Pristiq is a brand-name prescription drug that's used to treat major depressive disorder (MDD) in adults. This condition is a serious mental health condition. It's often called clinical depression, or simply depression.

Pristiq belongs to a class of antidepressants called serotonin-norepinephrine reuptake inhibitors (SNRIs). A class of drugs is a group of medications that work in a similar way. SNRIs increase the level of two chemicals (serotonin and norepinephrine) in your brain.

Pristiq comes as extended-release tablets that are taken once a day. It's available in three strengths: 25 mg, 50 mg, and 100 mg.

Effectiveness

Pristiq has been found effective at treating depression in several clinical studies. The studies used a scale to measure how severe people's depression symptoms were before and after treatment. The scale used is called the Hamilton Rating Scale for Depression (HAM-D). This scale has a minimum score of zero points and a maximum score of 52 points. Higher scores indicate more severe depression symptoms.

In four clinical studies, Pristiq was effective in improving people's depression scores compared to a placebo (treatment with no active drug).

Prior to treatment, people's average depression scores ranged from 23.0 and 25.3 for all four studies. After 8 weeks of treatment, people taking Pristiq (from 50 mg to 400 mg per day) had their depression score lowered by up to 3.3 points.

Two longer-term studies that lasted up to 26 weeks were also done. These studies showed that people taking Pristiq were also less likely to have their depression relapse (come back after improving) compared to those taking placebo.

Pristiq contains the active drug ingredient desvenlafaxine succinate. Generic forms of Pristiq are available. These forms come in the same strengths that Pristiq does.

Generic drugs are usually less expensive than their brand-name form.

Pristiq can cause mild or serious side effects. The following lists contain some of the key side effects that may occur while taking Pristiq. These lists do not include all possible side effects.

For more information on the possible side effects of Pristiq, talk with your doctor or pharmacist. They can give you tips on how to deal with any side effects that may be bothersome.

More common side effects

The more common side effects of Pristiq can include:

  • nausea
  • dry mouth
  • fatigue (lack of energy)
  • dizziness
  • sweating
  • constipation
  • reduced appetite
  • sleepiness (avoid driving until you know how Pristiq affects you)
  • insomnia (trouble sleeping)
  • anxiety
  • sexual problems in men, such as reduced sex drive or trouble getting an erection

Most of these side effects may go away within a few days or a couple of weeks. If they're more severe or don't go away, talk with your doctor or pharmacist.

Serious side effects

Serious side effects from Pristiq aren't common, but they can occur. Call your doctor right away if you have serious side effects. Call 911 if your symptoms feel life-threatening or if you think you're having a medical emergency.

Serious side effects and their symptoms can include the following:

  • Suicidal thoughts and behaviors in children and young adults.* Symptoms can include:
    • worsening depression
    • thoughts about dying or harming yourself
    • attempting suicide
    • new or worsening anxiety or panic attacks
    • feeling very agitated, restless, or unable to be still
    • new or worsening insomnia (trouble sleeping)
    • being irritable, angry, or aggressive
    • extreme levels of excitement and activity, or talking very fast, which may all be considered symptoms of mania
    • acting on impulses without thinking about the consequences
  • Serotonin syndrome (a dangerous condition caused by a buildup of serotonin in your body). Symptoms can include:
    • fast heartbeat
    • dizziness
    • sweating
    • flushing
    • tremor or twitching
    • stiff muscles
    • loss of coordination
    • nausea or vomiting
    • diarrhea
    • agitation
    • hallucinations (seeing or hearing things that aren't real)
    • seizures
    • coma
  • New or worsened high blood pressure. Symptoms can include:
    • headache
    • chest pain
  • Bleeding more easily than usual. Symptoms can include:
    • nosebleeds
    • bruising easily
    • vomiting up blood, which may look red or pink in color
    • bloody stools
    • black-colored stools, which may look like tar
  • Closed-angle glaucoma (sudden buildup of pressure inside your eye). Symptoms can include:
    • seeing haloes around lights
    • blurred vision
    • eye pain or redness
    • sudden severe headache
    • nausea
  • Low sodium level in your blood, which is more likely in adults ages 65 years and older. Symptoms can include:
    • headache
    • trouble concentrating
    • problems with your memory
    • confusion
    • feeling weak and unsteady, which could lead to falls
    • hallucinations
    • fainting
    • seizures
  • Lung problems, such as pneumonia or scarring in your lungs. Symptoms can include:
    • trouble breathing
    • cough
    • chest discomfort
  • Seizures. Symptoms can include:
    • uncontrolled muscle spasms
    • loss of consciousness
    • drooling
    • sudden eye movements
    • loss of bowel or bladder control
  • Severe allergic reactions. Symptoms are discussed in more detail below.

