8 Neffy (Epinephrine) Side Effects and How to Manage Them

It’s exciting when a new form of a life-saving medication gets approved. In August 2024, neffy (epinephrine) became the first FDA-approved epinephrine nasal spray.

Neffy is an emergency treatment for Type 1 allergic reactions, including anaphylaxis. It’s approved for adults and kids weighing 30 kg (66 lbs) or more. This needle-free option may benefit people who are hesitant or afraid to use epinephrine injections, such as EpiPen.

Knowing more about potential medication risks and getting advice from a healthcare professional can give you the tools to successfully manage allergic reactions.

Neffy side effects at a glance

Neffy shares many similar side effects with epinephrine auto-injectors. But there are certain neffy side effects that happen specifically in the nose because it’s a nasal spray. 

Typically, most side effects are mild and should go away quickly — within about 30 minutes after administering Neffy — but some can last a couple weeks.

Common neffy side effects include:

• Throat irritation

• Nasal tingling, itching, and congestion

• Nasal discomfort

• Headache

• Nervousness and anxiety

• Mouth numbness and gum pain

• Fatigue

• Tremors and shakiness

• Runny nose 

• Sneezing

• Stomach pain

• Dizziness

• Nausea and vomiting

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Rare but serious potential neffy side effects include:

• Heart rhythm changes

• Allergic reactions to sulfite, an inactive ingredient in neffy

• High blood pressure

• Medication absorption problems in people with certain nasal conditions, such as nasal polyps

Below, we’ll detail eight neffy side effects and how to manage them.

1. Throat irritation

Throat irritation is a common side effect that happens with any nasal spray. Since your nose and throat are connected, a dose of neffy nasal spray may drip into your throat. This could cause throat irritation. That’s why it’s best to avoid sniffing while you’re administering neffy — and shortly after.

Thankfully, this is a temporary issue. Your throat should feel better quickly. But there are a few ways to soothe your throat, including:

• Gargling with salt water

• Drinking warm fluids, such as soup or tea

• Trying throat lozenges, such as menthol cough drops

• Taking over-the-counter (OTC) pain relievers like Tylenol (acetaminophen) and Advil (ibuprofen)

EXPERT PICKS: WHAT TO READ NEXT

• Neffy 101: Neffy (epinephrine) nasal spray is a new option for treating allergic reactions. Check out the top facts to know about neffy.

• First-hand accounts: Hives are common with allergic reactions. Read about a few people’s experiences with hives.

• Antibiotic allergies: Antibiotics can be the culprits behind allergic reactions. Learn more about what to watch for when you’re taking an antibiotic.

2. Nasal discomfort

It’s no surprise that neffy can cause nasal discomfort. Like throat irritation, nasal discomfort is a common side effect. But it should go away shortly after using neffy. 

Saline nasal sprays and humidifiers are medication-free ways to ease bothersome nasal symptoms that may be lingering after your allergic reaction is under control.

Good to know: Neffy may alter the tissues that line your nasal cavity. This may cause future nasal spray doses (of neffy or other nasal sprays) to be absorbed into your body more than usual. In turn, this can raise your chances of experiencing new or worsening side effects. However, after about 2 weeks, the tissue in your nose should go back to normal.

3. Shakiness, tremors

It’s normal to experience temporary tremors and shakiness with neffy. 

Epinephrine, the active ingredient in neffy, can raise your heart rate. But epinephrine also acts on your muscles. That’s why you may experience these neffy side effects. The good news is these symptoms should go away on their own. Limiting caffeine and getting a good night’s sleep in the days after your allergic reaction are a couple of tips for managing tremors in the meantime.

Certain health conditions, such as Parkinson’s disease, also cause tremors. If you already experience tremors from one of these conditions, they may temporarily worsen after you administer neffy. Reach out to your healthcare professional if you notice any health changes that don’t get better after using neffy. 

Even if you’re living with health conditions like these, that shouldn’t hold you back from using neffy or another epinephrine product when you need it. Epinephrine can be lifesaving.

