Duloxetine

Introduction

Written by Patricia Weiser, PharmD
Medically reviewed by Alex Brewer, PharmD, MBA
Updated on July 28, 2023

Duloxetine (doo LOX e teen) is a generic medication prescribed for certain mental health conditions. It’s also prescribed for certain types of pain. Duloxetine belongs to a group of drugs called serotonin and norepinephrine reuptake inhibitors (SNRIs).

The Food and Drug Administration (FDA) has approved duloxetine to treat:

• major depressive disorder (commonly called depression) in adults
• generalized anxiety disorder in adults and some children
• diabetic peripheral neuropathic pain in adults
• fibromyalgia in adults
• chronic (long lasting) musculoskeletal pain in adults

Boxed warning: Risk of suicidal thoughts and behaviors

Duloxetine has a boxed warning about the risk of suicidal thoughts and behaviors in certain people. Boxed warnings are the most serious warnings from the FDA.

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

Side effects of duloxetine

Duloxetine may cause mild or serious side effects. More common mild side effects of duloxetine 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 duloxetine’s side effects, see this article or ask your doctor or pharmacist. You can also refer to the prescribing information for duloxetine listed in the “Resources” section.

Mild side effects

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

This article doesn’t include all possible mild side effects of the drug. To learn more about duloxetine’s side effects, refer to the prescribing information for duloxetine 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.

Duloxetine delayed-release oral capsule’s mild side effects include:

• nausea
• dry mouth
• constipation
• decreased appetite
• mild allergic reaction*

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

Serious side effects

Serious side effects of duloxetine are listed below.

This article doesn’t include all possible serious side effects of the drug. To learn more about duloxetine’s side effects, refer to the prescribing information for duloxetine 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, duloxetine’s serious side effects include:

• drop in blood pressure when getting up, which may cause falling or fainting
• discontinuation syndrome (symptoms that can occur if you abruptly stop taking duloxetine)
• increased risk of bleeding
• increased blood pressure
• liver-related side effects, including liver failure
• low sodium levels in the blood
• seizures
• serotonin syndrome (too much serotonin in the body), which may be life threatening
• sexual side effects, including loss of sex drive and difficulty having an orgasm
• mania (periods of high energy that interfere with daily life activities)
• boxed warning: risk of suicidal thoughts and behaviors in certain people*
• severe allergic reaction*

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

Uses of duloxetine

The Food and Drug Administration (FDA) approves prescription drugs such as duloxetine for certain conditions. Approved uses for duloxetine are described below.

Use for certain pain, including nerve pain

Doctors may prescribe duloxetine for managing certain types of pain in adults.

With diabetic peripheral neuropathic pain, someone develops nerve damage in their hands or feet. This nerve damage is related to having diabetes. Symptoms may include:

• numbness, pain, or “pins and needles” sensation in the hands or feet
• burning sensation in the feet, particularly at night
• loss of sense of touch
• challenges with coordination and walking

With fibromyalgia, someone experiences pain throughout their body. The pain often varies in severity, location, or sensation over time. Other symptoms of fibromyalgia may include:

• exhaustion
• difficulty paying attention
• digestive issues
• depression

With chronic musculoskeletal pain, someone experiences pain in their muscles or joints. “Chronic” refers to pain that lasts longer than 6 months. Other symptoms include:

• lack of energy
• difficulty sleeping
• stiffness

Duloxetine may be prescribed to help treat these conditions in adults. It’s usually prescribed as a long-term treatment.

Use for certain mental health conditions

Doctors may prescribe duloxetine for treating certain mental health conditions. Specifically, the drug is prescribed to treat:

• major depressive disorder (commonly called depression) in adults
• generalized anxiety disorder in adults and in children ages 7 years or older

Duloxetine is usually prescribed as a long-term treatment.

With depression, someone experiences feelings, such as sadness, that affect their daily life. Symptoms last longer than 2 weeks and may include:

• feeling sad, anxious, or empty
• loss of interest in hobbies or activities once enjoyed
• decreased energy or fatigue
• difficulty with cognition
• issues with sleep, including insomnia (difficulty sleeping) or oversleeping

With generalized anxiety disorder, someone experiences excessive worrying that affects their daily life. Symptoms may include:

• sensations of fear, panic, or doom, which may appear unreasonable to people without the disorder
• challenges with concentration
• nervousness or restlessness

Common questions about duloxetine

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

Is duloxetine a narcotic?

