Duloxetine

(duh-lok-suh-teen)

Trade/other name(s): Cymbalta, duloxetine hydrochloride

Why would this drug be used?

Duloxetine is a type of antidepressant known as a serotonin and norepinephrine reuptake inhibitor (SNRI). It is used to help treat depression, anxiety, and some types of chronic pain. Doctors may prescribe it for other reasons as well.

How does this drug work?

Duloxetine seems to work by raising levels of serotonin and norepinephrine, key chemicals in the brain.

Before taking this medicine

Tell your doctor…

• If you are allergic to any medicines, dyes, additives, or foods.
• If you have ever thought of or attempted suicide. Treatment with an antidepressant may raise the risk of suicidal thoughts, especially during the first few months of treatment.
• If you drink alcohol or are taking any type of sedative. This drug could possibly increase their effects on the nervous system, which in some cases could be dangerous. Heavy alcohol use can damage the liver, and duloxetine could add to this effect.
• If you ever had high blood pressure or any type of heart disease. This drug may raise blood pressure. Your doctor may want to monitor you closely during treatment.
• If you have ever had liver disease (including hepatitis or cirrhosis). This drug is cleared from the body mainly by the liver. It may also affect the liver. Reduced liver function may result in more drug than expected staying in the body, which could lead to unwanted side effects. This drug is not recommended in people who have reduced liver function.
• If you have severe kidney disease, such as requiring dialysis. Reduced kidney function may result in more drug than expected staying in the body, which could lead to unwanted side effects. This drug is not recommended in people who have severely reduced kidney function.
• If you have ever had glaucoma, seizures, or bipolar disorder (manic depressive illness). This drug could make these conditions worse.
• If you have any other medical conditions such as lung disease, congestive heart failure, diabetes, gout, or infections. You may need closer monitoring of these conditions while being treated.
• If you have taken monoamine oxidase inhibitors (such as isocarboxazid, phenelzine, selegiline, and tranylcypromine) within the past 2 weeks. Duloxetine may raise the blood pressure and body temperature, and cause seizures, coma, and even death.
• If you are pregnant, trying to get pregnant, or if there is any chance of pregnancy. This drug might cause problems if taken at the time of conception or during pregnancy. It is important to check with your doctor about whether birth control should be used with this medicine. In some women who have taken this drug in the weeks before delivery, babies have required longer hospital stays due to problems that may have been related to the drug. Women who are pregnant should discuss this with their doctor before starting to take duloxetine.
• If you are breast-feeding. This drug may pass into breast milk and affect the baby. Talk with your doctor about the possible risks of breast-feeding while taking this drug.
• About any other prescription or over-the-counter medicines you are taking, including vitamins and herbs. In fact, keeping a written list of each of these medicines (including the doses of each and when you take them) with you in case of emergency may help prevent complications if you get sick.

Interactions with other drugs

Duloxetine may interact with several other drugs and dietary supplements.

Antidepressants known as monoamine oxidase inhibitors (MAOIs) such as phenelzine (Nardil), tranylcypromine (Parnate), isocarboxazid (Marplan), or selegiline (Emsam) may raise the risk of serious side effects and should not be taken within 2 weeks of taking duloxetine. The antibiotic linezolid (Zyvox), which is given in the vein, also acts as an MAOI and can interact in a harmful way with duloxetine.

Duloxetine may raise the risk of abnormal bleeding. This risk may be increased further if you are taking aspirin or aspirin-containing medicines, non-steroidal anti-inflammatory drugs such as ibuprofen or naproxen, warfarin (Coumadin), or vitamin E.

Thioridazine (Mellaril) should not be taken with duloxetine or within 5 days after duloxetine has been stopped. Interactions between these drugs could affect the heart rhythm.

Tryptophan supplements and St. John's wort are not recommended for use while taking duloxetine.

Drugs that are used to treat migraine or cluster headaches (triptans, such as those listed below) can cause an increased risk of serious side effects (see serotonin syndrome information in "Precautions" section) if taken with duloxetine:

• sumatriptan (Imitrex)
• rizatriptan (Maxalt)
• naratriptan (Amerge)
• eletriptan (Relpax)
• frovatriptan (Frova)
• almotriptan (Axert)
• zolmitriptan (Zomig)

Other drugs or dietary supplements that could possibly interact with duloxetine include:

• sedatives, anxiety medicines, antihistamines, or alcohol
• other antidepressants (amitriptyline, desipramine, imipramine, nortriptyline, fluoxetine, paroxetine, fluvoxamine)
• quinolone antibiotics (such as ciprofloxacin, enoxacin)
• antipsychotic drugs such as haloperidol (Haldol), risperidone (Risperdal), and clozapine (Clozaril)
• heart rhythm drugs (propafenone, flecainide, encainide, quinidine)
• cimetidine (Tagamet)
• sibutramine (Meridia)

There may be other interactions not listed above. Check with your doctor, nurse, or pharmacist about all of your medicines, herbs, and supplements.

Interactions with foods

Because duloxetine and alcohol could interact to cause liver injury, this drug is not recommended in people with heavy alcohol use. No other serious interactions with foods are known at this time. Check with your doctor, nurse, or pharmacist about whether some foods may be a problem.

Tell all the doctors, dentists, nurses, and pharmacists you visit that you are taking this drug.

How is this drug taken or given?

