in nonprescription sleep aids for insomnia. The drug is an ingredient in several products sold as sleep aids, either alone or in combination with other ingredients such asĀ acetaminophenĀ (paracetamol) inĀ Tylenol PMĀ orĀ ibuprofenĀ inĀ Advil PM.

3. Don’t drive a car while on diphenhydramine šŸ˜³ A typical dose creates driving impairment equivalent to a blood-alcohol level of 0.10, which is higher than the 0.08 limit of most drunk-driving laws.[20]

4. Diphenhydramine is sometimes abused šŸ˜£ People with mental health problemsā€”especially those with schizophreniaā€”are also prone to abuse the drug, which isĀ self-administeredĀ in large doses to treatĀ extrapyramidal symptomsĀ caused by the use ofĀ antipsychotics.[78]

Patient Perspectives

“Works well and is one of my to go-to antihistamines. However it is very sedating and is also not long-lasting. It would work great for someone with insomnia as a milder sleep-aid, but for my use I would say that it works, but makes you sedated.”


“I have no rest every time I take benadryl. I feel I have a really bad reaction as I feel restless, my body feels like itchy, nauseous and it makes me feel angry feeling restless it really hurts my stomach am I allergic to it? or it a bad reaction”


“I’ve used this and given it to my children for over 20 years. My teenage son would take 1 before going to bed so he could sleep without allergic reactions. I’ve used it for unknown allergies like bee stings and sunless tanner. Works great and so does the topical cream. No adverse affects with us.”

Brandon Simpson, PA-C
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