Is 75mg of diphenhydramine hcl in one sitting safe?

Hi Laura,
It’s good you brought up this topic of the combination drugs.
It’s a good habit to look at the contents prior to buying.
Acetaminophen is one that is used in combination drugs. You need to total that amount with your daily dose because 4 grams can cause liver failure.
So back to the Benadryl...
75mg will cause excessive sleepiness unless it’s used frequently which you don’t.
I’d be a bit nervous if you have sleep apnea.
Your mouth is going to be dry so I’d sleep with a glass of water on your bedside table.
Be careful when getting up in the morning because it may cause dizziness which increases the chance of falling.
Hopefully, you won’t have to drive. Taking the 75mg May cause your reflexes to be slower.
Best wishes
:-)