Pristiq (Desvenlafaxine): Uses, Side Effects, Dosage, & More

What Is Pristiq (Desvenlafaxine)?

Pristiq (Desvenlafaxine) is an FDA-approved medication for treating symptoms of major depressive disorder (MDD) in adults. As a serotonin and norepinephrine reuptake inhibitor (SNRI) class of drugs that may raise the brain’s chemical activity. You may experience mild side effects, such as nausea and sweating, associated with the medication. In extreme cases, Pristiq can cause severe side effects such as suicidal thoughts and serotonin syndrome. The antidepressant is not approved for use in pediatric patients and adolescents.¹

How Does Pristiq Work?

As an SNRI, Pristiq works by affecting the levels of two important brain chemicals, serotonin, and norepinephrine. This helps to increase the concentration of the neurotransmitters in the brain, which play an important role in regulating mood. Also, the antidepressant helps to reduce the symptoms of depression and anxiety.

What is Pristiq Used to Treat?

A doctor may prescribe an SNRI like Pristiq in someone’s treatment for depression when other treatments, such as selective serotonin reuptake inhibitors (SSRIs), have been ineffective in managing depressive symptoms or cause intolerable side effects. However, while the medication can be prescribed for depression, it is only approved for adults as it can cause severe side effects in children and adolescents.

Pristiq can also be a non-FDA-approved (off-label) medication for some conditions. An off-label use of a medication is a use that is not FDA-approved. Prescribers can decide to use a medication off-label because, in their professional judgment, they believe it may benefit someone.² For example, Pristiq can be used off-label to treat hot flashes during menopause in women who cannot take estrogen as a treatment.³

Pristiq is commonly used as an FDA-approved medication to treat:⁴

• Major depressive disorder (MDD) in adults

Pristiq can also be used off-label (non-FDA-approved) for treating:^5,6,7

• Anxiety
• Menopausal hot flashes
• Diabetic neuropathy

Who Should Not Take Pristiq?

Pristiq is not approved for use in children and adolescents. The FDA warns of an increased risk of suicidal thoughts and behavior in children, adolescents, and young adults. After carefully evaluating your symptoms, you must consult your prescriber to understand the right medication you or your family member can take.

Certain groups of people can take Pristiq but need extra caution to prevent the severe side effects of the medication. This is because the medication effects are influenced by various factors such as health conditions and age. Such groups include pregnant and breastfeeding women, people with allergies to other antidepressants, and those with pre-existing medical conditions such as diabetes and high blood pressure.

People who should not take Pristiq:

• Children
• Adolescents

People who may need to avoid taking Pristiq include:

• Pregnant and breastfeeding women
• People with pre-existing health conditions
• People with allergies to other antidepressants

Pristiq Dosages

Pristiq dosages can vary from individual to individual based on several factors, including age, weight, medical history, and the severity of the condition being treated. The typical Pristiq dosage ranges from 50 to 100 mg daily. However, their prescriber may recommend a dosage above 100 mg once daily for some patients. A patient’s dosage is adjusted after careful evaluation of their condition.

Pristiq Dosages for FDA-Approved Treatment

When a medication is FDA-approved, the FDA has reviewed the drug’s effectiveness and safety through clinical trials and has determined that its benefits outweigh its risks. Pristiq is an FDA-approved medication for treating symptoms of depression. The recommended Pristiq dosages may vary depending on an individual’s response to the medication and the severity of the condition.

Pristiq Dosages for Non-FDA-Approved (Off-Label) Uses

Pristiq has been used off-label to treat several mental health disorders, such as menopausal symptoms and anxiety disorders. Off-label use refers to using a drug to treat a medical condition that it has not been approved by the FDA to treat. Healthcare providers can prescribe Pristiq for off-label use if they believe the medication can benefit a patient.

When considering Pristiq for off-label use, healthcare providers have to outweigh the benefits against the side effects and risks of the medication. Your prescriber might consider prescribing Pristiq as a non-FDA-approved (off-label) treatment for other mental health disorders based on factors such as pre-existing medical conditions, your medical history, and current medications that may affect the safety and effectiveness of the medication.

Pristiq Forms & Strengths

Pristiq is available in various forms and strengths. The medication comes in 25 mg, 50 mg tablets, and 100 mg tablets. It comes in extended-release tablets of 25 mg, 50 mg, and 100 mg each, containing 38 mg, 76 mg, or 152 mg of desvenlafaxine succinate.⁸ The medication is also marketed under Khedezla, the same medication but in extended-release form.

Prescribers usually consider various factors when choosing the right form and strength of Pristiq for patients. This includes the disorder being treated, the age of the patient, and the severity of the symptoms. For this reason, prescribers can recommend varying dosages. Also, Pristiq dosage can be adjusted based on the patient’s response to the medication and any side effects they experience.

