All About Duloxetine Oral Capsule

What are duloxetine’s side effects?

Like most drugs, duloxetine oral capsules may cause mild or serious side effects. Some of the more common side effects that duloxetine oral capsules may cause are listed here. This section does not include all possible side effects.

Keep in mind that side effects of a drug can depend on:

• your age
• other health conditions you have
• other medications you may be taking

Your doctor or pharmacist can tell you more about the potential side effects of duloxetine oral capsules. They can also suggest ways to help reduce side effects.

Mild side effects

Here’s a short list of some of the mild side effects that duloxetine oral capsules can cause. To learn about other mild side effects, talk with your doctor or pharmacist, or read the drug’s prescribing information.

Mild side effects of duloxetine oral capsules that have been reported include:

• constipation
• dizziness
• dry mouth
• excessive sweating
• fatigue (low energy)
• feeling drowsy (extremely sleepy)
• headache
• insomnia (difficulty falling asleep or staying asleep)
• loss of appetite
• nausea
• sexual side effects
• weight loss

For more information on sexual side effects and weight loss, see the “Side effect focus” section.

Mild side effects of many drugs may go away within a few days or a couple of weeks. But if they become bothersome, talk with your doctor or pharmacist.

Serious side effects

Serious side effects from duloxetine oral capsules can occur, but they are not common. If you have serious side effects from duloxetine oral capsules, call your doctor right away. But if you think you’re having a medical emergency, you should call 911 or your local emergency number.

Serious side effects of duloxetine oral capsules that have been reported include:

• bleeding or bruising more easily than usual
• eye problems, such as vision changes and pain, redness, or swelling around your eyes
• fainting
• high blood pressure
• liver problems that can lead to liver failure
• mania or hypomania (periods of extremely high energy level and excitement)
• orthostatic hypotension (a sudden drop in blood pressure that happens when you stand up too quickly)
• serotonin syndrome (high levels of serotonin, which is a chemical made by your body’s nerve cells)
• severe skin reaction, such as erythema multiforme and Stevens-Johnson syndrome
• seizures or convulsions (rigid or uncontrolled muscle movements)
• withdrawal symptoms if you suddenly stop taking the drug
• falls
• low sodium level
• boxed warning: increased risk of suicidal thoughts and behaviors
• allergic reaction

For more information on the boxed warning and allergic reaction, see the “Side effect focus” section that follows.

Note: For falls and low sodium levels, the risk of these side effects may be higher in older people compared with younger people. To learn more about how your age affects your risk of side effects from duloxetine oral capsules, talk with your doctor.

Side effect focus

Learn more about some of the side effects duloxetine oral capsules may cause.

Boxed warning

Duloxetine oral capsules have a boxed warning. This is a serious warning from the Food and Drug Administration (FDA) about drug effects that may be dangerous.

Increased risk of suicidal thoughts and behaviors: Duloxetine oral capsules have a boxed warning for suicidal thoughts and behaviors. This risk especially affects children, adolescents, and young adults who take medications such as duloxetine to treat depression.

The risk of this side effect is highest in the following situations:

• in people younger than 24 years of age
• during the first several months after the drug is started
• after any dosage changes

Keep in mind that duloxetine is not used to treat depression in children. But doctors may prescribe the drug to treat anxiety or fibromyalgia in certain children.

You should watch for the following symptoms while you’re taking duloxetine oral capsules:

• new or worsening anxiety
• new or worsening depression
• aggressive or violent behavior
• feelings of agitation, anger, irritability, or restlessness
• thoughts of hurting yourself
• difficulty sleeping

What might help

Tell your doctor right away if you have any unusual changes in behaviors, feelings, moods, or thoughts while you’re taking duloxetine. Your doctor may change your treatment plan or prescribe a drug other than duloxetine for you.

Sexual side effects

You may have sexual side effects while you’re taking duloxetine oral capsules. These side effects were common in males during studies of the drug. Sexual side effects from duloxetine were less common in females during studies.

Sexual side effects that are common in males taking duloxetine include:

• erectile dysfunction (inability to get or keep an erection)
• difficulty having an orgasm
• difficulty feeling sexually satisfied

Keep in mind that conditions such as depression, which this drug is used to treat, can also cause sexual side effects. So it may be hard for you to tell whether these side effects are caused by duloxetine or the condition you’re taking the drug to treat.

Note: The use of binary terms such as “male” and “female” or “men” and “women” in this article reflects the language of the sources we’ve used. Unless otherwise noted, it’s unclear whether the research we reference included participants with expansive gender identities.