* Pristiq has a boxed warning from the FDA regarding the risk of suicidal thoughts and behaviors. A boxed warning is the strongest warning the FDA requires. It alerts doctors and patients about drug effects that may be dangerous.

Side effect details

You may wonder how often certain side effects occur with this drug, or whether certain side effects pertain to it. Here's some detail on several of the side effects this drug may or may not cause.

Allergic reaction

As with most drugs, some people can have an allergic reaction after taking Pristiq. It's not known how often this occurs. Symptoms of a mild allergic reaction can include:

  • skin rash
  • itchiness
  • flushing (warmth and redness in your skin)

A more severe allergic reaction is rare but possible. Symptoms of a severe allergic reaction can include:

  • swelling under your skin, typically in your eyelids, lips, hands, or feet
  • swelling of your tongue, mouth, or throat
  • trouble breathing

Call your doctor right away if you have a severe allergic reaction to Pristiq. Call 911 if your symptoms feel life-threatening or if you think you're having a medical emergency.

Weight loss or weight gain

You may have weight changes while you're taking Pristiq. But it's not known for sure if the drug causes those weight changes.

Depression, which Pristiq is used to treat, often affects your appetite. If you have depression, your body weight may increase or decrease. When treating depression, it's difficult to know if weight changes happen because your depression has improved, or if they're a side effect of the treatment you're using.

One review looked at the effect Pristiq had on body weight. The review looked at people who had taken Pristiq in studies for 2 months (short-term studies) and 9 months (long-term studies).

People taking Pristiq in the short-term studies had an average weight loss of 1.8 pounds. Those taking a placebo (treatment with no active drug) over the same length of time had an average weight gain of 0.11 pounds.

People taking Pristiq in a long-term study had an average weight gain of less than 2.2 pounds. The same result was seen in people taking a placebo during the study.

Overall, the review found that less than 1% of people taking Pristiq during clinical studies had a significant change in their weight. Also, the length of time (either short term or long term) that people used Pristiq doesn't significantly affect weight changes.

If you're concerned about weight gain or weight loss while you're taking Pristiq, talk with your doctor. They can recommend tips for diet and exercise habits that can help you maintain a healthy weight during your treatment.

Sexual side effects

You may have sexual side effects while you're taking Pristiq. Sexual problems often occur when taking antidepressants, including Pristiq.

In clinical studies, the following sexual side effects were reported by men using Pristiq daily for 8 weeks:

  • reduced sex drive, which occurred in:
    • 4% of men taking 50 mg of Pristiq
    • 5% of men taking 100 mg of Pristiq
    • 6% of men taking 200 mg of Pristiq
    • 3% of men taking 400 mg of Pristiq
    • 1% of men taking a placebo (treatment with no active drug)
  • problems getting an erection, which occurred in:
    • 3% of men taking 50 mg of Pristiq
    • 6% of men taking 100 mg of Pristiq
    • 8% of men taking 200 mg of Pristiq
    • 11% of men taking 400 mg of Pristiq
    • 1% of men taking a placebo
  • delayed ejaculation, which occurred in:
    • 1% of men taking 50 mg of Pristiq
    • 5% of men taking 100 mg of Pristiq
    • 7% of men taking 200 mg of Pristiq
    • 6% of men taking 400 mg of Pristiq
    • less than 1% of men taking a placebo

Sexual problems were also reported by some women taking Pristiq daily for 8 weeks during clinical studies. Of those taking 50 mg or 100 mg of Pristiq, 1% reported that they couldn't reach orgasm. The same problem was reported in 3% of women taking 400 mg of Pristiq. There were no reports of this side effect in women who were taking 200 mg of Pristiq or a placebo each day.

If you have sexual problems while you're taking Pristiq, don't be afraid to discuss them with your doctor. Sexual side effects are a common problem with many antidepressants. These side effects can improve over time. However, switching your treatment to a different antidepressant can sometimes help. Your doctor will recommend if switching medications is a good option for you.

Insomnia

Insomnia (trouble sleeping) is a symptom of depression. However, problems with sleep were also reported in short-term clinical studies of Pristiq. In those taking the drug daily for 8 weeks, insomnia was reported by:

  • 9% of people taking 50 mg of Pristiq
  • 12% of people taking 100 mg of Pristiq
  • 14% of people taking 200 mg of Pristiq
  • 15% of people taking 400 mg of Pristiq
  • 6% of people taking a placebo (treatment with no active drug)

If you have insomnia during Pristiq treatment, it may help to take your daily dose of the drug in the morning, instead of later in the day. If this doesn't help, talk with your doctor about your problems with sleep.