Pristiq is available in the following forms and strengths:

• 25 milligrams (mg) oral tablet
• 59 milligrams (mg) oral tablet
• 100 milligrams (mg) oral tablet

It is always important to take your medications as prescribed. While Pristiq is usually taken orally with or without food, the extended-release tablet should be swallowed with water without crushing, breaking, or chewing. Also, its recommended to take the medication at approximately the same time each day.

How Should I Take Pristiq?

When taking Pristiq, follow the dosage instructions provided by your doctor. Typically, Pristiq is taken once daily at approximately the same time each day, with or without food. Also, the medication tablet should be swallowed without chewing or crushing. Your healthcare provider can recommend different dosages of Pristiq or prescribe a different form, such as Khedezla, depending on your needs and the condition being treated.

What Happens If I Miss a Dose of Pristiq?

In case you miss a dose of Pristiq, take it as soon as you remember it. However, if it is too close to your next dose, skip the missed dose and resume your regular dosing schedule. Do not try to catch up with extra doses. Also, do not abruptly stop taking Pristiq. Instead, consult your doctor about a plan to safely stop taking the medication.

Side Effects of Pristiq

While Pristiq can help manage symptoms of depression in adults, the antidepressant is associated with common side effects such as nausea, dry mouth, constipation, and sweating. The side effects generally occur due to the direct action of the medication. Common Pristiq side effects should not be of concern as they usually wear off with time, a few days to weeks after the initial dose.

However, in extreme cases, Pristiq can lead to severe side effects such as suicidal thoughts, behaviors, serotonin syndrome, and seizures. These severe side effects usually require immediate medical attention as any further delay can be dangerous in such a way that it can cause sudden death. Serious Pristiq side effects can occur due to underlying medical conditions, the severity of the symptoms, or a patient’s age.

Common Side Effects of Pristiq

Common Pristiq side effects that some can experience include nausea, dizziness, insomnia, or fatigue. The side effects occur as a direct action of the medication on the body. Some may need medical care for symptoms that persist or are intolerable, though many are mild and may not seem as prominent a few days or weeks after the initial dose.

Common side effects of Pristiq include:

• Fatigue
• Decreased appetite
• Nausea
• Dry mouth
• Constipation
• Insomnia
• Sexual problems
• Dizziness
• Sweating
• Sleepiness

Severe Side Effects of Pristiq

Sometimes, common Pristiq side effects can become severe, requiring immediate medical attention. The side effects are usually influenced by several factors, including an individual’s age, pre-existing health condition, and the symptoms’ severity. Severe side effects of Pristiq include serotonin syndrome, suicidal thoughts and behaviors, and seizures.

Severe side effects of Pristiq may include:

• Serotonin syndrome: This is a life-threatening condition that may occur when you take Pristiq with certain medicines. Serotonin syndrome is characterized by signs and symptoms such as agitation and confusion.
• Antidepressant withdrawal: Suddenly stopping Pristiq can cause serious side effects. This can lead to discontinuation syndrome, also known as antidepressant withdrawal. Severe symptoms of Pristiq withdrawal include dizziness and seizures.
• Worsened anxiety symptoms: While taking Pristiq for anxiety may help some manage their symptoms, the medication may sometimes be ineffective, worsening the symptoms.
• Increased chance of bleeding or bruising: Taking Pristiq with other medications like aspirin or blood thinners can increase the risk of bleeding or bruising.
• Angle-closure glaucoma: Pristiq can cause an eye problem called angle-closure glaucoma which can lead to changes in vision.
• Sexual problems: Taking SNRIs like Pristiq can cause sexual problems with symptoms like delayed ejaculation in men and decreased sex drive in women.
• Hyponatremia: Taking Pristiq can cause low blood sodium levels, causing a health condition called hyponatremia.

Pristiq Withdrawal

Like any other medication, Pristiq should be taken as prescribed. Abruptly stopping the medication can cause Pristiq withdrawal, leading to withdrawal symptoms such as dizziness, persistent headaches, irritability, and nausea. Pristiq withdrawal, like other antidepressant withdrawals, can be severe and require immediate medical attention to be safe and effective management of the withdrawal process.

Allergic Reactions to Pristiq

It is highly recommended that you do not take Pristiq if you are allergic to desvenlafaxine succinate, venlafaxine hydrochloride, or any other ingredients in Pristiq. Also, if you are allergic to other antidepressants, you might not be able to take Pristiq. First, consult your health provider, as allergic reactions to Pristiq can cause swelling and breathing trouble.

Allergic reactions to Pristiq may include:

• Breathing trouble
• Swelling
• Rash/hives

The best thing to do if you are experiencing allergic reactions to Pristiq is to seek immediate medical attention. Your prescriber may consider putting you on a different medication after carefully evaluating your condition and determining the cause of the allergy. It is important to follow your prescriber’s instructions to prevent future reactions.

