Cymbalta vs Effexor: Differences and Side Effects

Approximately 16 million American adults are living with major depression and around 7 million American adults experience generalized anxiety disorder, according to the Anxiety and Depression Association of America. 

With so many people experiencing these and other mental health conditions, prescription medications have become an effective part of treatment.

Cymbalta (duloxetine) and Effexor (venlafaxine HCl) are two prescription drugs that can be used for the treatment of depression and anxiety. 

Although the drugs are very similar in many ways, there are also a number of important differences and side effects to consider when comparing Cymbalta vs. Effexor. 

Drug Class

Effexor and Cymbalta both belong to a class of drugs called serotonin-norepinephrine reuptake inhibitors (SNRIs).

These drugs help to stabilize mood in those with depression.

They work by increasing the levels of certain neurotransmitters in the brain called serotonin and norepinephrine.

Other SNRIs include desvenlafaxine (Pristiq) and milnacipran (Savella). 

They differ from selective serotonin reuptake inhibitors (SSRIs) like fluoxetine (Prozac or Oxactin), escitalopram (Lexapro), sertraline (Zoloft), and paroxetine (Seroxat), as SSRIs only block serotonin reuptake. 

A third drug class, monoamine oxidase inhibitors (MAOIs) are also used to treat depression, and they remove serotonin, norepinephrine, and dopamine from the brain. There are also tricyclic antidepressants like nortriptyline (Pamelor) and imipramine (Tofranil).

Conditions Treated

Major Depressive Disorder

Cymbalta and Effexor are both used for treating major depressive disorder.

Also known as clinical depression, major depressive disorder is characterized by intense sadness that has occurred for a period of at least two weeks. 

Clinical depression is classified as a mental health disorder. Symptoms of depression can substantially impact a person’s quality of life.

Many patients with clinical depression also find that they lose interest in activities that they previously enjoyed or struggle to complete daily tasks, such as cleaning or working. It is also common for patients to have suicidal thoughts and tendencies. 

Symptoms of major depressive disorder include:

• Feeling sad or empty
• Difficulty concentrating
• Feelings of worthlessness, guilt, hopelessness, or helplessness
• Sleeping and eating more or less than usual
• Lost of interest in activities that were previously enjoyed
• Low energy levels
• Suicidal thoughts or behaviors

Generalized Anxiety Disorder

Cymbalta and Effexor are also both approved for the treatment of generalized anxiety disorder, or GAD.

People with generalized anxiety disorder experience a constant feeling of anxiety that lasts for at least six months and interferes with a person’s daily activities and quality of life. 

Symptoms of generalized anxiety disorder can include restlessness, difficulty concentrating, persistent worrying, difficulty falling asleep, nervousness, sweating, and nausea. 

Other Conditions

In addition to major depressive disorder and generalized anxiety disorder, Cymbalta is also used for the treatment of fibromyalgia and diabetic neuropathy.  

Fibromyalgia is a chronic medical condition that causes widespread musculoskeletal pain with no obvious cause, injury, or illness.

Everyone with fibromyalgia experiences symptoms of fibromyalgia differently, but it is common for patients to experience symptoms that include fatigue, memory issues, tension headaches, sleep problems, and mood changes. 

Patients with diabetes whose bodies are unable to manage their blood sugar levels may experience diabetic neuropathy.

People with diabetic neuropathy experience nerve pain that can occur throughout the body, but it is most often felt in the legs and feet.

Symptoms associated with diabetic neuropathy include tingling and numbness in the legs and feet, neuropathic pain, cramps, stomach pain, weakness, and increased sensitivity to touch. 

Cymbalta can also be used to treat depressive episodes in those suffering from bipolar disorder.

Panic Disorder

In addition to major depressive disorder and generalized anxiety disorder, Effexor is also used to treat panic disorder.

Panic disorder is a type of anxiety disorder that is characterized by recurrent panic attacks, which can suddenly manifest as intense fear and anxiety without an obvious cause. 

People who have panic attacks may feel like they are having a heart attack. While many people will experience one or two panic attacks over the course of their lifetime, people with panic disorder experience panic attacks repeatedly. 

