5 Things to Know About Neffy, the New Nasal Spray for Anaphylaxis

Nobody likes getting a needle. But epinephrine auto-injectors, such as EpiPens®, have long been the primary treatment for anaphylaxis, a serious allergic reaction some people have in response to triggers such as peanut butter, eggs, and other foods; bee and other insect stings; and antibiotics, aspirin, and other medications. Without immediate treatment, these reactions can progress rapidly and be potentially life-threatening within a matter of minutes.

But now there is neffy®, a new emergency nasal spray. It’s the first epinephrine product for anaphylaxis treatment that doesn’t involve a needle.

The Food and Drug Administration (FDA) approved neffy in August 2024 for adults and children who weigh at least 66 pounds after giving the product a “Fast Track” designation, which expedites the review of drugs that fill an unmet need for people with serious conditions. Anaphylaxis can affect the whole body, cause such complications as respiratory collapse, and be fatal without quick medical treatment and a visit to the emergency room.

“Many people are very excited about having this new option for patients,” says Mario Rodenas, MD, a Yale Medicine allergist and immunologist. “But, as with anything else, we have to be cautious with neffy,” he says.

One potential issue with neffy is that the clinical trials behind the FDA approval did not test its efficacy on people who were actually experiencing anaphylaxis at the time, since doing so could have led to bad outcomes if neffy was not effective, Dr. Rodenas says.

As a result, he expects many providers will suggest to patients who want to try neffy that they carry both the nasal spray and an injector. If they use the nasal spray and notice either worsening symptoms or do not notice improvement within five minutes, they can administer a second dose or, at the discretion of their doctor, use the auto-injector, he says.

They should also go directly to the emergency room after the use of epinephrine as they need to be monitored in case additional medications are needed for complications of epinephrine use, he adds.

Below, Dr. Rodenas answered questions about what people at risk for anaphylaxis should know about neffy.

An allergic reaction happens when a person’s immune system reacts abnormally to a substance that usually does not cause symptoms. An anaphylaxis attack is a severe, life-threatening allergic reaction. One in 20 Americans have experienced anaphylaxis, and 225 people die from it each year.

An attack can start within five to 30 minutes of an exposure to a trigger. Symptoms can affect multiple parts of the body and include hives, swelling in the throat and other areas of the body, chest tightness and trouble breathing, vomiting and nausea, dizziness and fainting, and low blood pressure, leading to shock.

Epinephrine, also known as adrenaline, is a hormone made by the adrenal glands that helps the body use its “fight-or-flight” response in stressful situations. Synthetic epinephrine is the only lifesaving treatment for anaphylaxis. Many people at risk for anaphylaxis already carry an epinephrine auto-injector that they can self-administer in an emergency.

“If you have a life-threatening reaction, epinephrine is the single most important drug you can use,” Dr. Rodenas says. “It does several things that are good for your body in this scenario. It relaxes the muscles in the airway, allowing for better breathing, and increases the heart rate and blood pressure so that the blood continues to flow to all the major organs. It also stops the release of histamine, the main chemical released by the body in response to allergens that cause allergy symptoms.”

Both neffy and epinephrine auto-injectors are available by prescription only.

Neffy, manufactured by AFS Pharmaceuticals, is sold in a twin pack containing two doses. A single dose of neffy is sprayed into one nostril, and if there is no improvement or symptoms worsen in the following five minutes, a second dose in the same nostril may be given (this is similar to injectable epinephrine, and a reason for carrying two doses at all times).

Neffy is only available to children and adults who weigh 66 pounds or more; the EpiPen, arguably the best-known auto-injector, targets the same age group, but a product called Epipen Jr® can be used for children who weigh 33 to 66 pounds.

“Each method has local side effects that are unique to the delivery area,” Dr. Rodenas says. “With injection, you’re going to have pain in the delivery area, and with nasal delivery, you’re going to have nasal or throat irritation, sneezing, or a runny nose.“

Whatever epinephrine delivery method is used, anyone who has an anaphylactic episode should also go to a hospital emergency room for close monitoring, and in case further treatment is needed.

The FDA approval of neffy was based on four studies involving a total of 175 healthy adults who did not have anaphylaxis. Epinephrine concentrations in their blood were measured after both administration of neffy and approved epinephrine injection products.

The results of the studies showed that the concentration levels of epinephrine in the blood were similar regardless of the delivery method. The two methods also resulted in similar increases in blood pressure and heart rate, both of which are critical to the treatment of anaphylaxis.

Common side effects of neffy include, but are not limited to:

• Feeling jittery
• Gum pain
• Headache
• Nausea
• Sneezing
• Throat irritation
• Tingling nose

Neffy is packaged with a warning that certain nasal conditions, such as nasal polyps or a history of nasal surgery, may affect the absorption of inhaled epinephrine and that people with these conditions should consider injectable epinephrine instead.

Another concern is using neffy to treat an allergy attack that causes swelling, since the nasal cavity can swell up, too, says Dr. Rodenas. “That could, in theory, potentially block the delivery of the drug and its absorption,” he says. “That’s a valid concern and why people carrying an anaphylaxis treatment device should see an allergist. Allergists are the best specialists to determine the most appropriate treatment and delivery method for them.”

There are also warnings and precautions about the use of any kind of epinephrine treatment for anyone with certain co-existing conditions and allergic reactions associated with sulfite, which is included in all epinephrine medications as a preservative.

Co-existing conditions may include disorders such as hyperthyroidism, kidney disease, and heart disease, including cardiac arrhythmias and coronary artery disease or hypertension, among others, which can be exacerbated by epinephrine use.

Anyone with a history of allergies and/or asthma who has previously had a severe allergic reaction to a food, insect bite, or medication is at greater risk for anaphylaxis and should consult with an allergist, Dr. Rodenas says.

“We treat each patient based on their history and prior experiences,” he says. “Some people have had issues administering epinephrine because of a fear of using an injectable device,” he says.

An allergist can also discuss strategies to help prevent anaphylaxis from occurring in the first place. They can provide allergy testing to better understand the types of allergies a person has, as well as instruction on “allergen avoidance”—for instance, how to read food labels properly to make sure a product doesn’t include an ingredient that would be a trigger.

Other therapies for some patients can also include allergy shots and medications such as omalizumab (Xolair®), which was approved early in 2024 to reduce allergic reactions, including anaphylaxis, to foods.

As for the choice between neffy and an injectable to treat a severe allergic reaction, “at the end of the day, there is the question of compliance,” Dr. Rodenas says. “It may be better to have a patient who will use a device they have chosen and are willing to use, as opposed to not using one and potentially dying from anaphylaxis.”