Nayzilam (midazolam) is a prescription drug that’s used as needed to treat seizures. Nayzilam can cause side effects that range from mild to serious. Examples include headache and runny nose.

Nayzilam is used as needed in adults and some children to treat epileptic seizure clusters (two or more seizures in 24 hours).

Nayzilam comes as a nasal spray. It contains the active ingredient midazolam. (An active ingredient is what makes a drug work.)

Keep reading to learn about the common, mild, and serious side effects Nayzilam can cause. For a general overview of the drug, including details about its uses, see this article.

Some people may experience mild to serious side effects during Nayzilam treatment. Examples of the drug’s commonly reported side effects include:

* To learn more about this side effect, see the “Side effects explained” section below.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks and reviews side effects of the medication. If you’d like to notify the FDA about a side effect you’ve had with Nayzilam, visit MedWatch.

Mild side effects have been reported with Nayzilam. These include:

* To learn more about this side effect, see the “Side effects explained” section below.

In most cases, these side effects should be temporary. And some may be easily managed. But if you have symptoms that are ongoing or bother you, talk with your doctor or pharmacist. And do not stop using Nayzilam unless your doctor recommends it.

Nayzilam may cause mild side effects other than those listed above. See the drug’s prescribing information for details.

Serious side effects have been reported with Nayzilam. These include:

* Nayzilam has a boxed warning for this side effect. This is the most serious warning from the Food and Drug Administration (FDA). To learn more, see the “Nayzilam and misuse” section below.
† Nayzilam has a boxed warning for this side effect. This is the most serious warning from the Food and Drug Administration (FDA). To learn more, see the “Side effects explained” section below.
‡ To learn more about this side effect, see the “Side effects explained” section below.

If you develop serious side effects from using Nayzilam, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Help is out there

If you or someone you know is in crisis and considering suicide or self-harm, please seek support:

If you’re calling on behalf of someone else, stay with them until help arrives. You may remove weapons or substances that can cause harm if you can do so safely.

If you are not in the same household, stay on the phone with them until help arrives.

Get answers to some frequently asked questions about Nayzilam’s side effects.

Will I experience different side effects from the first dose versus the second dose of Nayzilam?

It’s possible. In the drug’s studies, there were some differences in side effects between the first and second doses of the drug. Side effects that were more common following a second dose included:

Whether you experience certain side effects of a drug depends on several factors, including your overall health, your age, and other drugs you take.

If you have questions about the side effects from one versus two sprays of Nayzilam, talk with your doctor. They can provide more information based on your individual circumstances.

Does Nayzilam cause long-term side effects?

It’s possible but rare. Most side effects of the drug are mild and should go away when you stop using it.

Nayzilam is only used as needed for cluster seizures. Do not use Nayzilam for more than one episode every 3 days, or more often than five episodes in a month.

This drug can cause dependence and addiction with long-term use. Dependence is when your body gets used to a drug and needs it for you to function as usual. Addiction is when a drug is taken even if it’s causing harmful effects.

If you’ve become dependent on Nayzilam, suddenly stopping the drug can cause withdrawal symptoms in some cases. These are side effects that can happen when you stop taking a drug your body has become dependent on.

Dependence, addiction, and withdrawal are boxed warnings for Nayzilam. See “Side effects explained” below for more information.

Talk with your doctor about long-term side effects of Nayzilam that concern you.

Learn more about some of the side effects Nayzilam may cause.

Risk of dependence and withdrawal

Nayzilam has a boxed warning about the risk of dependence and withdrawal. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). It alerts doctors and patients about drug effects that can be dangerous.

Dependence is when your body gets used to a drug and needs it for you to function as usual. This can lead to withdrawal symptoms which are negative side effects than can occur when a drug is suddenly stopped. Symptoms of withdrawal from Nayzilam may include:

What might help

To avoid withdrawal symptoms, use Nayzilam exactly as your doctor has instructed. It’s only recommended for use as needed for cluster seizures with epilepsy.

If you need to stop using this medication, your doctor will have you stop it gradually to help you avoid withdrawal symptoms.

If you’re concerned about dependence and withdrawal from Nayzilam, talk with your doctor. They can discuss the risks and benefits of this treatment with you.

Risk of problems if used with opioids

Nayzilam has a boxed warning for the risk of serious side effects if used with opioids. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). It alerts doctors and patients about drug effects that may be dangerous.