What might help

Tell your doctor if you have sexual side effects while you’re taking duloxetine oral capsules. Your doctor can determine whether the side effects are from duloxetine or the condition you’re treating.

Weight loss

You may have weight loss while you’re taking duloxetine oral capsules. In studies of the drug, this was not a common side effect in adults. But it was common in children who took duloxetine to treat depression. (Keep in mind that duloxetine is typically not used to treat depression in children.)

It’s important to note that depression, which duloxetine is used to treat, may cause weight gain. So you may have weight loss after you start taking duloxetine to treat depression. This could be a sign the drug is working to treat your condition.

What might help

If you’re concerned about weight loss while you’re taking duloxetine oral capsules, talk with your doctor. They can suggest healthy ways to manage your weight.

Allergic reaction

Some people may have an allergic reaction to duloxetine oral capsules. Studies of duloxetine did not report allergic reactions as a side effect. But allergic reaction has been reported after the drug became available to prescribe.

Symptoms of a mild allergic reaction can include:

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

A more severe allergic reaction is rare but possible. Symptoms of a severe allergic reaction can include swelling under your skin, typically in your eyelids, lips, hands, or feet. They can also include swelling of your tongue, mouth, or throat, which can cause difficulty breathing.

Call your doctor right away if you have an allergic reaction to duloxetine oral capsules. But if you think you’re having a medical emergency, call 911 or your local emergency number.

What is duloxetine used for?

If you have depression, anxiety, or pain, your doctor may prescribe duloxetine for you. It’s a prescription drug that’s used to treat the following:

• Major depressive disorder (MDD): To treat MDD, doctors may prescribe duloxetine oral capsules for adults. MDD is also called depression. With MDD, you have depression symptoms almost daily for at least 2 weeks. These symptoms can include:
  • inability to concentrate or complete tasks
  • loss of appetite
  • loss of interest in activities you once enjoyed
  • mood changes, such as irritability
  • difficulty sleeping
  • weight gain or weight loss
• Generalized anxiety disorder (GAD): To treat GAD, doctors may prescribe duloxetine oral capsules for adults and children ages 7 years and older. With GAD, you have anxiety symptoms almost daily for at least 6 months. These symptoms can include:
  • restlessness
  • difficulty breathing
  • loss of concentration
  • difficulty falling asleep
  • fatigue (low energy)
  • feelings of worry
• Diabetic neuropathy: To treat diabetic neuropathy, doctors may prescribe duloxetine oral capsules for adults. This condition is a type of nerve pain that happens in people with diabetes. It’s caused by having a high blood sugar level over a long period of time.
• Fibromyalgia: To treat fibromyalgia, doctors may prescribe duloxetine oral capsules for adults and children ages 13 years and older. This condition is a type of muscle and bone pain that also causes other symptoms. Examples of these symptoms include fatigue (low energy), difficulty sleeping, and problems with memory.
• Chronic musculoskeletal pain: To treat chronic (long-lasting) musculoskeletal pain, doctors may prescribe duloxetine oral capsules for adults. This condition is a type of muscle and bone pain that lasts for several months.

Duloxetine belongs to a group of drugs called serotonin-norepinephrine reuptake inhibitors (SNRIs). It works by increasing the levels of brain chemicals called serotonin and norepinephrine. This helps to relieve pain and improve your emotions and mood.

What is the dosage of duloxetine?

Your doctor will recommend the dosage of duloxetine oral capsules that’s right for you. This section discusses commonly used dosages, but always take the dosage your doctor prescribes.

Form and strengths

Duloxetine oral capsule is a delayed-release capsule that you swallow. Delayed release means that the drug is released into your body a certain amount of time after you take the capsule.

Duloxetine oral capsules come in the following strengths:

• 20 milligrams (mg)
• 30 mg
• 40 mg
• 60 mg

Recommended dosages

Your dosage of duloxetine oral capsules will vary depending on the condition you’re using the drug to treat. Your dosage will also be based on:

• your age
• how well the drug is treating your condition
• other health conditions you may have

The following table describes the recommended dosages of duloxetine for the different conditions it treats in adults. (For information on recommended dosages for children, see the next section.) Your doctor may start you on a lower dosage of the drug and then increase the dosage over time until you reach the maintenance (ongoing) dosage that is right for you.

Children’s dosages

The following table describes the recommended dosages of duloxetine for the conditions it treats in children: generalized anxiety disorder and fibromyalgia. Your child’s doctor may start your child on a lower dosage of the drug and then increase the dosage over time to reach the maintenance dosage that is right for your child.

