One is designed to relieve cold symptoms, one is a sleep aid. Both are antihistamines, and in fact both are diphenhydramine. Are they pretty much interchangeable as far as usage? Are the recommended dosages different, or perhaps other factors like absorption rate?
They are the exact same drug. Diphenhydramine is a first generation antihistamine, it is indicated for allergies and as a sleep aid. The only difference between them is that for allergies an adult takes 25mg to 50mg, and for sleep you take 50mg.
It’s an example how a side effect for one use can be the desired effect for another use.
Sounds like Viagra to me.
Thanks. So it would just be best to buy whichever is cheapest for both purposes?
Yes, just buy whatever is cheaper. I’ve noticed at the drug store I work at, the generic diphenhydramine is different prices depending on what it says. The exact same size bottle, with the exact same ingredients, the one marked as allergy was cheaper then the one marked for sleep.