Also, problems with sleep usually begin to improve in the first few weeks after starting Pristiq, as the antidepressant starts to work in your body. If you continue to have problems sleeping after a few weeks of treatment, talk with your doctor about ways to improve your quality of sleep.

Headache

In short-term clinical studies that lasted 8 weeks, 2% of people taking Pristiq stopped taking the drug due to headaches.

A headache can be a symptom of more serious side effects of Pristiq. These side effects include closed-angle glaucoma, high blood pressure, and low sodium levels.

If you get a sudden severe headache while you're taking Pristiq, you should call your doctor right away. But if you get a more mild, typical type of headache, ask your pharmacist to recommend a medication to help relieve your pain.

Sweating

You may have increased sweating while you're taking Pristiq. This side effect was seen in clinical studies of the drug. Of those taking Pristiq daily, increased sweating was reported by:

  • 10% of people taking 50 mg of Pristiq
  • 11% of people taking 100 mg of Pristiq
  • 18% of people taking 200 mg of Pristiq
  • 21% of people taking 400 mg of Pristiq
  • 4% of people taking placebo (treatment with no active drug)

Night sweats specifically weren't reported in these studies. However, night sweats have been reported in people taking a very similar drug called venlafaxine.

If you have increased sweating while you're taking Pristiq, talk with your doctor. They can recommend ways to help manage this side effect.

Diarrhea

Diarrhea wasn't reported as a side effect of Pristiq in clinical studies. However, diarrhea can be a symptom of serotonin syndrome, which is a side effect that can occur with Pristiq.

Serotonin syndrome occurs when levels of a chemical called serotonin get too high in your body. This condition is more likely to occur if you're taking other drugs that also increase serotonin levels with Pristiq.

Other symptoms of serotonin syndrome include:

  • fast heartbeat
  • dizziness
  • sweating
  • flushing
  • tremor or twitching
  • stiff muscles
  • loss of coordination
  • nausea or vomiting
  • agitation
  • hallucinations (seeing or hearing things that aren't real)
  • seizures
  • coma

If you have diarrhea along with any of these symptoms, call your doctor right away. They can recommend whether you need medical attention.

Constipation

You may have constipation while you're taking Pristiq. This side effect was seen in short-term clinical studies of the drug. Of those taking Pristiq daily for 8 weeks, constipation was reported in:

  • 9% of people taking either 50 mg or 100 mg of Pristiq
  • 10% of people taking 200 mg of Pristiq
  • 14% of people taking 400 mg of Pristiq
  • 4% of people taking a placebo (treatment with no active drug)

If you feel constipated while taking Pristiq, make sure you drink plenty of water and include high-fiber foods in your diet. Doing gentle exercise, such as going for a walk, can also help ease constipation. As an added benefit, exercise is known to improve your mood and help relieve symptoms of depression.

If you have constipation that's not improving with these measures, talk with your doctor. They can recommend ways to help treat this side effect.

Hair loss

You may have hair loss while you're taking Pristiq. This side effect was reported by less than 2% of people taking Pristiq in clinical studies.

If you're concerned about hair loss, talk with your doctor. They may order tests to see why you're having hair loss, and they'll also recommend ways to help you manage this side effect.

Suicidal thoughts and behaviors

Some children and young adults have a higher risk of suicidal thoughts and behaviors while they're taking an antidepressant.

Clinical studies found that this risk is higher in children, adolescents, and young adults (under 25 years of age). This risk is highest during the first few months of treatment and after any changes to dosage. Pristiq is not approved for use in children (people under 18 years of age).

While taking Pristiq, call your doctor right away if you:

  • feel that your depression symptoms are getting worse
  • have thoughts about dying or harming yourself
  • try to harm yourself or attempt suicide
  • have sudden changes in your mood, feelings, thoughts, or behavior, such as:
    • new or worsening anxiety or panic attacks
    • feeling very agitated, restless, or unable to be still
    • new or worsening insomnia (trouble sleeping)
    • being irritable, angry, or aggressive
    • extreme levels of excitement and activity, or talking very fast, which may all be considered symptoms of mania
    • acting on impulses without thinking about the consequences

Suicide prevention

If you think someone is at immediate risk of self-harm or hurting another person:

  • Call 911 or your local emergency number.
  • Stay with the person until help arrives.
  • Remove any guns, knives, medications, or other things that may cause harm.
  • Listen, but don't judge, argue, threaten, or yell.

If you or someone you know is considering suicide, get help from a crisis or suicide prevention hotline. Try the National Suicide Prevention Lifeline at 800-273-8255.

