Pristiq Vs Effexor: Differences, Similarities, & Which to Take

Key Differences Between Pristiq & Effexor

The main difference between Pristiq (desvenlafaxine) and Effexor (venlafaxine) is that Pristiq is the active form of Effexor. Effexor contains the active ingredient venlafaxine, while Pristiq contains the active ingredient, desvenlafaxine.² Also, Pristiq’s only FDA-approved use is to treat depression, while Effexor treats depression, general and social anxiety, and panic disorders.³ Both medications are antidepressants known as serotonin and norepinephrine reuptake inhibitors (SNRIs) but they are not considered interchangeable, meaning if you want to switch from one to the other, you will need to discuss the change with your prescriber in order to safely change your medication.

Conditions Treated

Pristiq is Food and Drug Administration (FDA)-approved for major depressive disorder in adults. Effexor is FDA-approved for major depression disorder, generalized anxiety disorder (GAD), social anxiety, and panic disorders in adults. Pristiq is sometimes used off-label, non-FDA-approved) to treat  GAD, social anxiety, panic disorder, post-traumatic stress disorder (PTSD), and migraines. Effexor is sometimes used off-label for attention deficit hyperactivity disorder (ADHD), obsessive disorder (OCD), premenstrual dysphoric disorder (PMDD), hot flashes, and diabetic neuropathy. A prescriber may choose to use a medication off-label based on their professional judgment.

Standard Dosages & Forms

Both Pristiq and Effexor come as extended-release tablets and capsules. Extended release means the medication is released into your body slowly over an amount of time. Neither Pristiq nor Effexor is available in an immediate-release form. The recommended dose for Pristiq is 50 mg once daily with or without food. Although higher doses are available, no additional benefit has been shown for doses greater than 50 mg. It is recommended to take Pristiq in the morning since it can cause insomnia. Also, taking Pristiq with food may help prevent nausea, but it can be taken with or without food.

Effexor’s starting dose is 37.5 mg to 75 mg once daily for most indications except for social anxiety disorder, which is 75 mg once daily. For all indications, the recommended dose is 75 mg once daily. Medications are sometimes started at a lower dose and increased slowly to give your body time to get used to the medication. Since Effexor has the same mechanism of action as Pristiq with similar side effects, it is also recommended to take it in the morning. Effexor should be taken with food. The tablets and capsules should be taken whole and not divided, crushed, chewed, or dissolved. The maximum dosage of Effexor is 225 mg once daily for all indications except for social anxiety disorder which has a maximum dosage of 75 mg once daily.

Side Effects

Pristiq and Effexor are similar in side effects since they are both SNRIs and closely related to one another. However, they differ in their occurrences. The differences occur because Pristiq is the active form of Effexor, so Pristiq is less likely to cause side effects. Also, each drug is unique in that they each have some individual side effects.

Pristiq is less likely than Effexor to cause nausea, insomnia, somnolence, and fatigue, but all of these side effects are still possible. However, it can cause chills, jitteriness, pupil dilation, vertigo, ear ringing, altered taste perception, or hot flashes. Effexor differs in that its side effects are more likely to occur. Also, it can cause diarrhea, anorgasmia, palpitations, and burning or prickling sensations.

The table below summarizes the key differences between Pristiq and Effexor:

Key Components	Pristiq	Effexor
What is the active ingredient and generic name?	desvenlafaxine	venlafaxine
What forms does it come in?	Extended-release tablets and capsules	Extended-release tablets and capsules
What are the typical dosages?	25 mg, 50 mg, and 100 mg	37 mg, 75 mg, 150 mg,

How Are Pristiq & Effexor Similar?

Pristiq and Effexor are SNRIs used as treatments for depression. They enhance your mood, increase cognitive function, and can help change your eating and sleep habits. They have similar uses, side effects, drug interactions, and warnings. Both medications also have similar pricing structures. They are closely related to active ingredients with Pristiq being the active form of Effexor.

Your primary care provider or nurse practitioner can provide you with an SNRI as a depression medication. However, you should typically see a psychiatrist for these medications to determine which is best for you. Typically, your doctor will try all selective serotonin reuptake inhibitors (SSRIs) before trying an SNRI, as each SSRI may have different side effects.

