Is Benadryl a helpful first-aid treatment for venomous snakebites? No, that's not true: This anecdote about using Benadryl as a part of first-aid care for a person who has been bitten by a venomous snake is not supported by evidence or the current advice for emergency care of snakebites by toxicology experts.
The story seems to have appeared on Facebook on July 1, 2019, and was copied and pasted. One example is this post (archived here) where it was published on July 18, 2019. It opened:
Repost from a friend........For all of us in Rattlesnake country: I have learned something new that I thought was important enough that I wanted to pass on. A friend was bitten by a rattlesnake a few days ago. Luckily it was not a severe bite, the fang marks were clear, but not deep enough to draw blood. He came straight to the house and we got ice on it and had him to the hospital within an hour. I called ahead so the emergency room was ready for him. By the time he got there his arm was starting to swell to the shoulder and his throat was getting tight. The first thing the emergency room did was give him Benadryl. anti-venom must be received within 4 hours of the snakebite, but the immediate threat is swelling and death of tissue, which was treated with the Benadryl.
This is what the post looked like on Facebook at the time of writing:
(Source: Facebook screenshot taken on Mon Mar 15 18:14:15 2021 UTC)
The post continues:
The swelling in his arm and throat started going down right away. The anti-venom medicine had to be prepared and was not ready for a couple of hours. He ended up getting two doses of antivenom and spent the night in the hospital, where they drew blood every three hours, but came home healthy the next day.A nurse, told me to go buy the children's chewable Benadryl for my emergency kit, it won't spill or break.It is given according to body weight, so can be used for adults also, just give a larger dose. She said if you chew it and hold it in your mouth it will absorb just as fast or faster through the membranes of the mouth than from the stomach, which could save a life.I copied and pasted this bc thought it was good info!
At the time that these copy/paste posts were going viral, Nick Brandehoff, M.D., a medical toxicologist and head of snakebitefoundation.org felt compelled to counter this disinformation with facts. The Snakebite Foundation is a 501(c)(3) nonprofit international group of doctors who are working to provide training and establish clinics in areas where tropical snakebites and improper or limited access to care cause snakebites to be a serious public health threat. Dr. Brandehoff is also an assistant clinical professor of emergency medicine at the University of Colorado School of Medicine. On July 3, 2019, he listed four important points explaining why Benadryl is ineffective for treating a venomous snakebite. He posted this onto the Snakebite Foundation website and to Facebook:
Hi Everyone, I wanted to address the poor information about the use of Benadryl (diphenhydramine) making the rounds on...
Posted by Nick Brandehoff on Wednesday, July 3, 2019
Another expert who weighed in was Spencer Greene, M.D. He authored an article about snakebite management for alabamaherpsociety.com. Dr. Greene wrote:
Lastly, remember that Benadryl (diphenhydramine) provides no benefit following snakebite. Benadryl is an antihistamine. Histamine is not a major component of snake venom, so antagonizing the effects of histamine accomplishes nothing. It does not "buy time" or "reduce inflammation" or anything of the sort. All it does is give people a false sense of security and distracts them from the most important thing: getting to the hospital so that someone can determine the need for antivenom, which is the definitive treatment for snake envenomation. The only time Benadryl may be helpful is in the rare case of an allergic reaction to either the venom or the antivenom. And in serious reactions, the drug of choice would be epinephrine, not Benadryl, which helps for hives and itching but not the cardiac or respiratory complications.
The Facebook post also includes mention that ice was purportedly applied to the snakebite victim's arm. Ice is also not part of modern first-aid advice for snakebites. Both the Mayo Clinic and the CDC fact sheet for snakebites break the instructions down into what should and should NOT be done. On either fact sheet, applying ice is on the NOT TO DO list.