Examples of opioid medications include:

Using Nayzilam with an opioid drug can slow the activity in your central nervous system (your spinal cord and brain). This can cause serious side effects including:

Due to these risks, your doctor will only prescribe Nayzilam with an opioid if the benefits outweigh the risks of using both drugs.

What might help

If your doctor recommends an opioid with Nayzilam, they’ll prescribe the lowest dose of each drug. This will help reduce your risk of serious side effects. You should take these drugs exactly as prescribed. You should also avoid alcohol with these medications as this can increase your risk of severe side effects.

If you have a caregiver, your doctor may wish to talk with them about opioid overdose warning signs to look for, such as slowed breathing. And they may recommend that you and any caregivers have Narcan (naloxone) available to quickly treat an overdose.

If you have symptoms of respiratory depression, you or a caregiver should call 911 immediately.

Headache

Headaches were a common but mild side effect reported in Nayzilam’s studies.

What might help

In most cases, headaches are a mild side effect of this drug. But if they’re bothersome, call your doctor. They can discuss your symptoms and offer suggestions to ease your discomfort. For mild headaches, they may suggest an over-the-counter pain reliever such as ibuprofen or acetaminophen.

Throat irritation

Using Nayzilam may cause throat irritation. This was a mild but common side effect of the drug reported in studies. The risk of throat irritation may be higher if you use two doses of Nayzilam.

What might help

Since Nayzilam is only used as needed, throat irritation is typically a mild side effect of the drug. If your symptoms are bothersome, talk with your doctor. They may suggest ways to manage your throat irritation such as gargling with warm water.

But if your throat irritation is accompanied by wheezing, or you’re experiencing breathing problems, call your doctor right away. These could be signs of a more serious side effect of the drug. If you feel your symptoms are life threatening, call 911 or get medical help immediately.

Allergic reaction

Like most drugs, Nayzilam can cause an allergic reaction in some people. Symptoms can be mild to serious and can include:

  • skin rash
  • itchiness
  • flushing (temporary warmth, redness, or deepening of skin color)
  • swelling under your skin, usually in your eyelids, lips, hands, or feet
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms. Examples include:

If your doctor confirms you’ve had a mild allergic reaction to Nayzilam, they’ll decide if you should continue using it.

If you have symptoms of a severe allergic reaction, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to Nayzilam, they may have you switch to a different treatment.

Keeping track of side effects

During your Nayzilam treatment, consider taking notes on any side effects you’re having. You can then share this information with your doctor. This is especially helpful when you first start taking a new drug or combination of treatments.

Your side effect notes can include things such as:

  • what dose of the drug you were using when you had the side effect
  • how soon you had the side effect after starting that dose
  • what your symptoms were
  • how your symptoms affected your daily activities
  • what other medications you were taking
  • any other information you feel is important

Taking notes and sharing them with your doctor will help them learn more about how Nayzilam affects you. They can then use this information to adjust your treatment plan if needed.

Nayzilam may not be suitable for everyone. It comes with some warnings, including several boxed warnings.

Boxed warnings

Nayzilam has several boxed warnings. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). It alerts doctors and patients about drug effects that may be dangerous.

Risk of misuse and addiction

Nayzilam can cause misuse and addiction. Misuse is when you use a drug in a different way or for a different reason than how your doctor prescribed it. Misuse can lead to addiction, which is when a drug is used even if it’s causing harmful effects. To learn more, see the “Nayzilam and misuse” section below.

Risk of dependence and withdrawal

Although Nayzilam is only used as needed for seizures, using it over a long period of time may lead to dependence. This is when your body gets used to a drug and needs it for you to function as usual. Suddenly stopping a drug your body has become dependent on can cause negative side effects, called withdrawal symptoms. To learn more, see the “Side effects explained” section above.

Risk of problems if used with opioids

Using Nayzilam while taking opioids can increase your risk of serious side effects. To learn more, see the “Side effects explained” section above.

Other warnings

Nayzilam may not be right for you if you have certain medical conditions. (This is known as a drug-condition interaction.) Other factors may also affect whether Nayzilam is a good treatment option for you. Talk with your doctor about your health history before starting this medication. Factors to consider include those described below.

Kidney problems. Tell your doctor if you have moderate to severe kidney problems. If your kidneys don’t function well, it can take longer for Nayzilam to leave your body. This can lead to a buildup of the drug which can increase your risk of side effects. These include breathing problems and excessive sleepiness. Your doctor may order kidney function tests for you and monitor you closely for serious side effects.

