Antihistamines Losing Effectiveness

I have been on several antihistamines over the years and they eventually lose effectiveness. All of these medications were prescribed by my allergist. Over the years I have taken Claritin, Allegra, Zyrtec, Xyzal, a combination of Claritin and Allegra, a combination of Zyrtec and Xyzal, a combination of Xyzal and Allegra, and etc. None of them prevent allergy symptoms anymore. Benadryl has also lost effectiveness and now only 75mg of Benadryl helps my allergy symptoms. I can only take this dose at bedtime. I also use Patanase and Nasonex on a daily basis.

What antihistamine(s) have you found helpful?

Have you discontinued using an antihistamine because it has become ineffective?



Comments 6

  • Kathy P

    I've definitely had that issue too. Currently I take Xyzal at bedtime and Allegra or Claritin if needed in the morning. And yes, sometimes, it still feels like it's not enough.

    One thing that has helped for me is allergy shots. I don't know if you have looked at that as an option before or not.

  • Shea

    I take benadryl every night. It has always been my go-to antihistamine. But I too feel like it might not be as effective as it used to be. My primary treatment is strict avoidance of what I am allergic to. Rotating antihistamines could be an idea. 

  • MMKB

    Thanks for your replies. Yes, I have had a series of allergy shots 3 different time over the years. Each time the doctors told me I had to stop because I was having reactions to the shots. My new allergist wants to discuss starting allergy shots again at my next appointment. I'm willing to try again, but I'm not very optimistic.

  • Kathy P

    Ugh on having reactions to the shots. I actually have to go higher than the typical maintenance dose and I hate them because they hurt so much! I haven't had to stop because of reactions, but I've had to build up more slowly. It's definitely a time commitment.

  • K8sMom2002

    Hugs on the antihistamines losing their effectiveness … what sort of things are you allergic to?

    Like you, DD isn't able to take shots anymore (completely off the table, according to her docs). Because of another health issue, she can't use steroid nasal sprays, either. 

    Avoidance is tough, but it's the thing that has helped both me and my DD. We use a lot of different approaches … 

    • an asthma & allergy friendly™ certified filter in our HVAC system
    • a vacuum with a HEPA filter/bag (it's asthma & allergy friendly™ certified as well)
    • avoiding known triggers 
      • DD avoids outdoors when pollen levels are high
    • washing sheets in hot water
    • showering before bed
    • using saline spray and gel frequently during the day (her doc says she can use those as often as she needs, and that does seem to help)

    Here's more on the asthma & allergy friendly™ certification program:

    The asthma & allergy friendly™ Certification Program, administered by the Asthma and Allergy Foundation of America (AAFA) in partnership with the international research organization, Allergy Standards Limited (ASL), is an independent program created to scientifically test and identify consumer products that are more suitable for people with asthma and allergies. You can find certified products and services such as carpet cleaning, flooring, vacuums and more at 

    Could you ask your doc about any other meds that you could take during especially tough allergen seasons?