Questions about duloxetine oral capsule’s dosage

Here are some common questions about duloxetine oral capsule’s dosage.

What if I miss a dose of duloxetine oral capsules? If you miss a dose of duloxetine, take your missed dose as soon as you remember. But if it’s almost time for your next dose, skip your missed dose. Then take your next dose at the regular time.

Do not take two doses of duloxetine to make up for a missed dose. Doing so can increase your risk of side effects from the drug. If you are not sure whether to take a dose or skip it, ask your doctor or pharmacist.

Will I need to use duloxetine oral capsules long term? If duloxetine is working for you and is not causing bothersome side effects, you’ll likely use the drug long term. Talk with your doctor about how long you’ll need to take this medication.

How long do duloxetine oral capsules take to work? After you start using duloxetine, it will take several weeks for your symptoms to ease. Talk with your doctor about when you can expect your symptoms to ease.

How is duloxetine taken?

Your doctor will explain how you should take duloxetine oral capsules. They will also explain how much to take and how often. For more information, see the “What is the dosage of duloxetine?” section.

Taking duloxetine oral capsule

You’ll take duloxetine oral capsules by swallowing them whole.

Questions about taking duloxetine oral capsule

Here’s a list of common questions related to taking duloxetine oral capsules.

Can duloxetine oral capsules be chewed, crushed, or split? No, duloxetine oral capsules should not be chewed, crushed, or split. You’ll need to swallow the capsules whole. Do not open the capsules and sprinkle their contents onto food or mix them with liquids.

If you have difficulty swallowing duloxetine capsules whole, talk with your doctor. They may prescribe a different form of duloxetine that you can sprinkle onto food.

Should I take duloxetine oral capsules with food? You can take duloxetine oral capsules with or without food.

What are some frequently asked questions about duloxetine?

Find answers to some commonly asked questions about duloxetine oral capsules.

Does stopping duloxetine cause withdrawal symptoms? If so, how long do withdrawal symptoms last?

Yes, suddenly stopping duloxetine oral capsules can cause withdrawal symptoms.

These symptoms can appear within hours or days of stopping the drug. And they might last for several weeks. In rare cases, withdrawal symptoms from duloxetine may last for several months.

Symptoms of withdrawal from duloxetine can include:

• anxiety
• diarrhea, nausea, or vomiting
• dizziness
• excessive sweating
• fatigue (low energy)
• headache
• insomnia (difficulty falling asleep or staying asleep)
• irritability
• paresthesia (temporary burning, numbness, or prickling sensation in your arms, feet, hands, or legs)

You should not stop taking duloxetine unless your doctor says it’s safe to do so. When it’s time for you to stop taking the drug, your doctor will slowly lower your dosage over time. This helps reduce your risk of withdrawal symptoms.

Can duloxetine cause weight gain?

Weight gain was not a side effect of duloxetine oral capsules reported in studies.

Keep in mind that duloxetine is used to treat depression, which can cause weight gain or weight loss. So weight changes may happen while you’re taking duloxetine. But it could be due to your depression getting better and not because of the drug itself.

If you’re concerned about weight gain while you’re taking duloxetine, talk with your doctor. They can suggest healthy ways to manage your weight.

Is duloxetine a controlled substance? Does it make you feel ‘high’?

No, duloxetine is not a controlled substance. It is not likely that you’ll feel “high” (euphoric) with duloxetine.

Controlled substances are medications that are closely regulated by the government. This is because the medications carry a risk of misuse or physical dependence. (Misuse refers to taking a drug in a way other than how it was prescribed. With dependence, your body gets used to a drug and needs it for you to feel like usual.)

These effects are not known to happen with duloxetine. Your doctor will still monitor you to make sure it’s safe for you to keep taking the drug.

Feeling “high” was not a side effect reported in studies of duloxetine. But feeling high may be a symptom of mania or hypomania. (Mania and hypomania are periods of extremely high energy and excitement.) These are possible side effects of duloxetine.

If you’re concerned about how you’ll feel while taking duloxetine, talk with your doctor. They’ll monitor you closely for symptoms of mania or hypomania.

How does duloxetine work and what is its half-life?

Duloxetine belongs to a group of drugs called serotonin-norepinephrine reuptake inhibitors (SNRIs). It works by increasing levels of brain chemicals called serotonin and norepinephrine. This helps to relieve pain and improve your emotions and mood.

The way a drug works in your body is called its mechanism of action.

A drug’s half-life is the time it takes for the amount of drug in your body to decrease by half. The half-life of duloxetine is about 12 hours. This means it takes about 12 hours for your body to get rid of half of a dose of duloxetine.