The Pristiq dosage your doctor prescribes may depend on a few factors, including how well your liver and kidneys work.

The following information describes dosages that are commonly used or recommended. However, be sure to take the dosage your doctor prescribes for you. Your doctor will determine the best dosage to suit your needs.

Drug forms and strengths

Pristiq comes as extended-release tablets. It's available in three strengths: 25 mg, 50 mg, and 100 mg.

Dosage for major depressive disorder

The recommended starting dosage of Pristiq is 50 mg taken by mouth once a day.

It's best to take your dose at the same time each day. You should continue taking 50 mg each day for as long as your doctor recommends.

The maximum dose of Pristiq is 400 mg each day. (If you have liver or kidney problems, your maximum dosage may be lower.) However, Pristiq dosages that are higher than 50 mg daily haven't been shown to be more effective. Higher doses of the drug are also more likely to cause side effects.

What if I miss a dose?

If you forget to take a dose of Pristiq at your usual time, take it as soon as you remember. However, if it's almost time for your next dose, just skip the missed dose. Then, take your next dose at your usual time.

Don't take more than one dose of Pristiq to make up for a missed dose. Doing this can increase your risk of certain side effects.

To help make sure that you don't miss a dose, try setting a reminder on your phone. A medication timer may be useful, too.

Will I need to use this drug long term?

Pristiq is meant to be used as a long-term treatment. Clinical guidelines for depression treatment recommend that you keep taking your antidepressant for 4 to 9 months after your depression symptoms improve. Staying on treatment helps reduce your risk of depression coming back.

In some people, depression is more likely to come back after they stop taking antidepressants. People at higher risk of this happening are those who've had several episodes of depression, or those with a family history of psychiatric illness.

If you have these risk factors, it's recommended that you take antidepressants for a longer time before stopping the medications. This helps lower your risk of your depression coming back.

If you and your doctor determine that Pristiq is safe and effective for your depression, you may take the drug long term.

The Food and Drug Administration (FDA) approves prescription drugs such as Pristiq to treat certain conditions. Pristiq may also be used off-label for other conditions. Off-label use is when a drug that's approved to treat one condition is used to treat a different condition.

Pristiq for major depressive disorder

Pristiq is FDA-approved to treat major depressive disorder (MDD) in adults. MDD is another name for clinical depression. It's often just called depression.

MDD is a serious mental health condition. With MDD, you may feel sad and hopeless over a long period of time. You may also feel irritable, anxious, tired, and lacking energy. As well as having these feelings, you may also have physical symptoms, such as trouble sleeping or changes in your appetite. These feelings and physical problems can have a significant impact on your daily life.

Effectiveness for major depressive disorder

Pristiq has been found effective at treating depression in several clinical studies. The studies used a scale to measure how severe people's depression symptoms were before and after treatment. The scale used is called the Hamilton Rating Scale for Depression (HAM-D). This scale has a minimum score of zero points and a maximum score of 52 points. Higher scores indicate more severe depression symptoms.

In four clinical studies, Pristiq was effective in improving people's depression scores compared to a placebo (treatment with no active drug).

Prior to treatment, people's average depression scores ranged from 23.0 and 25.3 for all four studies. After 8 weeks of treatment, people taking Pristiq (from 50 mg to 400 mg per day) had their depression score lowered by up to 3.3 points.

Two longer-term studies that lasted up to 26 weeks were also done. These studies showed that people taking Pristiq were also less likely to have their depression relapse (come back after improving) compared to those taking placebo.

Pristiq for other conditions

In addition to the use listed above, Pristiq may be used off-label. Off-label drug use is when a drug that's approved for one use is used for a different one that's not approved. And you may wonder if Pristiq is used for certain other conditions.

Pristiq for menopausal symptoms (off-label use)

Pristiq isn't approved to treat menopausal symptoms, but sometimes it's used off-label to treat menopausal hot flashes.

Pristiq can reduce how many hot flashes you have and how severe they are. One review of studies looked at people taking desvenlafaxine (the active drug in Pristiq). These people had 55% to 69% fewer hot flashes with treatment than they had prior to treatment.

If you're interested in using Pristiq to treat menopausal hot flashes, talk with your doctor. They can discuss with you all of your treatment options and recommend which options are safest for you.

Pristiq for anxiety and social anxiety disorder (not an appropriate use)

Pristiq isn't approved to treat anxiety or social anxiety disorder.

One review looked at the effect that desvenlafaxine (the active drug in Pristiq) had on anxiety symptoms in people with major depressive disorder. The review found that desvenlafaxine improved anxiety symptoms in people with depression much more than a placebo (treatment with no active drug) improved their symptoms. However, this doesn't mean that Pristiq will be effective for treating anxiety that's not associated with depression.