4. Nervousness

You’ve likely encountered stressful situations at some point. When this happens, your body releases the hormone adrenaline. This is another name for epinephrine. This process is known as an “adrenaline rush,” or a fight-or-flight response. It can make you feel jittery or nervous.

The same response happens after you administer neffy. This is because it contains epinephrine. Like the other neffy side effects, nervousness should go away after the medication effects wear off. Yoga, breathing exercises, and meditation are a few ways to calm your nerves. Let a healthcare professional know if your nervousness doesn’t go away.

5. Headache

Headache is another common neffy side effect. If you do experience a headache, it should get better quickly. If it doesn’t, there are several strategies you can try to help relieve your headache:

• Drink plenty of water

• Do some light exercise

• Get plenty of sleep

• Take OTC pain relievers

6. Sneezing and runny nose

Nasal symptoms such as sneezing and a runny nose are expected with nasal sprays. Neffy is no different. Again, these should resolve on their own.

If these neffy side effects are bothersome, there are strategies to manage them. Drinking plenty of fluids and trying a humidifier may help. You can also try an oral OTC antihistamine, such as Zyrtec (cetirizine) or Allegra (fexofenadine).

It’s best to wait about 2 weeks to use an OTC or prescription nasal spray after administering neffy. For example, you may want to wait to use the corticosteroid Flonase (fluticasone propionate). Waiting helps prevent too much nasal spray from getting absorbed in your body while your nasal tissue heals.

7. High blood pressure

Neffy can raise your blood pressure. But this is actually a good thing in most cases.

One of the most dangerous symptoms of anaphylaxis is hypotension (low blood pressure). If your blood pressure drops too low, your organs won’t get enough oxygen to do their job. Neffy raises blood pressure by tightening your blood vessels. This is an important part of treating serious allergic reactions.

Your blood pressure should go back to what it was about 2 to 4 hours after administering neffy. If you have hypertension (high blood pressure), you may want you to check your blood pressure at home more often for a certain period of time.

8. Heart rhythm changes

While rare, neffy can raise the risk of experiencing heart rhythm changes in people who have arrhythmias (abnormal heart beats). This risk is higher if you’re taking a maintenance medication for your heart, such as digoxin (Lanoxin). 

In this situation, emergency medical personnel (and your healthcare team) will likely monitor your heart closely after you administer neffy.

Good to know: It’s best to keep an updated list handy with all your prescription and OTC medications. Your prescriber and pharmacist can check for any interactions with neffy that could cause heart rhythm changes.

How to save on neffy

There are ways to save on neffy, which is available as a brand-name medication. GoodRx can help you navigate between GoodRx coupons, copay savings cards, and patient assistance programs to save money on your prescription.

• Save with GoodRx: Anyone with a valid prescription, regardless of insurance status, can use GoodRx to purchase two neffy nasal sprays (1 carton) at an exclusive cash price of $199.

• Save with a copay savings card: If you have commercial insurance, you may be eligible to pay as little as $25 per prescription for neffy using a savings card from the manufacturer.

• Save with patient assistance programs: If you’re uninsured or underinsured, you may be eligible for neffy’s patient assistance program, which offers the medication free of charge.

Why trust our experts?

Written by:

Jennifer Gershman, PharmD, CPh, PACS

Jennifer Gershman, PharmD, is a licensed pharmacist in Florida. She has worked in the pharmacy industry for more than 15 years and is currently a medical writer.

Edited by:

Joshua Murdock, PharmD, BCBBS

Joshua Murdock, PharmD, BCBBS, is a licensed pharmacist in Arizona, Colorado, and Rhode Island. He has worked in the pharmacy industry for more than 10 years and currently serves as a pharmacy editor for GoodRx.

Reviewed by:

Austin Ulrich, PharmD, BCACP

Austin Ulrich, PharmD, BCACP, is a board-certified ambulatory care clinical pharmacist. In his early career, he provided direct patient care in a variety of settings, including hospital and community pharmacies, and in a primary care clinic as a clinical pharmacist.

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