Is duloxetine an SNRI, SSRI, or narcotic?

Duloxetine belongs to a group of drugs called serotonin-norepinephrine reuptake inhibitors (SNRIs). The drug is not a selective serotonin reuptake inhibitor (SSRI) or a narcotic.

Like SNRIs, SSRIs are a group of drugs used to treat depression and other mental health conditions. Examples of SSRIs include sertraline (Zoloft) and citalopram (Celexa).

“Narcotic” is a term that’s used to describe opioids. Examples of narcotics include:

• illegal opioids, such as heroin
• prescription opioids, such as fentanyl and oxycodone (Roxicodone)

How does duloxetine compare with alternative drugs such as fluoxetine, venlafaxine, and gabapentin?

Both duloxetine and venlafaxine (Effexor XR) belong to a group of drugs called serotonin-norepinephrine reuptake inhibitors (SNRIs).

Fluoxetine (Prozac) belongs to a group of drugs called selective serotonin reuptake inhibitors (SSRIs).

SNRIs and SSRIs are both used to treat mental health conditions such as depression and anxiety.

Gabapentin (Neurontin) belongs to a group of drugs called gabapentinoids. Both duloxetine and gabapentin are used to treat certain types of nerve pain.

If you have questions about how duloxetine, fluoxetine, venlafaxine, and gabapentin are alike and different, talk with your doctor or pharmacist. They can recommend the treatment option that’s best for your condition.

Does duloxetine have any interactions?

Taking medications, vaccines, foods, and other things with a certain drug can affect how the drug works. These effects are called interactions.

Before taking duloxetine oral capsules, be sure to tell your doctor about all medications you take, including prescription and over-the-counter drugs. Also describe any vitamins, herbs, or supplements you use. Your doctor or pharmacist can tell you about any interactions these items may cause with duloxetine oral capsules.

For information about drug-condition interactions, see “Other warnings” in the “What should be considered before taking duloxetine?” section.

Interactions with drugs or supplements

Duloxetine oral capsule can interact with several types of drugs, including:

• drugs broken down in your body by the enzymes (types of proteins) CYP1A2, CYP2D6, CYP2C9, CYP2C19, and CYP3A, such as:
  • the antibiotic ciprofloxacin (Cipro)
  • the acid reflux drug cimetidine (Tagamet HB)
  • the atypical heart rhythm drug quinidine
• antidepressant drugs other than duloxetine, including:
  • tricyclic antidepressants (TCAs), such as amitriptyline
  • selective serotonin reuptake inhibitors (SSRIs), such as sertraline (Zoloft)
  • selective norepinephrine reuptake inhibitors, such as venlafaxine (Effexor XR)
  • monoamine oxidase inhibitors (MAOIs), such as selegiline (Zelapar)
• migraine drugs called triptans, such as sumatriptan (Imitrex)
• attention deficit hyperactivity (ADHD) drugs called amphetamines
• the following pain medications:
  • tramadol
  • fentanyl
  • nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil) and naproxen (Aleve)
• the asthma drug theophylline
• the mood stabilizer drug lithium (Lithobid)
• the anxiety drug buspirone
• the blood thinner drug warfarin (Jantoven)
• the schizophrenia drug thioridazine

Note that you should not take duloxetine oral capsules if you’re taking an MAOI or thioridazine.

Duloxetine can also interact with the herbal supplements tryptophan and St. John’s wort.

This list does not contain all types of drugs that may interact with duloxetine oral capsules. Your doctor or pharmacist can tell you more about these interactions and any others that may occur with use of duloxetine oral capsules.

What should be considered before taking duloxetine?

Some important things to discuss with your doctor when considering treatment with duloxetine oral capsules include:

• your overall health
• other medications you take
• any medical conditions you may have

These considerations and others are described in more detail here.

Boxed warning

Duloxetine oral capsules have a boxed warning about an increased risk of suicidal thoughts and behaviors. This risk affects children, adolescents, and young adults who take medications such as duloxetine to treat depression.

A boxed warning is a serious warning from the Food and Drug Administration (FDA).

For more information about this warning, see the “What are duloxetine’s side effects?” section.