Similarities between Pristiq and Effexor include:

• SNRIs
• Have multiple potential uses both FDA-approved and off-label
• Have similar side effects
• Have similar drug interactions
• Have similar warnings
• Have similar prices

What Is Pristiq?

Pristiq is an SNRI that works by increasing serotonin and norepinephrine in the brain.² It acts by binding to receptors to prevent the breakdown of serotonin and norepinephrine. Serotonin is a naturally occurring neurotransmitter that promotes happiness, sleep, temperature, memory, and hunger. Norepinephrine promotes arousal, attention, and cognitive function.

Pristiq Uses

Pristiq is an SNRI that is FDA-approved to treat major depressive disorder in adults.² A drug that is FDA-approved means it has been proven in randomized controlled clinical trials to be safe and effective for a certain use. Pristiq may be used regardless of depressive severity, and should not be used in children because of its Black Box warning for causing an increased risk of suicidal ideation.

Pristiq is FDA-approved as a treatment for the following disorders:

• Major depressive disorder (MDD)

What Is Effexor?

Effexor is an SNRI that increases the amount of serotonin and norepinephrine in nerve cell connections, gradually increasing the amount the brain produces over time.³ It can take 1-2 weeks for SNRIs to begin working, and up to 4-6 weeks for them to take full effect.

Effexor Uses

Effexor is FDA-approved for major depressive disorder in adults.³ A drug that is FDA-approved means it has been proven in randomized controlled clinical trials to be safe and effective for a certain use. Effexor may also be used for depression regardless of depressive severity. Also, Effexor is not approved for children.

Effexor is FDA-approved as a treatment for the following disorders:

• Major depressive disorder (MDD)
• Generalized anxiety disorder (GAD)
• Social anxiety disorder
• Panic disorder (PD)

What Are Pristiq & Effexor Used to Treat?

Pristiq is FDA-approved for major depressive disorder in adults. A drug that is FDA-approved means it has been proven in randomized controlled clinical trials to be safe and effective for a certain use. Effexor is FDA-approved for major depression disorder, GAD, social anxiety, and PD in adults.

Pristiq is sometimes used off-label for GAD, social anxiety, panic disorder, post-traumatic stress disorder (PTSD), migraines, hot flashes, and neuropathic pain. Off-label means a drug has not been approved by the FDA for a certain use, but a physician may choose to use the medication based on their professional judgment. Effexor is sometimes used off-label for PTSD, migraines, hot flashes, neuropathic pain, attention deficit hyperactivity disorder (ADHD), obsessive disorder (OCD), premenstrual dysphoric disorder (PMDD), and narcolepsy.

The table below compares the medical and mental health conditions Pristiq and Effexor are used to treat: ^{3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18}

Condition	Pristiq	Effexor
Depression	FDA-approved	FDA-approved
GAD	Off-label	FDA-approved
Social Anxiety Disorder	Off-label	FDA-approved
Panic Disorder	Off-label	FDA-approved
PTSD	Off-label	Off-label
Migraines	Off-label	Off-label
Hot Flashes	Off-label	Off-label
Neuropathic Pain	Off-label	Off-label
ADHD	No	Off-label
OCD	No	Off-label
PMDD	No	Off-label
Narcolepsy	No	Off-label

Side Effects of Pristiq & Effexor

Side effects that are common for Pristiq and Effexor include nausea, dizziness, insomnia, somnolence, decreased appetite or weight loss, constipation, dry mouth, sweating, and sexual issues.^2,3 The most common side effect to occur is nausea, with insomnia also being very common. Commonly experienced side effects are often mild, though some may require medical attention.

The table below compares the possible side effects of Pristiq and Effexor:

Side Effects	Pristiq	Effexor
Nausea	Yes	Yes
Vomiting	Yes	Yes
Dizziness	Yes	Yes
Insomnia	Yes	Yes
Somnolence	Yes	Yes
Decreased appetite	Yes	Yes
Constipation	Yes	Yes
Diarrhea	No	Yes
Anxiety	Yes	Yes
Dry mouth	Yes	Yes
Sweating	Yes	Yes
Abnormal ejaculation	Yes	Yes
Impotence	Yes	Yes
Anorgasmia in women	Yes	Yes
Anorgasmia in men	Yes	Yes
Decreased libido	Yes	Yes
Fatigue	Yes	Yes
High Blood Pressure	Yes	Yes
Chills	Yes	Yes
Feeling jittery	Yes	No
Palpitation	No	Yes
Blood vessel dilation	No	Yes
Abnormal dreams	Yes	Yes
Burning or prickling sensations	No	Yes
Tremor	Yes	Yes
Yawning	Yes	Yes
Abnormal vision	Yes	Yes
Pupil dilation	Yes	No
Vertigo	Yes	No
Ear ringing	Yes	Yes
Altered taste perception	Yes	No
Hot flashes	Yes	No