Pristiq Warnings & Precautions

Pristiq is only approved for treating symptoms of depression in adults. The medication is not approved for use in children, adolescents, and adults under age 24 as it can cause severe side effects. Also, the drug is discouraged for use in pregnant and breastfeeding women, people with underlying health conditions, and those with allergic reactions.

Precautions for taking Pristiq include:

• Increased risk of suicidal thoughts: Pristiq can cause suicidal thoughts and behaviors in children and adolescents. This calls for immediate medical attention.
• Symptoms of mania or bipolar disorder: People with symptoms of bipolar disorder or mania are discouraged from taking Pristiq as the medication can cause manic episodes.
• Seizures: Patients with a history of seizure disorder are discouraged from taking the drug as it can cause seizure episodes.
• Bleeding problems: If you have bleeding problems, you should not take Pristiq with advice from your healthcare provider, as the drug increases the risk of bleeding.
• Breastfeeding and pregnant women: Pregnant and lactating women are discouraged from taking Pristiq as the medication can cause severe health effects to an infant and also cause premature labor and miscarriage.
• Alcohol: Taking Pristiq and alcohol together is not encouraged as the drug can cause worsening symptoms of depression, such as dizziness and headaches.

Interactions With Pristiq

As with any other medication, Pristiq can interact with other medications, substances, and herbs, potentially leading to harmful side effects. Its, therefore, important to consult your healthcare provider about all medications, supplements, or herbs you are taking before starting Pristiq to avoid any severe interactions. One possible severe interaction is with monoamine oxidase (MAOI), a medication used to treat depression. Taking Pristiq with MAOIs can result in a life-threatening condition called serotonin syndrome.

6 substances you should avoid while taking Pristiq include:

• St John’s wort: St. John’s wort is a natural herbal supplement that may help alleviate symptoms of mild to moderate depression for some people. Taking Pristiq with St John’s Wort can increase serotonin levels in the body, increasing the risk of serotonin syndrome.
• Other antidepressants: Taking Pristiq with other antidepressants can make you feel very ill and be life-threatening.
• Alcohol: Taking alcohol can increase the nervous system side effects of Pristiq, such as drowsiness and difficulty concentrating.
• Monoamine oxidase (MAOIs): Taking MAOIs within 14 days of stopping your medication increases the risk of serotonin syndrome.
• Migraine medications: Pristiq and migraine medicines can cause dangerous and even life-threatening side effects.
• Nonsteroidal anti-inflammatory drugs (NSAIDs): Taking NSAIDs while on Pristiq can increase the risk of bleeding and easy bruising.

Can You Overdose on Pristiq?

Yes, you can overdose on Pristiq, which can be potentially life-threatening. Pristiq overdose can occur if you take high amounts of Pristiq dosage than the recommended or prescribed by your prescriber. The signs and symptoms of a Pristiq overdose can include dizziness, drowsiness, agitation, confusion, and persistent headaches. If you suspect you have overdosed on Pristiq, call 9-1-1 for an immediate medical emergency.

What Should You Do If You Take Too Much Pristiq?

If you suspect you have taken too much Pristiq, you should seek immediate medical attention. You can call the 9-1-1 emergency hotline for immediate assistance. Come prepared with important information such as your basic medical history, when you took Pristiq, and how much you took.

Questions to Ask Your Healthcare Provide About Pristiq

Suppose you might want to consider using Pristiq medication. It is important to ask your healthcare provider about the medication’s benefits and risks. You can ask your doctor questions like what the side effects of the medication are or how long the medication’s side effects last. Finding the right therapist can benefit depression treatment since therapy and medication can work together to help relieve symptoms.

Questions to ask your care team about Pristiq include:

• Can I use Pristiq along with therapy to treat depression?
• How soon might I notice the side effects of taking Pristiq?
• Am I at risk of more severe symptoms if I am already taking other anxiety/depression medications?
• What is the best dosage for fewer side effects?
• Are there drugs I am taking that could have harmful interactions?
• When should I reach out to you if I am experiencing side effects?
• Is there anything I should tell my therapist about this new medication?
• How often should I come for medical checks ups?
• What should I do if I have a history of allergic reactions?

How to Get a Pristiq Prescription

Suppose you have depression; visiting the nearest hospital for assistance is important. After evaluating your depression symptoms, your healthcare provider will determine the suitable medication to manage your condition. Your healthcare provider can consider Pristiq as a treatment for your depression. Also, you can work with an online psychiatry service if you have fixed schedules.

In My Experience

In my experience, talking to your doctor about your condition is critical before taking any medication. Your doctor will carefully evaluate your condition and determine the right medication. Also, it would be best to ask your healthcare provider questions about your medication and condition. You can ask your doctor questions like how long Pristiq side effects last or the side effects associated with the medication. Another important thing to note is that you should take your medication as prescribed.

For Further Reading

• SNRIs vs. SSRIs: How They Work & Key Differences
• How to Get Antidepressants: Everything You Need to Know
• Finding the Right Therapist
• Online psychiatry service
• Depression treatment