Other warnings

Duloxetine oral capsules may not be right for you if you have certain medical conditions or other factors that affect your health. Talk with your doctor about your health history before you take them. Factors to consider include those in this list:

• Serotonin syndrome: Duloxetine can cause serotonin syndrome. If you have a history of this syndrome or a condition that increases serotonin sensitivity, such as a certain type of tumor, your risk of this serious side effect is increased. Your doctor can recommend other treatment options.
• Bipolar disorder: Duloxetine may cause mania or hypomania. (These are periods of extremely high energy levels and excitement that may be related to bipolar disorder.) Before taking duloxetine, tell your doctor if you have bipolar disorder. They may prescribe a drug other than duloxetine for you.
• Bleeding problems: Duloxetine oral capsules may increase your risk of bleeding. If you already have bleeding problems, your risk may be even higher. Before taking duloxetine, tell your doctor if you have any bleeding problems.
• Delayed stomach emptying: Duloxetine oral capsules are covered in a coating that protects the drug from your stomach acid. If you have a condition that delays emptying of the contents of your stomach, your body could break down the capsule’s coating. This could make the drug less effective for your condition. Before taking duloxetine, tell your doctor if you have a condition that delays your stomach from emptying.
• Diabetes: Tell your doctor if you have diabetes before you start taking duloxetine. The drug can make it hard for you to manage your blood sugar level. Your doctor may monitor your blood sugar levels more closely than usual if you take duloxetine.
• Glaucoma: Before starting duloxetine, tell your doctor if you have glaucoma. Duloxetine can raise your risk of having a glaucoma attack. This is a sudden worsening of glaucoma that causes blurry vision and severe eye pain. Call 911 or your local emergency number right away if you have these symptoms while you’re taking duloxetine.
• Heart problems: If you have heart problems, such as high blood pressure, tell your doctor before starting duloxetine. This drug may increase your blood pressure. So if you already have high blood pressure or other heart problems, you may not be able to take this drug.
• Liver or kidney problems: If you have liver or kidney problems, your body may have difficulty clearing duloxetine from your system. This could cause duloxetine to build up in your body, increasing your risk of side effects from it. Before you take duloxetine oral capsules, tell your doctor about any liver or kidney problems you have.
• Low sodium level in your blood: Duloxetine can cause a low level of sodium in your blood. If you already have a low sodium level, talk with your doctor before starting duloxetine.
• Seizures or convulsions: Duloxetine may cause seizures or convulsions (rigid or uncontrolled muscle movements). If you already have these conditions before taking the drug, your risk of seizures or convulsions with duloxetine may be even higher. Tell your doctor about any history of seizures or convulsions you may have before you take duloxetine.
• Allergic reaction: If you’ve had an allergic reaction to duloxetine or any of its ingredients, you should not take this drug. Ask your doctor what other medications are better options for you.

Duloxetine and alcohol

You should not drink alcohol while you’re taking duloxetine oral capsules. Doing so can cause liver problems, such as liver failure.

If you drink alcohol, talk with your doctor before starting duloxetine.

Pregnancy and breastfeeding

It may not be safe to take duloxetine oral capsules during pregnancy. Taking the drug during the month before you give birth can increase your risk of severe bleeding after delivery.

Additionally, duloxetine can pass into breast milk. If you’re breastfeeding while taking this drug, monitor the child you’re breastfeeding for these side effects:

• drowsiness
• difficulty feeding
• difficulty gaining weight

Talk with your doctor about the risks and benefits of taking duloxetine while you’re pregnant or breastfeeding.

What should be done in case of overdose?

Do not take more duloxetine oral capsules than your doctor prescribes. Using more than this can lead to serious side effects.

Symptoms of overdose

Symptoms caused by an overdose of duloxetine can include:

• drowsiness
• serotonin syndrome (high levels of serotonin, which is a chemical made by your body’s nerve cells)
• seizures
• fainting
• fast heart rate
• low or high blood pressure
• vomiting

What to do in case you take too much duloxetine

Call your doctor if you think you’ve taken too many duloxetine oral capsules. You can also call 800-222-1222 to reach America’s Poison Centers, or use its online resource. But if you have severe symptoms, immediately call 911 (or your local emergency number) or go to the nearest emergency room.

What does duloxetine cost?

Whether you have health insurance or not, cost may be a factor when you’re considering duloxetine. What you’ll pay for duloxetine may depend on several things, such as your treatment plan and the pharmacy you use.

• Comparing pharmacies: The price of duloxetine may vary depending on which pharmacy you use. As a result, it can help to compare prices across pharmacies to find the lowest cost.
• Drug coupons: You may be able to find drug coupons on prescription discount websites that can reduce the cost of your medication. These coupons cannot be used with insurance copays or benefits. However, the discounted price may be lower than what you would pay through insurance.
• Financial assistance: Some websites provide details about drug assistance programs, ways to make the most of your insurance coverage, and links to savings cards and other services. Two such websites are:
  • Medicine Assistance Tool
  • NeedyMeds