Having major depressive disorder (MDD) can feel overwhelming without the right care. For many people with this disorder, taking antidepressants is a significant step in allowing them to improve their mental health.

One medication often used to treat MDD is called desvenlafaxine (often known by the brand names Pristiq or Khedezla). On this page, we’ve outlined some important information about the drug.

What is desvenlafaxine?

What is desvenlafaxine? How does it work?

Desvenlafaxine is an antidepressant approved to treat MDD. It may sometimes be used off-label to treat sudden strong feelings of heat and sweating in women who have experienced menopause, also known as hot flashes. 

Desvenlafaxine belongs to a class of medications called SNRI (serotonin-norepinephrine reuptake inhibitor) antidepressants. This class of medications act by regulating the levels of certain chemicals called neurotransmitters in the brain. SNRI antidepressants prevent the removal of the neurotransmitters serotonin and norepinephrine, thereby increasing their levels in the brain. Both serotonin and norepinephrine affect mood and sense of well-being. Increased levels of these neurotransmitters can help improve how we feel. 

How is desvenlafaxine typically used?

A typical recommended dose for desvenlafaxine is 50mg, taken once daily. However, the prescription may be adjusted depending on what and who is being treated. Doctors sometimes start their patients off on lower doses and increase it over time in order to reduce the risk of adverse side effects. 

If you need to stop taking desvenlafaxine, you must inform your doctor. Stopping this medication suddenly can cause some negative reactions in your body. To prevent this, your doctor will gradually lower your dose over several weeks to prevent any negative reactions associated with coming off of the medication too quickly. Do not stop taking any medication without informing your doctor first. 

What are some possible side effects?

Some common side effects of desvenlafaxine include:

• Constipation
• Dry mouth
• Dizziness
• Loss of appetite
• Sweating

Some serious (but uncommon side effects) include:

• Difficulty swallowing or breathing
• Cough
• Fast heartbeat
• Seizures
• Coordination problems.

Call 911 or seek emergency care if you notice any severe side effects. Click here to see a fuller list of Desvenlafaxine 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.

Desvenlafaxine belongs to a class of drugs that produce an effect by increasing the levels of certain chemicals that help regulate mood in the brain. However, these chemicals are also involved in some other activities of the body e.g. concentration, breathing, sleep, movement, etc. Increasing the levels of these chemicals can also affect some of these other activities thus producing side effects.  

Many non-serious side effects of mental health medications like desvenlafaxine 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 that the medication is not a good fit. 

How do your genes relate to desvenlafaxine? 

Genetics can affect your body’s response to medication. They contain instructions to create enzymes that break down medications. The CYP2D6 gene is responsible for the breakdown of desvenlafaxine and many other medications. 

Some people with a certain variation of CYP2D6 might not be able to take some other medication alongside desvenlafaxine. At certain doses, desvenlafaxine can affect the way your body breaks down other medications, which means that these other medications can stick around in your body for longer than usual and cause side effects. To avoid this, people with this variation of the CYP2D6 gene are to avoid taking some other medication alongside desvenlafaxine or only take it under close supervision of a doctor. 

One way to predict whether you’ll have a positive outcome while taking desvenlafaxine 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

• It is important for your doctor to keep tabs on your progress when taking desvenlafaxine in case there’s a need to adjust your dose.
• The medication can cause some teenagers and young adults to feel irritable, agitated, or show other unusual behaviors. Some people may also get suicidal thoughts when taking desvenlafaxine. You should notify your doctor if you notice these and be cognizant of this possible side effect. 
• Notify your doctor if you or anyone in your family has a history of bipolar disorder or any other mental conditions before taking desvenlafaxine. 
• Desvenlafaxine should not be taken concurrently with a class of medicines called monoamine oxidase (MAO) inhibitors. Talk with your doctor first if you need to take any other medication alongside desvenlafaxine. 
• Desvenlafaxine may increase the risk of bleeding problems. Inform your doctor before you take aspirin or any other blood thinning agents alongside desvenlafaxine.  
• Notify your doctor immediately if you feel any discomfort in the chest or cough when taking desvenlafaxine as this might be a sign of lung problems. 

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

Some medications, vitamins, and herbs may interfere with how desvenlafaxine works. Make sure to tell your doctor about all other medications you are taking before starting desvenlafaxine 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.