No, duloxetine isn’t a narcotic. The term “narcotic” refers to a group of drugs similar to opium. Narcotics are types of controlled substances. The government has set up special laws to control how these medications are prescribed.

Some narcotic drugs are prescribed to treat severe pain that isn’t eased by other treatments. Examples of these drugs include oxycodone and codeine.

Duloxetine is used to treat certain types of pain, but it’s not a controlled substance. Duloxetine is a serotonin and norepinephrine reuptake inhibitor (SNRI), which is a type of antidepressant.

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

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

How duloxetine works for certain mental health conditions and certain types of pain isn’t fully known. It’s thought to work by balancing two brain chemicals, serotonin and norepinephrine.

Duloxetine takes some time to work. It may take about 2–4 weeks to reach its full effect.

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

Interactions and warnings for duloxetine

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

Interactions of duloxetine

Certain factors 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 duloxetine, 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 (OTC) drugs
• vitamins, herbs, or supplements

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

Warnings for duloxetine

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

Boxed warning: Risk of suicidal thoughts and behaviors

Duloxetine has a boxed warning about the risk of suicidal thoughts and behaviors in certain people. Boxed warnings are the most serious warnings from the Food and Drug Administration (FDA).

Antidepressants, including duloxetine, increase the risk of suicidal thoughts and behaviors in children and young adults. This risk applies to people ages 24 years and younger. The risk is highest during the first few weeks of treatment and after dosage increases.

Tell your doctor right away if you experience symptoms of suicidal thoughts or behaviors. Symptoms may include new or worsening depression and changes in thoughts, behavior, or mood.

To learn more, talk with your doctor or pharmacist.

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

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

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

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

Allergic reaction

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

If you’ve had an allergic reaction to duloxetine or any of its ingredients, your doctor will likely not prescribe duloxetine. 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

Severe, life threatening allergic skin reactions have been reported in people taking duloxetine. These reactions include erythema multiforme and Stevens-Johnson syndrome (SJS). Symptoms include a blistering or peeling skin rash and muscle aches or discomfort. These conditions require immediate treatment in a hospital or emergency room.

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

Overdose of duloxetine

If you take duloxetine oral capsule, you should not take more duloxetine than your doctor prescribes. For some drugs, doing so may lead to harmful effects or overdose.

If you think you’ve taken too much duloxetine, 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 duloxetine

Information about duloxetine and pregnancy and breastfeeding is described below.

Duloxetine and pregnancy

There are risks to taking duloxetine during pregnancy. But there are also risks with having untreated mental health conditions or pain while pregnant. (Keep in mind that duloxetine is used for treating certain mental health conditions and specific types of pain).

If you’re planning a pregnancy or can become pregnant, talk with your doctor about mental health or pain treatment options during pregnancy. Together, you can discuss the risks and benefits of your treatment options and decide whether or not you should take duloxetine during pregnancy.

Duloxetine and breastfeeding

There are risks to taking duloxetine while breastfeeding. But there are also risks with having untreated mental health conditions or pain during this time. (Keep in mind that duloxetine is used for treating certain mental health conditions and specific types of pain).

For instance, in a breastfed child, duloxetine may cause sedation, difficulty feeding, or difficulty gaining weight.

If you’re planning to breastfeed, talk with your doctor about mental health or pain treatment options. Together, you can discuss the risks and benefits of your treatment options and decide whether or not you should take duloxetine during this time. Your doctor may recommend other healthy ways to feed your child.

What to ask your doctor

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

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

• How does duloxetine compare with other drugs available for treating my condition?
• Should I continue taking my other medications with duloxetine?
• What should I do if I miss a dose of duloxetine?

Resources

• Duloxetine delayed-release capsules, for oral use. (2023). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/556d7dd0-0e3d-4f70-9786-e546a43ef539/spl-doc
• Food and Drug Administration. (2023). Orange Book: Approved drug products with therapeutic equivalence evaluations. https://www.accessdata.fda.gov/scripts/cder/ob/index.cfm

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.