Breathing problems. Using Nayzilam can cause breathing problems. If you having long-term lung conditions, such as asthma or chronic obstructive pulmonary disease (COPD), Nayzilam could worsen your breathing problems. Be sure to discuss any breathing issues with your doctor. They can help you decide if Nayzilam is safe for you.

Impaired brain function. If you have impaired brain function, such as slowed reaction time, poor mental alertness, or problems with short-term memory, Nayzilam could worsen your condition. Do not operate machinery or perform activities such as driving that require mental alertness until you know how Nayzilam affects you. Tell your doctor if you have any problems with brain function. They can determine whether Nayzilam is safe for you to use.

Congestive heart failure. If you have congestive heart failure, tell your doctor. This condition can cause it to take longer for Nayzilam to be removed from your body which can increase your risk of side effects. Your doctor will decide if it’s safe for you to use Nayzilam.

Glaucoma. Be sure to tell your doctor if you have glaucoma. Nayzilam can increase the pressure inside your eye. This drug is not recommended for people with narrow-angle glaucoma. If you have open-angle glaucoma, your eye doctor may need to monitor your eye pressure carefully while you’re using Nayzilam.

Allergic reaction. If you’ve had an allergic reaction to Nayzilam or any of its ingredients, your doctor will likely not prescribe it for you. Ask them about other medications that might be better options.

Suicidal thoughts or behavior. Nayzilam can increase the risk of suicidal thoughts and behavior in some people. If you have a history of depression or suicidal ideation, Nayzilam may worsen these conditions. Tell your doctor if you have a history of mental health problems. They’ll talk with you about the safety of using Nayzilam.

Alcohol and Nayzilam

Consuming alcohol while using Nayzilam can increase your risk of serious side effects. These include:

Do not drink alcohol while using Nayzilam without talking with your doctor first.

Pregnancy and breastfeeding with Nayzilam

Nayzilam belongs to a group of drugs called benzodiazepine. Use of these drugs during pregnancy may cause fetal harm.

In benzodiazepine studies, babies born to mothers using these drugs late in pregnancy experienced serious side effects. These included slowed brain activity and neonatal withdrawal syndrome. These conditions indicate your baby is dependent on benzodiazepines. This means their body has gotten used to the drug and needs it to function normally. This is a treatable condition.

If your doctor prescribes Nayzilam for you while you’re pregnant, they’ll monitor your baby closely after it’s born and treat any withdrawal symptoms they have. (Withdrawal symptoms are negative side effects that can occur when a person stops taking a drug their body has become dependent on.)

If you’re pregnant or planning to become pregnant during treatment with Nayzilam, talk with your doctor. They can discuss the risks and benefits of the drug for you and your baby.

Also, if you use Nayzilam while pregnant, consider signing up for The North American Antiepileptic Drug Pregnancy Registry. This registry collects information about Nayzilam’s effects when used during pregnancy. You can learn more about it by calling 888-233-2334 or talking with your doctor.

Nayzilam passes into breastmilk. The drug can cause serious side effects in a baby who’s breastfed. These include poor weight gain, poor feeding, and slowed brain activity.

If you plan to breastfeed your baby while using Nayzilam, talk with your doctor about whether it’s safe. If you do breastfeed while using Nayzilam, your baby should be monitored for serious side effects such as excessive sleepiness after breastfeeding.

Nayzilam (midazolam) belongs to a group of drugs called benzodiazepines. It has a boxed warning about the risk of misuse and addiction. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). It alerts doctors and patients about side effects that may be dangerous.

With misuse, a drug is used differently than how it was prescribed. (This may mean using it more often, at a higher dose, or for a different reason than directed by your doctor.) Misuse can lead to addiction, in which a drug is used even if it’s causing harmful effects.

Misusing Nayzilam can cause serious side effects including overdose, breathing difficulties, coma, and in rare cases, death.

Always use Nayzilam exactly as your doctor prescribes. And be sure to store it in a safe manner to help avoid other people misusing it.

As with most drugs, Nayzilam can cause side effects. Most are mild but in rare cases Nayzilam can cause serious side effects. If you have questions about side effects of this medication, talk with your doctor.

Examples of questions to help get you started include:

  • Can Nayzilam cause weight gain?
  • Will taking two doses of Nayzilam increase my risk of drug dependence?
  • Is my risk of side effects higher if I’m taking other medications for my condition?

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Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.