Benadryl + Zantac for Rash

Amy, a 26 year old woman, came into the pharmacy a few days ago.  She had a red, itchy rash on her arms and belly since yesterday.  She also had two little girls with her grabbing her arms and demanding their mama’s attention NOW! 


When we were in pharmacy school, we were taught to spend 15 to 20 minutes asking questions to clarify the issue, explaining the options, reviewing side effects, etc.   However, reality is, this mom had about 2 minutes before the kids went into melt down mode!


So, in short, if a patient is having a short-term bad allergic rash (like from food, poison ivy, dust) the best way to nip it in the bud is to take…


1.     Benadryl(diphenhydramine) 25mg -1 to 2 tablets every 6 hours

2.     Zantac(ranitidine) 150mg – 1 tablet every 12 hours


If she had more time, I would also mention that Benadryl can make her drowsy but works faster than Claritin (loratadine) and Zyrtec (cetirizine) and that she could use Pepcid (famotidine) instead of Zantac. 


Also, that oatmeal baths(home-made or from Aveeno) will help with the itchiness.  And if she doesn’t see a big difference in 2 days or if it gets worst she should see her physician for some prescription drugs.


Oh yeah, if she really wanted to stick around, I would also explain that we have two different histamines in our bodies –H1 and H2- that can cause the rash.  Usually Benadryl (works on H1) is enough but sometimes we need to add Zantac (work on H2).  


But in truth, she said she would just take my word for it.  She did call back today (I could hear the girls in the background) and said the Benadryl made her very drowsy but that the rash was gone!   

Any questions/comments/stories of your own?  I would love to hear from you -leave a comment or email me at

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Thank you for your post. My husband has had a rash ever since his shingles vaccine. He is now running a fever and this has been going on for 4 weeks. Phone call to doc and he said zantac and benedryl and that really confused me til i talked to the pharmacy. Your post is the only one i found regarding this matter. Husband has also done a round of Medrol, that cleared it up but it came back again.

Hi Cheryl,

Thank you for leaving a comment! Sometimes, it can take a couple of rounds of Medrol, Zantac and Benedryl -frustrating but true. How did the addition of Zantac and Benedryl help?

Take care,

Nova Simpson, Pharm.D.

My mother has been having Chronic Urticaria for years, no doctors can help her it get really bad and then for a while she is perfectly fine- Recently I heard that taking Benadryl with Zantac can help- she is going to try this- do you have any other suggestions for her.

Thank you,

My dr just prescribe zantac for itchie arms. I do not have a reash but both of my arms itch so bad that it wakes me up every night and I have to Keek an ice pack with me at all times. The ice is the only thing that’s stops the pain the itch. I hope this works because I am getting tired of not sleeping.

allegra and zantac in the morning and benadrl and zantac at night really helps with chronic urticaria

I have a very bad rash, back , arms and top of legs. Went to er and to a walk in clinic,Ho gave me creams. Neither worked. At night it is burning so bad you would think I had put the iron on my body. Awake most of the night. I will try this and pray it helps. Thank you

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