Severe Side Effects & Allergic Reactions for Pristiq & Effexor

The likelihood of experiencing serious side effects or allergic reactions is similar for Pristiq and Effexor, and is rare.^2,3 If you do experience serious side effects or an allergic reaction, talk to your doctor or pharmacist immediately. If you experience an anaphylactic reaction, such as difficulty breathing or speaking, go to the nearest emergency room.

Severe side effects that may occur from taking Pristiq include:

• Elevated blood pressure
• Serotonin syndrome
• Seizures
• Abnormal bleeding
• Increased risk of suicide and worsening depression
• Abnormal bleeding
• Angle-closure glaucoma in certain people
• Activation of mania or hypomania in people who have bipolar
• Low sodium (salt) levels
• Interstitial Lung Disease and Eosinophilic Pneumonia
• Discontinuation syndrome

Severe side effects that may occur from taking Effexor include:

• Elevated blood pressure
• Serotonin syndrome
• Seizures
• Abnormal bleeding
• Increased risk of suicide and worsening depression
• Angle-closure glaucoma in certain people
• Activation of mania or hypomania in people with bipolar disorder
• Low sodium (salt) levels
• Discontinuation syndrome

Warnings & Precautions for Pristiq & Effexor

Pristiq and Effexor are SNRI antidepressants that have warnings to consider before taking them. First, antidepressants can interact with alcohol, causing serious effects. Also, they may need to be avoided during pregnancy and breastfeeding, as it is possible that they can have serious side effects on newborns. In addition, quickly stopping your medication can lead to serious side effects.

Risks to consider when taking Pristiq and Effexor include:^2,3

• Interactions with alcohol: There are no specific interactions between Pristiq, Effexor, and alcohol but it is recommended to avoid alcohol while taking antidepressants. This is because both alcohol and antidepressants act on your brain, so it is possible to have side effects.
• Use while pregnant or breastfeeding: Only certain antidepressants during pregnancy or breastfeeding are recommended. It’s not known if Pristiq or Effexor are safe to take during pregnancy or breastfeeding.
• Antidepressant withdrawal: If you suddenly stop or drastically decrease your dose of an antidepressant that you have been taking for several months, you may experience withdrawal. This is also known as antidepressant discontinuation syndrome. This can be a dangerous condition leading to serious side effects including nausea, irritability or agitation, flu-like symptoms (body aches, sweating, lethargy), headache, dizziness, and increased risk of suicide. You should not stop your medication without talking with your prescriber and developing a plan to slowly taper off the medication.
• Serotonin syndrome: When there is too much serotonin in the body, symptoms occur such as shaking, fever, sweating, fast or irregular heartbeat, and loss of muscle function. Serotonin syndrome can be dangerous and even fatal if not treated. Pristiq and Effexor both have a risk for serotonin syndrome.

Potential Drug Interactions With Pristiq & Effexor

Some substances and medications if taken together with SNRIs can risk serotonin syndrome, a rare but serious side effect. Also, SNRIs are broken down by the same enzymes as some substances and medications and can increase other substances’ absorption. There may also be interactions with SNRIs and substances having similar effects on the body, which increases the risk of side effects.

Disclaimer: Taking certain medications, herbs, or supplements alongside Pristiq and Effexor can change how these medications work in your body or increase the risk for serious side effects. This article does not consider all the possible interactions. Please let your doctor, psychiatrists, and pharmacists know about all the products you currently use, such as prescription medication, nonprescription drugs, and herbal supplements. Do not start, stop, or change the dosage of any medicines without your doctor’s approval.

