Medically Reviewed by Harshi Dhingra, M.D.

Last Reviewed: Jun 22, 2022


What are the risks of taking Cymbalta (duloxetine)?

Cymbalta can cause serious health problems, especially in certain high-risk groups. Some of the serious risks of this medication include

  • Suicidal Thinking: In a small number of children, adolescents, and young adults under the age of 24 years, duloxetine (Cymbalta) can increase the risk of suicidal thoughts and behavior. The risk is higher in people who take other antidepressants to treat depression. Unusual changes in mental health can occur even in people over the age of 24 and people who do not have mental illness. Be vigilant for symptoms like new or worsening depression, thoughts or behaviors of killing or harming yourself, extreme worry, agitation, panic attacks, or sleep problems. Call your doctor immediately if they occur.
  • Serotonin syndrome: Very rarely, SNRIs like Cymbalta can cause a potentially life-threatening increase in serotonin levels in the brain. The risk is higher in individuals who take other drugs that affect serotonin, such as other antidepressants, Lexapro, lithium, Dilaudid, and St John’s Wort. Symptoms of serotonin syndrome include confusion, fever, sweating, muscle stiffness, and fast heart rate. Seek professional medical attention right away if you experience these signs and symptoms. 

  • Bleeding risk: In some people, duloxetine (Cymbalta) can increase the risk of bleeding. The risk is higher when a person is taking medications such as blood thinners or NSAIDs (Advil). Tell your doctor if you notice any unusual bleeding, bruises, dark stools, or pink or red urine.
  • Low sodium: Cymbalta can cause low blood sodium levels. Please contact your doctor immediately if you experience confusion, memory difficulties, problems with concentration, headache, or weakness. This risk is higher in patients who take diuretics (water pills) or become dehydrated.
  • Mania: People with bipolar disorder have alternating periods of depression and mania. If a person with this condition initially presents with depression and is treated with an antidepressant like Cymbalta, it can bring on a manic episode. Talk to your health care provider right away if you notice unusual behaviors or symptoms like overactivity, euphoria, and delusions
  • Withdrawal: Abruptly stopping Cymbalta can lead to withdrawal symptoms such as dizziness, agitation, nausea, anxiety, flu-like symptoms, and sleeping difficulties. These symptoms typically appear within 3 days of stopping the medication. Ensure proper medical care is provided and ask your doctor how to stop Cymbalta gradually.
  • Liver Damage: Rarely, Cymbalta can cause liver damage. Call your doctor immediately or go to the emergency room if you experience symptoms such as jaundice (yellowing of the skin or eyes), dark-colored stools, stomach pain, abdominal swelling, nausea, vomiting. 
  • Blood Pressure Changes: Cymbalta can cause low blood pressure and increase the risk of fainting and falls. The risk is higher in the first week of treatment when the dose is increased and at higher doses of more than 60 mg per day. To prevent this from happening, you should get up slowly from a sitting or lying position. Cymbalta can also cause an increase in blood pressure. Therefore, your physician may ask you to monitor your blood pressure regularly. 

Your doctor or pharmacist may prescribe other treatments for depression, anxiety, chronic pain, neuropathic pain, or fibromyalgia if you are at a high risk of complications from Cymbalta. 

What should I tell my doctor before starting Cymbalta (duloxetine)?

Tell your health care professional about all your medical conditions. Cymbalta may not be suitable for people with certain medical conditions like heart disease, high blood pressure, seizures, liver or kidney disease, or diabetes. Also, tell your doctor if you have a history of mental health problems, such as bipolar disorder or suicide attempts.

Also, tell your doctor about all your medications, including prescription drugs, over-the-counter medications, vitamins, dietary supplements, and herbal products. This can help avoid serious drug interactions.

Tell your doctor if you have an allergy to duloxetine, any ingredients in the Cymbalta capsules, or any other medications. Your local pharmacy can provide you with a list of ingredients.

Tell your doctor if you are pregnant, breastfeeding, or plan to become pregnant. Cymbalta can cause problems in a newborn baby, especially if used during the last few months of pregnancy.

Drinking alcohol while on Cymbalta can increase your risk of serious side effects. Talk to your doctor about the safe use of alcohol while on this medicine.

Talk to your doctor about checking your blood pressure and getting an eye exam before starting Cymbalta.

What precautions should I take while on Cymbalta (duloxetine)?

Keep all your healthcare appointments and see your doctor at regular intervals for proper medical care. 

A small number of children, teenagers, and young adults (under the age of 24) can experience unexpected mental health changes and suicidality on Cymbalta. Please call your healthcare providers immediately if you notice any emotional problems or behavioral changes in yourself or a family member during Cymbalta treatment. 

Cymbalta can make you dizzy, lightheaded, or drowsy. Do not drive, operate heavy machinery, or do anything that requires focus before knowing how this medication affects you.

Duloxetine (Cymbalta) can cause a decrease in blood pressure and make you dizzy or lightheaded when you rise from a lying or sitting position. Get up slowly, especially in the first week of treatment and after dose changes.

Cymbalta can also cause an increase in blood pressure. Have your blood pressure checked before starting treatment, and keep an eye on it while taking this medicine.

Tell your doctor if you become pregnant while taking Cymbalta. This medicine should be used with caution in women who are pregnant or breastfeeding.

If you are having surgery, including dental surgery, tell your doctor or dentist that you are on duloxetine (Cymbalta).

Rarely, Cymbalta can cause fluid build-up and increased pressure in the eye (a condition known as closed-angle glaucoma). Call your doctor immediately if you have eye pain, eye swelling, or vision changes.

What are Cymbalta (duloxetine) interactions?

Taking Cymbalta with some other medications can affect how it works. Drug interactions can also increase the risk of serious side effects. Your healthcare provider may choose a different medication for you, change the dose or frequency of one or both medicines, or monitor you carefully for side effects if there are known interactions between Cymbalta and some of your other medications. 

Taking Cymbalta is not recommended if you have taken a monoamine oxidase inhibitor (MAO inhibitor) within the past 14 days. Examples of MAO inhibitors are linezolid (Zyvox), tranylcypromine (Parnate), isocarboxazid (Marplan), phenelzine (Nardil), selegiline (Eldepryl, Zelapar, Emsam), and methylene blue. 

There can be interactions between Cymbalta and medicines such as:

  • blood thinners
  • other antidepressants
  • antihistamines
  • NSAIDs and aspirin
  • diuretics (water pills)
  • cimetidine (Tagamet)
  • fentanyl
  • certain medications for irregular heartbeat
  • certain medications for anxiety
  • certain antibiotics

This list does not describe all possible Cymbalta interactions. Give your health care provider a complete list of your medications, including prescription and non-prescription drugs, vitamins and supplements, and herbal remedies. Also, tell your health care provider if you smoke, drink alcohol, or use recreational drugs because some of these substances can cause serious health complications when used with prescription drugs.