\ Interactions \

Diphenhydramine (Benadryl®) Interactions

In the United States and Canada, Benadryl® products contain the antihistamine diphenhydramine. In the United Kingdom, Benadryl® products contain either the non-sedating antihistamine acrivastine (Benadryl Allergy Relief) or the long acting antihistamine cetirizine (Benadryl One a Day Relief).

Benadryl products are marketed in Australia and New Zealand as cough medicines and do not contain any antihistamine. Benadryl Chesty Cough & Nasal Congestion contains guaiphenesin (an expectorant) and pseudoephedrine as the active ingredients.

Note: The following information applies to diphenhydramine-containing Benadryl® products.

Can you take Benadryl with antibiotics?

There are no known drug interactions between Benadryl and antibiotics.

Can you take Benadryl with other allergy medications?

There are no direct drug interactions, but you are duplicating antihistamines if you take take Benadryl with Zyrtec (cetirizine), or Claritin (loratadine), or Allegra (fexofenadine) at the same time.

Taking two antihistamines together increases the chances of side effects like dry mouth, drowsiness, dizziness, and dry eyes.

Can you take Benadryl with ...

Medication	Comments
Acetaminophen (Tylenol)	Yes, you can. There are no drug interactions.
Ibuprofen (Advil, Motrin)	Yes, you can. There are no drug interactions.
Meclizine (Antivert)	There are no contraindications. Possible additive anticholinergic side effects.
Melatonin	There are no contraindications.
NyQuil	There are no contraindications. NyQuil contains doxylamine, a sedating antihistamine. So it wouldn't be a good idea to take them together since that would be a duplication of therapy.
Prednisone, Prednisolone	Yes, you can. There are no drug interactions.
Promethazine/Codeine	There are no contraindications. Diphenhydramine may slightly reduce the effectiveness of codeine. Promethazine may increase anticholinergic side effects such as drowsiness, dry mouth, flushing.
Pseudoephedrine (Sudafed)	Yes, you can. There are no drug interactions.
Zolpidem (Ambien)	There are no contraindications. Possible enhanced CNS depressant effect of zolpidem.

References:

1. Lacy CF, Armstrong LL, Goldman MP, Lance LL. DiphenhydrAMINE. Drug Information Handbook, 18th ed. Hudson, Ohio, Lexi-Comp, Inc.; 2010: p.456-458

By HealthyStock Research Group, October 23, 2012
Medical resources reviewed: August 2018