One small 12-week study looked specifically at using Pristiq to treat social anxiety disorder. This study found that Pristiq improved people's anxiety symptoms more than a placebo (treatment with no active drug) improved their symptoms. However, this study was small and only included 63 people. Larger studies are needed to know if Pristiq would be effective in treating social anxiety disorder.

Many other antidepressants, including venlafaxine (Effexor XR), are used to treat anxiety. Venlafaxine is very similar to desvenlafaxine (the active drug in Pristiq). Venlafaxine is approved to treat generalized anxiety disorder, social anxiety disorder, and panic disorder.

Pristiq shouldn't be used to treat anxiety disorders until more studies have shown that it's effective for these conditions.

If you're interested in taking Pristiq to treat anxiety, talk with your doctor. They can recommend treatment options that are safe and effective to treat your anxiety.

Pristiq for OCD (not an appropriate use)

Pristiq isn't approved to treat obsessive-compulsive disorder (OCD). The drug's effectiveness for treating this condition hasn't been studied.

Some other antidepressants are approved to treat OCD. With this condition, you may have obsessive (repetitive) thoughts that cause anxiety. You may do certain actions to help ease these thoughts and anxieties.

If you're interested in taking Pristiq to treat OCD, talk with your doctor. They can recommend treatment options that are safe and effective to treat your condition.

Pristiq for bipolar disorder (not an appropriate use)

Pristiq isn't approved to treat depression caused by bipolar disorder.

Bipolar disorder (formerly called manic depression) is a mental illness that involves episodes of depression (feeling sad or hopeless) and episodes of mania (having extreme levels of excitement and activity). People with bipolar disorder may have unstable moods over long periods of time.

Antidepressants are sometimes used to treat depression caused by bipolar disorder. However, the antidepressants usually have to be taken in combination with a mood-stabilizing drug. Otherwise, taking antidepressants alone can increase your risk of triggering a manic episode.

Before you're given Pristiq to treat your depression, your doctor will check to make sure that you don't have bipolar disorder. If you do have bipolar disorder, your doctor may recommend other medications for you to take with Pristiq.

Pristiq for pain (under study)

Pristiq isn't approved to treat pain of any kind. However, some other antidepressants are approved to treat certain types of pain. Examples of these types of pain include nerve pain and fibromyalgia. With fibromyalgia, people have long-term, widespread pain in their muscles and bones.

One study looked at people with diabetic neuropathy. This is a painful condition resulting from nerve damage in people with diabetes. The study found that Pristiq (at a dosage of 200 mg or 400 mg each day) was more effective than a placebo (treatment with no active drug) in relieving people's pain.

Two other studies looked at people with fibromyalgia. These studies didn't find that Pristiq was effective for relieving people's fibromyalgia pain.

If you're interested in taking Pristiq to treat pain, talk with your doctor. They can recommend treatment options that are safe and effective to treat your condition.

Stopping Pristiq suddenly can cause withdrawal symptoms. You shouldn't stop taking this drug abruptly.

Examples of withdrawal symptoms that can occur if you suddenly stop taking Pristiq include:

  • nausea
  • sweating
  • dizziness
  • headache
  • feeling irritable or agitated
  • anxiety
  • confusion
  • diarrhea
  • feeling pins and needles or having electric shock sensations
  • tinnitus (ringing or other noise in your ears)
  • insomnia (trouble sleeping)
  • abnormal dreams
  • tremor
  • seizures

If you and your doctor decide that you should stop taking Pristiq, it's best to stop the drug gradually. Doing so will help you avoid withdrawal symptoms. Your doctor will explain how to reduce your dose gradually when you're ready to stop treatment.

You shouldn't drink alcohol while you're taking Pristiq. Drinking alcohol can increase your risk for having side effects from Pristiq. These side effects include:

  • feeling sleepy
  • dizziness
  • having sexual problems

Drinking alcohol can also make your depression symptoms worse. If you drink alcohol, talk with your doctor about whether it's safe for you to continue drinking while you're taking Pristiq.

Other drugs are available that can treat major depressive disorder. Some may be better suited for you than others.

Pristiq belongs to a class of antidepressants called serotonin-norepinephrine reuptake inhibitors (SNRIs). A class of drugs is a group of medications that work in a similar way. Other SNRIs and drugs from other classes of medications are also available to treat depression.

If you're interested in finding an alternative to Pristiq, talk with your doctor. They can tell you about other medications that may work well for you.

