Dealing with anxiety disorders or major depression can feel frustrating, even overwhelming without the right treatment. For many people, taking medication is a significant step toward improvement in mental health.

One common medication used to treat forms of anxiety and depression is Duloxetine (often known by the brand name Cymbalta). On this page, we’ve outlined some important information about the drug.

What is Duloxetine?

What is Duloxetine? How does it work?

Duloxetine is an antidepressant used to treat conditions such as major depressive disorder and generalized anxiety disorder. Also called Cymbalta, it may sometimes be used to treat nerve pain such as fibromyalgia and stress urinary incontinence in women.

Duloxetine belongs to a class of antidepressants called serotonin and norepinephrine reuptake inhibitors (SNRIs). SNRIs like Duloxetine work by increasing the concentration of serotonin and norepinephrine in the brain. Serotonin and norepinephrine are neurotransmitters that help regulate mood, and changing their levels in the brain can affect how you feel. 

How should Duloxetine be used?

Duloxetine is taken through oral dosage via delayed-release capsules. Swallow the capsule whole; do not chew or crush the capsule, and do not open the capsule and sprinkle its contents on food. The dosage will differ based on the patient’s condition. 

Your doctor will likely start you on a lower dose and increase it over time to minimize initial side effects. It may take several weeks before you notice the full effects of duloxetine, but do not stop taking the medication or change doses without first consulting your doctor. 

If you take duloxetine and have been feeling better for several months, your doctor might suggest coming off of the medication, though a longer course of treatment might be appropriate. This process often involves gradually reducing the dose over several weeks (sometimes longer, if you have been taking the medication for a long time). This process—also called “tapering”—helps reduce any negative reactions associated with coming off of duloxetine too quickly. 

What are some possible side effects?

Some common side effects of duloxetine include:

• Nausea, vomiting, constipation or diarrhea 
• Decreased appetite
• Sweating or night sweats 
• Tiredness or weakness

Some serious (but uncommon) side effects include:

• Unusual bleeding or bruising
• Swelling of the abdomen
• Difficulty breathing or swallowing 
• Flu-like symptoms 

Call 911 or seek emergency care if you notice any severe side effects. 

Why do these side effects occur? 

Any medication can potentially lead to side effects, and a person’s likelihood of having side effects depends on many factors, including age, lifestyle, and the type of medication itself. Side effects may occur because drugs often have broad or poorly targeted effects, or the drug target itself may have many downstream effects on the body. For example, though duloxetine targets serotonin and norepinephrine to help improve mood, there are other areas affected by these neurotransmitters, and unusual changes in serotonin and norepinephrine levels can lead to side effects. 

Many non-serious side effects of mental health medications like duloxetine go away after a few weeks as your body gets used to the medication. However, if a side effect persists, is intolerable, or severely hinders your ability to go about your daily life, talk to your doctor, because this might be a sign of a deeper problem. 

How do your genes relate to duloxetine? 

Genetics can affect your body’s response to medication. Research suggests that duloxetine is metabolized by the CYP1A2 and CYP2D6 enzymes. This means that some people with a certain variation in either gene might be slow metabolizers for duloxetine. Being a slow metabolizer means your body will break down the medication more slowly than others, which means the drug sticks around for longer than intended and may lead to side effects. For slow metabolizers, a doctor might opt to prescribe a different medication or prescribe a lower dosage. 

One way to find out how your body might process duloxetine is by taking a genetic test to determine what genetic variations you have and how they affect medication metabolization. Your DNA can help your doctor rule out less suitable medications and make more informed decisions so that you can get better, faster.

Special Precautions

• Do not take duloxetine with monoamine oxidase inhibitors (MAOIs); it may cause confusion, agitation, restlessness, stomach or intestinal symptoms, sudden high body temperature, extremely high blood pressure, or severe convulsions. Ask your doctor if you are not sure if you have taken a monoamine oxidase inhibitor. 
• Duloxetine may increase your risk for bleeding problems. Make sure your doctor knows if you are also taking other medicines that thin the blood, such as aspirin, NSAID pain medicines or warfarin.
• Serious skin reactions can occur during treatment with duloxetine. Check with your doctor if you have blistering, peeling, or loosening of the skin, chills, cough, diarrhea, itching, joint or muscle pain, red irritated eyes, red skin lesions, often with a purple center, sore throat, sores, ulcers, or white spots in the mouth or on the lips, or unusual tiredness or weakness while you are using this medicine.

If you show signs of an allergic reaction to duloxetine (hives, difficulty breathing, rash, swelling), call 911 or go to the nearest emergency department.

Some medications, vitamins, and herbs may interfere with how duloxetine] works. Make sure to tell your doctor about all other medications you are taking before starting duloxetine to avoid negative interactions. For full details, see the FDA’s full list of precautions. 

Looking to find the right medication for your mental health? Join Prairie today to connect to expert providers and affordable medication options.