A post shared over 9,500 times on Facebook claims that Benadryl, a commercial brand of Diphenhydramine, an antihistamine used to relieve symptoms of allergy, was used to treat a patient bitten by a rattlesnake. Some users appear to interpret that Benadryl is therefore a recommended treatment for a rattlesnake bite. This is false.
The Facebook post ( here ) is from 2019 but, as of March 15, it continues to be shared. It narrates how a person was allegedly treated in an emergency room after being bit by a rattlesnake. “The first thing the emergency room did was give him Benadryl,” the post says. “The immediate threat is swelling and death of tissue, which was treated with the Benadryl.”
Some users appear to interpret that Benadryl is a recommended treatment for snakebites. Comments include: “Good information! Another remedy for snake bite is to make a paste of baking soda and water and apply! It saved my life after a copperhead bit me twice!.” Other users comment that Benadryl could be used to “keep the swelling down.”
Rais Vohra, Medical Director of the California Poison Control System Fresno-Madera Division ( here ) told Reuters via email that “Antihistamines such as diphenhydramine are useful for swelling related to allergic reactions, not venom related emergencies such as a rattlesnake bite.”
In a 2019 article by the Snakebite Foundation here , Nick Brandehoff, a medical toxicologist, wrote that Benadryl is not effective for treating snake envenomations.
“Pit viper envenomations in the US cause local tissue injury from direct venom effect. The cell death causes swelling and pain from the release of intracellular contents as the cell dies,” Brandehoff said. “Furthermore, venom causes blood vessels to become “leaky” resulting in further swelling, redness, and pain as fluid leaves our blood vessels and enter the tissues. Benadryl does nothing to negate these effects.”
Brandehoff wrote that in the “very rare” case of an allergic reaction to a snakebite, Benadryl could possibly play a role in treatment, but that epinephrine would be the principal medication required ( here ).
Jeffrey Suchard, a UCI Health emergency medicine physician and medical toxicologist ( here ) told Reuters via email that “it is possible, although rather unlikely, to have allergic reactions to rattlesnake envenomation.”
According to Suchard, the treating physician mentioned in the post could have “thought the patient’s throat tightness was from an allergic reaction,” and therefore recommended the diphenhydramine. However, “the arm swelling almost certainly was from a direct venom effect, and Benadryl (diphenhydramine) was highly unlikely to affect this swelling.”
Benadryl could have also been used as a “pre-treatment before the antivenom therapy, since allergies to antivenom can occur,” Suchard explained. But this is not a common practice, since “the most commonly used snake antivenom currently in the US has a low incidence of inducing allergic reactions.”
“The best course of action is to get the patient to an emergency room as quickly as possible for antivenin and other treatments as needed,” Vohra told Reuters.
Missing context. Antihistamines, like Benadryl, are not the recommended treatment for snakebites. If bitten, a person should seek medical attention as soon as possible.
This article was produced by the Reuters Fact Check team. Read more about our fact-checking work here .
Our Standards: The Thomson Reuters Trust Principles.