Examples of other antidepressant drugs that are used to treat major depressive disorder include:

  • other serotonin-norepinephrine reuptake inhibitors (SNRIs), such as:
  • selective serotonin reuptake inhibitors (SSRIs), such as:
  • tricyclic antidepressants (TCAs), such as:
    • amitriptyline
    • clomipramine (Anafranil)
    • desipramine (Norpramin)
    • doxepin (Sinequan)
    • imipramine (Tofranil)
    • nortriptyline (Pamelor)
    • protriptyline (Vivactil)
    • trimipramine (Surmontil)
  • monoamine oxidase inhibitors (MAOIs), such as:
    • phenelzine (Nardil)
    • isocarboxazid (Marplan)
    • tranylcypromine (Parnate)
    • selegiline (Emsam)
  • other antidepressants, such as:

You may wonder how Pristiq compares to other medications that are prescribed for similar uses. Here we look at how Pristiq and Effexor XR are alike and different.

About

Pristiq contains desvenlafaxine, while Effexor XR contains venlafaxine. Both drugs belong to a class of antidepressants called serotonin-norepinephrine reuptake inhibitors (SNRIs). A class of medications is a group of drugs that work in a similar way in your body.

Desvenlafaxine and venlafaxine are closely related. Venlafaxine (the drug in Effexor XR) is metabolized (broken down) by your liver. One of the substances that's made during this process is desvenlafaxine (the drug in Pristiq). Desvenlafaxine is known as an active metabolite of venlafaxine. When you take venlafaxine, most of the antidepressant effect in your body is actually produced by desvenlafaxine.

Uses

Both Pristiq and Effexor XR are approved to treat major depressive disorder (MDD) in adults. MDD is often called depression.

Effexor XR is also approved to treat:

Drug forms and administration

Pristiq comes as extended-release tablets. It's available in three strengths: 25 mg, 50 mg, and 100 mg. Pristiq is taken by mouth once daily. It should be swallowed whole, and it can be taken with or without food.

Effexor XR comes as extended-release capsules. It's also available in three strengths: 37.5 mg, 75 mg, and 150 mg. Effexor XR is taken by mouth once each day. Effexor XR capsules can be swallowed whole. Or the capsules can be opened and sprinkled onto a spoonful of applesauce. The applesauce should then be swallowed without chewing, followed by drinking a glass of water to make sure the drug is completely swallowed. With either option, Effexor XR should be taken with food.

Side effects and risks

Pristiq and Effexor XR are closely related. Therefore, both medications can cause very similar side effects. Below are examples of these side effects.

More common side effects

This list contains examples of the more common side effects that can occur with either Pristiq or Effexor XR (when they're taken individually):

  • nausea
  • vomiting
  • sleepiness
  • insomnia (trouble sleeping)
  • unusual dreams
  • sexual problems
  • reduced appetite
  • constipation
  • dizziness
  • sweating
  • anxiety
  • diarrhea
  • dry mouth
  • yawning
  • tremor
  • fast heart rate

Serious side effects

This list contains examples of serious side effects that can occur with either Pristiq or Effexor XR (when they're taken individually):

  • suicidal thoughts and behaviors in children and young adults*
  • serotonin syndrome (a dangerous condition caused by buildup of serotonin in your body)
  • new or worsened high blood pressure
  • bleeding more easily than usual
  • closed-angle glaucoma
  • low sodium level in your blood
  • lung problems
  • seizures
  • severe allergic reaction

* Pristiq and Effexor XR both have a boxed warning from the FDA regarding the risk of suicidal thoughts and behaviors. A boxed warning is the strongest warning the FDA requires. It alerts doctors and patients about drug effects that may be dangerous.

Effectiveness

Pristiq and Effexor XR have different FDA-approved uses, but they're both used to treat major depressive disorder (MDD).

One review of clinical studies found that, in general, these two drugs had similar effectiveness for treating depression. Both drugs are recommended as MDD treatment options in guidelines from the American Psychiatric Association.

Costs

Pristiq and Effexor XR are both brand-name drugs. There are generic forms of both drugs available. Brand-name medications usually cost more than generics.

According to estimates on GoodRx.com, Effexor XR generally costs more than Pristiq. The actual price you'll pay for either drug depends on your insurance plan, your location, and the pharmacy you use.

You may wonder how Pristiq compares to other medications that are prescribed for similar uses. Here we look at how Pristiq and Cymbalta are alike and different.

About

Pristiq contains desvenlafaxine, while Cymbalta contains duloxetine. Both drugs belong to a class of antidepressants called serotonin-norepinephrine reuptake inhibitors (SNRIs). A class of medications is a group of drugs that work in a similar way in your body.

Uses

Both Pristiq and Cymbalta are approved to treat major depressive disorder (MDD) in adults. MDD is often called depression.

