My Patients Ask — What about taking Claritin before the COVID vaccine to reduce side effects?

What are your thoughts on taking Claritin before or after the Covid shot? My daughter took it for muscle aches and it worked wonderfully. A cancer research center has recommended it. Have you heard of this?

There are no specific recommendations that I know of to take allergy medications (antihistamines like Benadryl or Claritin) before the COVID vaccination, nor are there any studies showing that doing so is safe or effective.

One expert says, “Antihistamine medications unless advised by your doctor are not likely to prevent a severe allergic reaction to the vaccine, but may blunt the allergic symptoms and make it harder to diagnose the allergic reaction and delay treatment.”

Those I have talked to are saying, “If you have a history of a severe allergic reaction to a previous vaccine, or anything in a vaccine, discuss what to do with your doctor beforehand.”

One allergist wrote to the American Academy of Allergy, Asthma, and Immunology, and asked, “CDC recommendations say not to pre-treat with antihistamines so as to not ‘mask’ a reaction. However, I think for those patients that have known allergies or a background of allergies, pre-treatment makes sense. We tell patients to pre-treat before immunotherapy [and] to pre-treat before aspirin desensitization . . . Antihistamine pretreatment can blunt the severity of a reaction and buy time in management, which might be an advantage in venues where the vaccine is being given by personnel who are not trained in allergy management. Why not pre-treat before the vaccine in patients that have a background of allergy?” 

The AAAAI answer is, “Antihistamines are not contraindicated and can be given before the vaccination, although this approach is not recommended as a routine. One can make arguments either way as to whether this would hide or prevent a more serious reaction. In cases where the vaccine is administered without immediate availability of medical expertise, I would be concerned that the staff might miss a serious reaction if initial symptoms are blunted by the administration of the antihistamine before the vaccination.”

As to what I tell my patients: I don’t recommend pretreating with antihistamines at the present time.


This blog was accurate as of the day of posting. However, as the COVID-19 pandemic rapidly evolves and the scientific community’s understanding of the novel coronavirus and the COVID vaccine develops, the information above may have changed since it was last updated. While I aim to keep all of my blogs on COVID and the COVID vaccine up to date, please visit online resources provided by the CDC, WHO, and your local public health department to stay informed on the latest news.

© Copyright WLL, INC. 2021. This blog provides a wide variety of general health information only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment from your regular physician. If you are concerned about your health, take what you learn from this blog and meet with your personal doctor to discuss your concerns.

This entry was posted in General Health. Bookmark the permalink.