Symptoms of panic attacks include: 

• Rapid, pounding heart rate
• Trembling or shaking
• Feeling detached from reality
• Nausea
• Sense of impending doom or danger
• Dizziness, lightheadedness or faintness
• Headache
• Fear of loss of control 
• Chest pain
• Sweating
• Shortness of breath or tightness in your throat
• Numbness or tingling sensation
• Hot flashes
• Abdominal cramping

Side Effects

Effexor and Cymbalta may cause similar side effects. However, Effexor is known to cause more problems with sexual dysfunction than Cymbalta.

However, everyone reacts to medications differently, so some patients may find that they feel better taking Cymbalta than Effexor and vice versa.

Effexor

Common side effects of Effexor include:

• Fatigue
• Unusual dreams
• Sexual problems
• Increased heart rate
• Loss of appetite
• Constipation
• Diarrhea
• Nausea
• Vomiting
• Dry mouth
• Trouble sleeping
• Yawning
• Tremors
• Dizziness
• Blurred vision
• Sweating
• Headache

Less common but potentially serious side effects of Effexor include:

• Suicidal thoughts
• Serotonin syndrome
• Blood pressure changes
• Enlarged pupils
• Anxiety
• Insomnia
• Appetite or weight changes
• Manic/hypomanic episodes
• Low sodium levels
• Seizures
• Abnormal bleeding
• High cholesterol levels
• Lung disease and pneumonia
• Allergic reactions

Cymbalta

Possible side effects associated with Cymbalta generally fall into two categories: common and less common. Common side effects associated with Cymbalta include:

• Nausea
• Dry mouth
• Drowsiness
• Constipation
• Decreased appetite
• Increased sweating
• Vomiting
• Diarrhea

Less common adverse effects that may occur in long-term users of Cymbalta include:

• Liver problems
• Orthostatic hypotension
• Serotonin syndrome
• Abnormal bleeding
• Stevens-Johnson syndrome
• Manic/hypomanic episodes
• Glaucoma
• Seizures
• Increased blood pressure
• Low sodium levels

If you experience any of these side effects, or side effects persist or worsen, seek medical advice from your healthcare provider.

This may not be a complete list of side effects. Upon discontinuation of Cymbalta or Effexor, you may find yourself suffering from withdrawal symptoms.

Additionally, you should ask your prescribing doctor if Cymbalta or Effexor may have negative drug interactions with any of your current medications.

Effectiveness

Effexor and Cymbalta have both been shown to be effective antidepressants; however, Effexor may be a preferred option for the short-term treatment of major depressive disorder. 

There are no long-term differences in the effectiveness of Effexor and Cymbalta for the treatment of major depressive disorder and generalized anxiety disorder; in fact, both medications are similar in efficacy and tolerability. Some patients may find that one medication works better than the other based on their individual response to the medication.

No matter which medication your doctor prescribes, both Effexor and Cymbalta may take up to several weeks to start working. It usually takes around 2 to 6 weeks for an SNRI to start producing maximum benefits.

Summary

Cymbalta and Effexor are both effective treatment options for patients experiencing major depressive disorder or generalized anxiety disorder. 

Patients who need a short term-treatment option may find that Effexor is more effective in helping manage their symptoms, and Effexor comes in an extended-release form called Effexor XR, another treatment option to consider. However, Effexor may cause more sexual side effects than Cymbalta.  

Both medications are available in both generic and brand-name forms by prescription and are usually covered by commercial health insurance in their generic form. 

Regardless of which medication and which dosing your doctor prescribes, you can save on the cost of your prescription with a pharmacy discount card from Pharmacists.org.

References, Studies and Sources:
https://www.ncbi.nlm.nih.gov/books/NBK81817/ 
https://www.webmd.com/drugs/2/drug-1836/effexor-oral/details 
https://www.healthline.com/health/clinical-depression 
https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(17)32802-7/fulltext#seccestitle140 
https://www.webmd.com/drugs/2/drug-91491/cymbalta-oral/details 
https://adaa.org/about-adaa/press-room/facts-statistics