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Generic name: duloxetinedu-LOX-e-teen ]
Brand names: Cymbalta, Drizalma Sprinkle, Irenka
Drug class: Serotonin-norepinephrine reuptake inhibitors

Medically reviewed by on Oct 23, 2023. Written by Cerner Multum.

What is Irenka?

Irenka is a serotonin and norepinephrine reuptake inhibitor antidepressant (SNRI).

Irenka is used to treat major depressive disorder in adults. This medicine is also used to treat general anxiety disorder in adults and children at least 7 years old.

Irenka is also used in adults to treat diabetic nerve pain or chronic muscle or joint pain (such as low back pain and osteoarthritis pain).

Some brands of duloxetine are also used to treat fibromyalgia (a chronic pain disorder). Drizalma is for treating fibromyalgia only in adults. Cymbalta may be used to treat fibromyalgia in adults and children at least 13 years old.

Irenka may also be used for purposes not listed in this medication guide.

Irenka side effects

Get emergency medical help if you have signs of an allergic reaction (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).

Tell your doctor right away if you have new or sudden changes in mood or behavior, including new or worse depression or anxiety, panic attacks, trouble sleeping, or if you feel impulsive, irritable, agitated, hostile, aggressive, restless, more active or talkative, or have thoughts about suicide or hurting yourself.

Irenka may cause serious side effects. Call your doctor at once if you have:

Seek medical attention right away if you have symptoms of serotonin syndrome, such as: agitation, hallucinations, fever, sweating, shivering, fast heart rate, muscle stiffness, twitching, loss of coordination, nausea, vomiting, or diarrhea.

Common side effects of Irenka may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


People with depression or mental illness may have thoughts about suicide. Some young people may have increased suicidal thoughts when first starting a medicine to treat depression. Tell your doctor right away if you have any sudden changes in mood or behavior, or thoughts about suicide.

Do not stop using Irenka without first asking your doctor.

Before taking this medicine

You should not use Irenka if you are allergic to it.

Do not take Irenka within 5 days before or 14 days after you have used an MAO inhibitor, such as isocarboxazid, linezolid, methylene blue injection, phenelzine, or tranylcypromine. A dangerous drug interaction could occur.

Tell your doctor if you also take stimulant medicine, opioid medicine, herbal products, or medicine for depression, mental illness, Parkinson's disease, migraine headaches, serious infections, or prevention of nausea and vomiting. An interaction with Irenka could cause a serious condition called serotonin syndrome.

Not approved for use by anyone younger than 7 years old.

Tell your doctor if you have ever had:

People with depression or mental illness may have thoughts about suicide. Some young people may have increased suicidal thoughts when first starting a medicine to treat depression. Stay alert to changes in your mood or symptoms. Your family or caregivers should also watch for sudden changes in your behavior.

Taking Irenka during pregnancy could harm the baby, but stopping the medicine may not be safe for you. Do not start or stop Irenka without asking your doctor.

If you are pregnant, your name may be listed on a pregnancy registry to track the effects of duloxetine on the baby.

If you are breastfeeding, tell your doctor if you notice drowsiness, feeding problems, and slow weight gain in the nursing baby.

How should I take Irenka?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

Taking Irenka in higher doses or more often than prescribed will not make it more effective, and may increase side effects.

Swallow the capsule whole and do not crush, chew, break, or open it.

Take with or without food.

Your blood pressure will need to be checked often.

Tell your doctor if you have any changes in sexual function, such as loss of interest in sex, trouble having an orgasm, or (in men) problems with erections or ejaculation. Some sexual problems can be treated.

Your symptoms may not improve for up to 4 weeks.

Do not stop using Irenka suddenly, or you could have unpleasant symptoms (such as agitation, confusion, tingling or electric shock feelings). Ask your doctor before stopping the medicine.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include vomiting, dizziness or drowsiness, seizures, fast heartbeats, fainting, or coma.

What should I avoid while taking Irenka?

Ask your doctor before taking a nonsteroidal anti-inflammatory drug (NSAID) such as aspirin, ibuprofen, naproxen, Advil, Aleve, Motrin, and others. Using an NSAID with Irenka may cause you to bruise or bleed easily.

Avoid driving or hazardous activity until you know how Irenka will affect you. Dizziness or drowsiness can cause falls, accidents, or severe injuries.

Avoid getting up too fast from a sitting or lying position, or you may feel dizzy.

Drinking alcohol may increase your risk of liver damage, especially if you take Drizalma.

What other drugs will affect Irenka?

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.

Many drugs can affect Irenka. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here. Tell your doctor about all other medicines you use.

Popular FAQ

Common antidepressants used for orthopedic pain relief may include SSRIs like fluoxetine (Prozac), paroxetine (Paxil), and sertraline (Zoloft), SNRIs such as duloxetine (Cymbalta), or tricyclic antidepressants (TCAs) like amitriptyline (Elavil) or nortriptyline (Pamelor). Continue reading

Cymbalta is used to treat depression, anxiety, and some pain syndromes. But what are the risks associated with this drug? Do most people who start it realize how hard it may be to stop? Continue reading

Not being able to sleep (also called insomnia) is one of the most common side effects reported by people taking Cymbalta. In some people, this side effect improves after a couple of weeks of taking Cymbalta, but difficulty falling asleep or staying asleep can persist in others. Here are some ways you can improve sleep while taking Cymbalta:

  • Take your dose of Cymbalta in the morning. Cymbalta may be given once a day or twice a day but for those people experiencing insomnia, it should be taken just once a day in the morning
  • Swallow Cymbalta capsules whole; do not crush, chew, or open up the capsules and sprinkle them on food because this may cause Cymbalta to be absorbed more quickly than intended, increasing the risk of side effects such as insomnia...
Continue reading

Slowly stopping Cymbalta treatment over 2 to 4 weeks is the best way to help avoid withdrawal symptoms like dizziness, nausea or headache. Talk with your doctor first if you want to stop treatment. Continue reading

Cymbalta is more likely to cause weight loss early in the first 8 to 9 weeks of treatment, but result in a modest weight gain after 8 months of treatment. In general, these weight changes are minimal and may be due to temporary side effects like nausea or loss of appetite, some of the most common side effects of Cymbalta treatment. Continue reading

It may take up to 6 to 8 weeks for the full effects of Cymbalta to be seen, although some improvement in symptoms, such as sleep, energy, or appetite may show an improvement in 1-2 weeks. Symptoms such as depressed mood and lack of interest in activities may take the full 6-8 weeks to resolve. When Cymbalta is used for pain, it generally improves within two weeks. Continue reading

People have reported feeling electric shock-like sensations or “brain zaps” when starting Cymbalta (duloxetine) treatment, during treatment, and also when discontinuing it. Most report feeling these in the brain although some report them in other parts of the body. They have been described as feeling like a short, low voltage, electric shock. Continue reading

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Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.