Duloxetine is taken by mouth as a long-acting capsule, once or twice a day. It should be swallowed whole (not opened, chewed, crushed, or broken up). It can be taken with or without food.

The dose and schedule depend on a number of factors, including the reason you are taking it, your kidney function, and how well you tolerate the drug. Lower doses may be recommended in those with kidney problems. (Duloxetine is not recommended for people with reduced liver function or severely reduced kidney function.) Do not change the dose or stop taking this drug without first speaking to your doctor or nurse. Talk to your doctor before starting any new medicines.

Keep the medicine in a tightly closed container and out of the reach of children or pets.

Precautions

This drug can interact with several other medicines and should be used cautiously in people with a number of different medical conditions. See the “Before Taking This Medicine” section of this document for more detailed information.

This drug may make you feel drowsy when you first start taking it or if the dose is increased. Do not drive or operate heavy machinery until you know how the drug affects you. Use caution if taking cold or allergy medicines, sedatives, anxiety medicines, or sleeping pills or if consuming alcohol while taking this medicine. Talk to your doctor or nurse if you feel too drowsy or it does not go away.

As with other antidepressants, this drug may raise the risk of suicidal thoughts and actions, mostly in people under age 25. This is more common during the first few months of treatment. If you notice any strange or unusual thoughts or behavior, such as irritability, sleep problems, aggressiveness, restlessness, panic attacks, or thoughts of suicide while on this medicine, call your doctor. Tell family members, loved ones, and caregivers that you are taking this drug, so that they can help you if they notice behavior changes.

This medicine may take 2 weeks or longer to take effect. Do not stop taking this drug without first speaking to your doctor or nurse. If you are going to stop taking this drug, it should usually be tapered down over the course of several weeks, as directed by your doctor. Suddenly stopping the drug can cause anxiety, dizziness, irritability, headache, insomnia, and confusion in some people.

This drug may raise your blood pressure. If you have or have had high blood pressure or any type of heart disease, talk to your doctor about this. Your doctor will likely want to check your blood pressure during your treatment. Tell your doctor right away if notice any possible symptoms of high blood pressure, including a severe headache, chest pain, or feeling dizzy or light-headed.

Some people may have their blood pressure drop each time they sit up or stand, which can make a person feel dizzy and faint. This is more likely to happen in the first week of treatment or after an increase in dosage, but it can happen any time during treatment. It can sometimes cause fainting, with falls and injuries. Be sure you can steady yourself when standing. Let your doctor know right away if you have dizziness.

Duloxetine should be used with caution if you have a history of glaucoma, seizures, or bipolar disorder (manic depression). This drug could make these conditions worse.

This drug is not recommended in people who have severely reduced kidney function, including those who need dialysis. Reduced kidney function may result in more drug than expected staying in the body, which could lead to unwanted side effects.

This drug is not recommended in people who have liver disease (including hepatitis or cirrhosis). This drug is cleared from the body mainly by the liver. Reduced liver function could result in more drug than expected staying in the body, which could lead to unwanted side effects.

Duloxetine may also affect liver function. Your doctor will likely check your liver function with blood tests on a regular basis. The drug may need to be stopped if these tests become abnormal. Tell your doctor right away if you notice yellowing of the eyes or skin, abdominal pain, or bloating.

Older people may have low levels of sodium in the blood while on this drug. This is usually found only on blood tests, but if severe, may cause sluggishness, unsteadiness, confusion, muscle twitching, seizures, and coma.

This drug can rarely cause a problem called serotonin syndrome, with symptoms such as nausea, vomiting, diarrhea, headache, restlessness, and confusion. It can also cause bleeding, easy bruising, and trouble walking. This syndrome can become life-threatening if not treated quickly. If you have symptoms like these, call your doctor right away.

Rarely, serious rashes have been reported, some of which can become life-threatening. If you notice any rash, blisters, peeling skin, or sores in your mouth while on duloxetine, call your doctor or seek medical help right away.

Possible side effects

You will probably not have most of the following side effects, but if you have any, talk to your doctor or nurse. They can help you understand these side effects and cope with them.

Common

• nausea
• feeling drowsy*

Less common

• trouble sleeping
• headache
• dry mouth
• feeling tired or weak
• feeling dizzy or faint*
• sweating
• constipation
• diarrhea
• upset stomach
• vomiting
• trembling
• loss of appetite
• less interest in sex
• problems with ejaculation (men)
• impotence (men)
• decreased ability to reach orgasm (women)
• feeling restless or nervous
• high blood pressure*
• abnormal blood tests which suggest that the drug is affecting the liver*

Rare

• blurred vision
• hot flashes
• increased heart rate
• weight loss
• liver failure*
• easy bleeding or bruising
• suicidal thoughts or actions*
• serious rash*
• problems passing urine (urinary retention)
• higher blood sugar in diabetics
• low sodium levels in the blood*
• seizures
• death due to liver failure or other causes

*See "Precautions" section for more detailed information.

There are some other side effects not listed above that can also occur in some patients. Tell your doctor or nurse if you develop these or any other problems.

FDA approval

Yes – first approved in 2004.

Disclaimer: This information does not cover all possible uses, actions, precautions, side effects, or interactions. It is not intended as medical advice, and should not be relied upon as a substitute for talking with your doctor, who is familiar with your medical needs.