Nefazodone

Introduction

Written by Julz Richterman, PharmD, MBA, BCGP
Medically reviewed by Brittany A. Duke, PharmD, RPh 
Updated on November 13, 2023

Nefazodone (nef AY zoe done) is a generic medication prescribed for treating depression. Nefazodone belongs to a group of drugs called antidepressants.

Boxed warnings

Nefazodone oral tablet has boxed warnings about the risks of serious liver failure, suicidal thoughts and behaviors. Boxed warnings are the most serious warnings from the Food and Drug Administration (FDA).

For details, see the “Interactions and warnings for nefazodone” section.

Common questions about nefazodone

Below you’ll find answers to a few commonly asked questions about nefazodone.

What brand names are available for nefazodone?

Serzone is the brand-name version of nefazodone. But it is no longer available. Nefazodone is only available as a generic medication.

A generic medication is an identical copy of the active drug in a brand-name medication. (An active drug is the ingredient that makes a medication work.) Generic drugs are believed to be as effective and safe as brand-name drugs. And generic drugs typically cost less compared to brand-name drugs.

Speak with your doctor or pharmacist to learn more about the differences between brand-name and generic medications.

How does nefazodone work? And how long does it take to start working?

The mechanism of action (how the drug works) of nefazodone is not known. Studies show that it prevents your brain cells from taking up certain brain chemicals called serotonin and norepinephrine. These chemicals are known as neurotransmitters. They carry signals from one brain cell to the next.

When your brain cells take less serotonin and norepinephrine, more of these chemicals are available to pass the messages further. This ultimately helps to relieve your symptoms of depression.

You may start noticing a difference in mood within 1–2 weeks of taking nefazodone. But usually, it takes several weeks to take full effect.

If you’d like to know more about this, talk with your doctor or pharmacist.

Is nefazodone similar to trazodone?

Yes, nefazodone and trazodone are similar. They are both part of the same group of drugs called antidepressants. They are prescribed to treat depression in adults and work in similar ways. Both are only available as oral tablets.

Both have boxed warnings about suicidal thoughts and behaviors.* Boxed warnings are the most serious warnings from the Food and Drug Administration (FDA). But unlike nefazodone, trazodone does not have boxed warnings for the risk of serious liver failure.

Trazodone can also make you more tired and sleepy than nefazodone. Because of this, it is sometimes prescribed off label to help people sleep. With off-label use, doctors prescribe a drug for a purpose other than what it’s approved for. Studies suggest that it can cause certain types of irregular heartbeats in people with particular heart conditions.

Speak with your doctor or pharmacist to learn more about the differences between nefazodone and trazodone.

* For details about this side effect, see the “Interactions and warnings for nefazodone” section.

Side effects of nefazodone

Nefazodone may cause mild or serious side effects. More common mild side effects of nefazodone and its serious side effects are listed below. This article doesn’t include all possible side effects of the drug. Side effects can vary based on your age, overall health, and any other medications you take.

To learn more about nefazodone’s side effects, ask your doctor or pharmacist. You can also refer to the prescribing information for nefazodone listed in the “Resources” section.

Mild side effects

More common mild side effects reported with some forms of nefazodone are listed below.

This article doesn’t include all possible mild side effects of the drug. To learn more about nefazodone’s side effects based on the form, refer to the prescribing information for nefazodone listed in the “Resources” section.

With many drugs, mild side effects may go away within a few days or a couple of weeks. If the side effects are bothersome, tell your doctor or pharmacist. They may be able to suggest ways to manage them.

Nefazodone oral tablet’s mild side effects include:

• nausea
• dizziness
• difficulty sleeping
• low energy levels or weakness
• mild allergic reaction*

* For details about this side effect, see the “Interactions and warnings for nefazodone” section.

Serious side effects

Serious side effects of nefazodone are listed below.

This article doesn’t include all possible serious side effects of the drug. To learn more about nefazodone’s serious side effects, refer to the prescribing information for nefazodone listed in the “Resources” section.

With many drugs, serious side effects are possible but not common. If you have serious side effects from this drug, call your doctor right away. If you’re having severe symptoms or a medical emergency, call 911 or a local emergency number.

In general, nefazodone’s serious side effects include: 

• a drop in blood pressure when you stand up too quickly
• overactive behavior
• boxed warning(s): risk of serious liver failure and suicidal thoughts and behaviors*
• severe allergic reaction*

* For details about these side effects, see the “Interactions and warnings for nefazodone” section.

Uses of nefazodone

The Food and Drug Administration (FDA) approves prescription drugs such as nefazodone for certain conditions. Approved uses for nefazodone are described below. These uses differ based on the form of nefazodone prescribed.

Use for depression

Doctors may prescribe nefazodone tablets for treating depression. It’s used for this purpose in adults. It’s usually prescribed as a long-term treatment.

Depression is a mood disorder that affects how you feel, think, and behave. Depression can affect you in many different ways, common symptoms include:

• feeling sad or empty
• decreased energy
• easily bothered, irritated, or angry
• difficulty concentrating or making decisions
• under or oversleeping

To receive a diagnosis of depression, your symptoms must be present most of the time for at least 2 weeks.

