I'm dealing with bad allergies right now, and it is causing post-nasal drip with is making me vomit. will benadryl (diphenhydramine) help me?

Yes.: Benadryl (diphenhydramine) is commonly used to treat symptoms of allergies. It tends to work faster than other allergy medicine but it also causes more side effects, especially sedation. Some people get the opposite effect and a jittery feeling. If allergies are an ongoing problem consider a daily medication like allergies, Claritin or zyrtec. They take longer to work but tend to have fewer side effects.

Allergies: There are several over the counter antihistamine pills besides Benadryl (diphenhydramine) including claritin, allegra, zyrtec which may cause less drowsiness than benadryl (diphenhydramine). There are also prescription nasal sprays which are good for post nasal drip. If symptoms persist see a doctor for evaluation.