Substances that can have harmful interactions with Pristiq and Effexor include:

• Alcohol
• St John’s Wort
• Foods high in triptans, such as wheat beer, cheese, and wine

Medications and substances that have harmful interactions with Pristiq and Effexor include:^2,3

Complicating Interactions	Pristiq	Effexor
Monoamine Oxidase Inhibitors (MAOIs)	X	X
Blood thinners	X	X
Non-steroidal anti-inflammatory drugs	X	X
Triptans	X	X
Tryptophan	X	X
Buproprion	X	X
Buspirone	X	X
Tricyclic antidepressants	X	X
SSRIs	X	X
Other SNRIs	X	X
Fentanyl	X	X
Tramadol	X	X
Lithium	X	X
Linezolid	X	X
Atomoxetine	X	X
Dextromethorphan	X	X
Metoprolol, nebivolol, propranolol	X	X
Tolterodine	X	X
Phentermine and other weight loss drugs	X	X
Ondansetron	X	X
Opioids	X	X
Muscle relaxants	X	X
Antipsychotics	X	X
Sleep medications	X	X
Seizure medications	X	X
Alcohol	X	X
St. John's Wort	X	X

Pristiq Vs Effexor: Insurance Coverage & Cost Effectiveness

Both Pristiq and Effexor come as generics that have low costs with most insurances. If you have questions about how much your medication will cost, you should talk with your insurance provider or your pharmacy.

Pristiq Vs Effexor: Key Pros & Cons

Overall, there are few differences between Pristiq and Effexor. They are both approved for depression and have a similar cost, side effect profile, drug interactions, and mechanisms of action. They also share many of the same side effects. The main differences lie in their scope of FDA-approved and dosages.

Pros & Cons of Pristiq

The advantages of Pristiq are that it is less likely to cause nausea, insomnia, and somnolence, and fatigue. It is also not known to cause diarrhea, heart palpitations, and burning or prickling sensations. Disadvantages include potential interactions with potassium (a common supplement), and potential side effects including chills, jitteriness, and a higher risk for serious health conditions including interstitial lung disease and eosinophilic pneumonia.

Pros & Cons of Effexor

The advantages of Effexor are that it has many approved and non-approved uses. Some unique uses of Pristiq include ADHD, OCD, PMDD, and narcolepsy. Also, Effexor is not known to cause pupil dilation, vertigo, ear ringing, altered taste perception, or hot flashes. Disadvantages of Effexor include that its side effects are more likely to occur.

Which Is Right for You: Pristiq or Effexor?

The medication best for your needs can depend on many factors, so you may need to consider online psychiatry services if seeing a doctor in person isn’t feasible. They can help you consider the benefits and risks of each medication. They can also help you decide which medication may work best for you, considering your medical history and history of side effects.

How to Get a Prescription for Pristiq or Effexor

Pristiq and Effexor are only available by prescription, so you should ask your doctor how to get antidepressants. Your primary care provider or nurse practitioner may provide you with an SNRI after trying all SSRIs. However, you should typically see a psychiatrist for these medications to best determine your route of action.

Questions to Ask Your Health Team About Pristiq & Effexor

It is important to have open communication with your doctor so they can accurately decide which medication is best for you. Talk with them about your other medications and substance use to reduce the risk of potentially harmful interactions. Go to your appointment prepared with any questions or concerns you have.

Questions to ask your prescriber about Pristiq and Effexor include:

• Is it safe to take Pristiq or Effexor with my other medications?
• Will Pristiq or Effexor be covered by my insurance?
• Which one has the best results as a treatment for depression?
• Does my medical history increase my risk of side effects for either?
• How long can I expect side effects to last?
• Which one is the best for my treatment of anxiety?
• How often should I see you for checkups while taking Pristiq or Effexor?
• What should I do if I am unsure if antidepressants are right for me?

In My Experience

In my experience, patients tolerate SNRIs well. You may have some side effects that cause you to consider trying a new one. However, keep trying. The right medication is different for each person, and finding one that works for you is incredibly worth it. Also, it’s important to talk to your doctor about this topic and follow their guidance because these medications can have some rare but serious side effects.

For Further Reading

• Lexapro Vs. Prozac: Choosing Which Is Right for You
• Prozac Vs. Zoloft: Choosing the Best for You
• The Inner Compass Initiative
• Anxiety and Depression Associate of America
• Pristiq (Desvenlafaxine) Dosage Guide: Forms, Strengths, & How to Take It