Cymbalta is also approved to treat:

Drug forms and administration

Pristiq comes as extended-release tablets. It's available in three strengths: 25 mg, 50 mg, and 100 mg. Pristiq is taken by mouth each day. It can be taken with or without food.

Cymbalta comes as delayed-release capsules. It's available in three strengths: 20 mg, 30 mg, and 60 mg.

Cymbalta capsules are typically taken once or twice a day. They can be taken with or without food.

Side effects and risks

Pristiq and Cymbalta are both from the same class of drugs. Therefore, both medications can cause very similar side effects. Below are examples of these side effects.

More common side effects

This list contains examples of more common side effects that can occur with either Pristiq or Cymbalta (when they're taken individually):

Serious side effects

These lists contain examples of serious side effects that can occur with Pristiq, with Cymbalta, or with both drugs (when taken individually).

  • Can occur with Pristiq:
    • lung problems
    • severe allergic reactions
  • Can occur with Cymbalta:
    • liver problems, such as liver failure
    • orthostatic hypotension (a drop in your blood pressure when you stand up that can cause you to feel dizzy or faint)
    • severe skin reactions
    • urinary retention (difficulty urinating or not being able to urinate)
  • Can occur with both Pristiq and Cymbalta:

* Pristiq and Cymbalta both have a boxed warning from the FDA regarding the risk of suicidal thoughts and behaviors. A boxed warning is the strongest warning the FDA requires. It alerts doctors and patients about drug effects that may be dangerous.

Effectiveness

Pristiq and Cymbalta have different FDA-approved uses, but they're both used to treat major depressive disorder (MDD).

These drugs haven't been directly compared in clinical studies. But separate studies have found both Pristiq and Cymbalta to be effective for treating depression. Both drugs are recommended as MDD treatment options in guidelines from the American Psychiatric Association.

Costs

Pristiq and Cymbalta are both brand-name drugs. There generic forms of both drugs available. Brand-name medications usually cost more than generics.

According to estimates on GoodRx.com, Pristiq generally costs more than Cymbalta. The actual price you'll pay for either drug depends on your insurance plan, your location, and the pharmacy you use.

Using more than the recommended dosage of Pristiq can lead to serious side effects.

Overdose symptoms

Symptoms of an overdose can include:

  • fast heartbeat
  • larger-than-normal pupils
  • vomiting
  • being unusually sleepy
  • seizures
  • heart rhythm changes
  • low blood pressure
  • dizziness
  • muscle aches and pains
  • coma

What to do in case of overdose

If you think you've taken too much of this drug, call your doctor. You can also call the American Association of Poison Control Centers at 800-222-1222 or use their online tool. But if your symptoms are severe, call 911 or go to the nearest emergency room right away.

Pristiq can interact with several other medications. It can also interact with certain supplements.

Different interactions can cause different effects. For instance, some interactions can interfere with how well a drug works. Other interactions can increase side effects or make them more severe.

Pristiq and other medications

Below are lists of medications that can interact with Pristiq. These lists do not contain all the drugs that may interact with Pristiq.

Before taking Pristiq, talk with your doctor and pharmacist. Tell them about all prescription, over-the-counter, and other drugs you take. Also tell them about any vitamins, herbs, and supplements you use. Sharing this information can help you avoid potential interactions.

If you have questions about drug interactions that may affect you, ask your doctor or pharmacist.

Pristiq and linezolid or methylene blue

Do not take Pristiq if you're receiving treatment with linezolid (Zyvox) or methylene blue (Provayblue). Taking Pristiq with these drugs increases your risk of a serious side effect called serotonin syndrome. This is a dangerous condition caused by high levels of a brain chemical called serotonin in your body.

Pristiq, linezolid, and methylene blue can all raise your level of serotonin. When these drugs are taken together, your level of serotonin may be raised even higher.

If you need treatment with either linezolid or methylene blue, you'll first need to stop taking Pristiq. Your doctor will monitor you closely for signs of serotonin syndrome. You can start taking Pristiq again 24 hours after your last dose of linezolid or methylene blue.

Pristiq and MAOI antidepressants

Taking Pristiq with a monoamine oxidase inhibitor (MAOI) increases your risk of a serious side effect called serotonin syndrome. This is a dangerous condition caused by having high levels of a brain chemical called serotonin in your body.

MAOIs are a class of antidepressants. A class of drugs is a group of medications that act in a similar way. MAOIs and Pristiq both increase levels of serotonin in your body.

Don't take Pristiq if you've taken an MAOI in the past 14 days. Don't take an MAOI until at least 7 days have passed since you've stopped taking Pristiq.