Depression has several causes, including hormone changes, family history, and medical conditions. But researchers still cannot say with certainty why some people experience depression, and others don’t.

Interactions and warnings for nefazodone

Below, you’ll find information about nefazodone’s possible interactions and warnings.

Interactions of nefazodone

Certain things may affect how a drug works. These include getting vaccines, consuming alcohol or certain foods, or taking the drug with other medications. This effect is called a drug interaction.

Before you take nefazodone, ask your doctor to check for possible interactions. Be sure to tell them about any of the following you take or use:

• prescription or over-the-counter drugs 
• vitamins, herbs, or supplements

To learn about drug-condition interactions, see the “Warnings for nefazodone” section below.

Warnings for nefazodone

Some people should not take nefazodone, and others should take it cautiously.

Boxed warnings

Nefazodone has boxed warnings about the risk of serious liver failure and suicidal thoughts and behaviors. Boxed warnings are the most serious warnings from the Food and Drug Administration (FDA).

To learn more about these warnings, read below. You can also talk with your doctor or pharmacist.

Risk of serious liver failure. With liver failure, you may experience stomach issues, decreased appetite, or general feelings of discomfort. You may also experience yellowing of your skin or whites of your eyes (jaundice). This side effect was rarely reported in studies of nefazodone.

If you experience any of these symptoms, tell your doctor. They’ll likely recommend you to stop taking nefazodone.

Risk of suicidal thoughts and behaviors. Antidepressants, including nefazodone, can increase your risk of suicidal thoughts and behaviors. This side effect was rarely reported in studies of nefazodone. It is seen in children and young adults under the age of 25 years.

Call your doctor if you experience increased agitation, panic attacks, difficulty sleeping, aggressiveness, or loss of impulse control. This may be a sign that your depression is getting worse. This is especially important to monitor within the first 6–8 weeks of starting the medication.

If you experience worsening depression symptoms, or suicidal thoughts or behaviors, tell your doctor. They’ll likely recommend monitoring you closely or possibly changing your medication.

Suicide prevention

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

• Call the 988 Suicide and Crisis Lifeline at 988.
• Text HOME to the Crisis Textline at 741741.
• Not in the United States? Find a helpline in your country with Befrienders Worldwide.
• Call 911 or your local emergency services number if you feel safe to do so.

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.

Other warnings

Nefazodone could cause harm to people with certain health conditions. This effect is called a drug-condition interaction. Other factors can also affect whether nefazodone is a safe option for you.

Ask your doctor about specific warnings for nefazodone, and be sure to tell your doctor about your:

• current health, including any allergies to medications
• past health conditions or surgeries

Allergic reaction

Nefazodone can cause an allergic reaction in some people. Severe allergic reactions are rare but possible.

If you’ve had an allergic reaction to nefazodone or any of its ingredients, your doctor will likely not prescribe nefazodone. They can tell you about medications that are safer options for you.

A mild allergic reaction may cause the following symptoms:

• skin rash
• itchiness
• flushing (temporary warmth, redness, or deepening of skin color)

A severe allergic reaction may cause the following symptoms:

• swelling under your skin, usually in your hands, feet, eyelids, or lips
• swelling of your mouth, throat, or tongue, which can cause breathing problems

If you have an allergic reaction to nefazodone, call your doctor right away. If you have severe symptoms, call 911 or a local emergency number.

Overdose of nefazodone

You should not take more nefazodone than your doctor prescribes. For some drugs, doing so may lead to harmful effects or overdose.

If you think you’ve taken too much nefazodone, call your doctor or pharmacist right away. Or you could call 800-222-1222 to speak with someone at America’s Poison Centers. You can also use its online resource. If you have concerning symptoms, call 911 or a local emergency number immediately. You can also go to the closest emergency room.

Pregnancy or breastfeeding and nefazodone

Information about nefazodone and pregnancy and breastfeeding is described below.

Nefazodone and pregnancy

It’s not known whether nefazodone should be taken during pregnancy. If you’re planning a pregnancy or can become pregnant, talk with your doctor before taking this medication.

Nefazodone and breastfeeding

It’s not known whether nefazodone should be taken while breastfeeding. If you’re breastfeeding or planning to do so, talk with your doctor before taking this medication.

What to ask your doctor

Let your doctor know if you have questions about nefazodone or would like more details about it.

Here’s a list of some possible questions you may want to ask your doctor:

• Is nefazodone safe to take with my other medications?
• What should I do if I miss a dose of nefazodone?
• Can I drink alcohol while taking nefazodone?

Resources

• Food and Drug Administration. (2023). Orange Book: Approved drug products with therapeutic equivalence evaluations. https://www.accessdata.fda.gov/scripts/cder/ob/index.cfm 
• Nefazodone hydrochloride tablet. (2022). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/0bd4c34a-4f43-4c84-8b98-1d074cba97d5/spl-doc
• Trazodone hydrochloride tablet. (2023). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/d27e4473-6f62-ddfe-e053-2a95a90a9a2c/spl-doc?hl=trazodone

Disclaimer: Optum Perks 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.