Examples of MAOI antidepressants that should not be taken with Pristiq include:

  • phenelzine (Nardil)
  • isocarboxazid (Marplan)
  • tranylcypromine (Parnate)
  • selegiline (Emsam)

Pristiq and other antidepressants

Taking Pristiq with certain other antidepressants can increase your risk of serotonin syndrome. This is a dangerous condition caused by high levels of a brain chemical called serotonin in your body. Pristiq and certain other antidepressants all work by raising your levels of serotonin.

Examples of other antidepressants that can increase your risk of serotonin syndrome if taken with Pristiq include the following.

  • selective serotonin reuptake inhibitors (SSRIs), such as:
  • other serotonin-norepinephrine reuptake inhibitors (SNRIs) besides Pristiq, such as:
  • tricyclic antidepressants, such as:
    • amitriptyline
    • desipramine (Norpramin)
    • imipramine (Tofranil)

Taking SSRIs or other SNRIs with Pristiq also raises your risk of bleeding problems.

Talk with your doctor about the medications you're taking with Pristiq. Your doctor can help make sure the drugs you're taking are safe to be used together.

Pristiq and lithium

Taking Pristiq with lithium (Lithobid) can increase your risk of serotonin syndrome. This is a dangerous condition that results when levels of a brain chemical called serotonin get too high in your body. Pristiq and lithium both increase your levels of serotonin.

If you're taking lithium, talk with your doctor before you start taking Pristiq. They may recommend different treatment options for you.

Pristiq and buspirone

Taking Pristiq with buspirone can increase your risk of serotonin syndrome. This is a dangerous condition that results from high levels of a brain chemical called serotonin inside your body. Both Pristiq and buspirone can increase your levels of serotonin.

If you're taking buspirone for anxiety, talk with your doctor before you start taking Pristiq. They may recommend that you take a different drug to treat your anxiety.

Pristiq and certain drugs for migraine

Taking triptan medications with Pristiq could increase your risk of a serious side effect called serotonin syndrome. This is a dangerous condition that occurs when levels of a brain chemical called serotonin get too high in your body. Triptan medications and Pristiq both increase your levels of serotonin.

Triptan medications are used to treat migraine and cluster headaches. Examples of triptan medications that increase your risk for serotonin syndrome if taken with Pristiq include:

  • almotriptan (Axert)
  • eletriptan (Relpax)
  • frovatriptan (Frova)
  • naratriptan (Amerge)
  • rizatriptan (Maxalt)
  • sumatriptan (Imitrex)
  • zolmitriptan (Zomig)

If you're taking a triptan medication, talk with your doctor before you start taking Pristiq. They may recommend that you take a different drug to treat your headaches.

Pristiq and certain pain medications

Taking tramadol (ConZip, Ultram) or fentanyl (Duragesic, Subsys, Actiq, others) with Pristiq increases your risk of serious side effect called serotonin syndrome. This is a dangerous condition that results when levels of a brain chemical called serotonin get too high in your body. Pristiq, fentanyl, and tramadol can all increase your serotonin levels.

Tramadol and fentanyl are used to treat pain. If you're taking tramadol or fentanyl, talk with your doctor before you start taking Pristiq. They may switch you to a different medication to treat your pain.

Pristiq and Adderall or other amphetamines

Taking amphetamine drugs, including Adderall, with Pristiq increases your risk of a serious side effect called serotonin syndrome. This is a dangerous condition that occurs when levels of a brain chemical called serotonin get too high in your body. Both amphetamines and Pristiq can increase your serotonin levels.

Examples of amphetamine drugs that increase your risk of serotonin syndrome if taken with Pristiq include:

  • amphetamine (Evekeo, Adzenys, Dynavel)
  • amphetamine and dextroamphetamine (Adderall, Mydayis)
  • dextroamphetamine (Dexedrine)
  • methamphetamine (Desoxyn)

If you're taking an amphetamine drug, talk with your doctor before you start taking Pristiq. They may recommend that you use a different medication while you're taking Pristiq.

Pristiq and anti-inflammatory drugs

Taking a nonsteroidal anti-inflammatory drug (NSAID) with Pristiq can increase your risk of bleeding problems. Taking these drugs together particularly increases your risk of bleeding in your stomach and intestines.

Examples of NSAIDs that increase your risk of bleeding if taken with Pristiq include:

If you're taking an NSAID, talk with your doctor before you start taking Pristiq. They may recommend different treatment options for you.

If you do happen to take an NSAID with Pristiq, tell your doctor right away if you have unusual bruising or bleeding. You should call your doctor right away if you have any blood in your vomit or stools.

Pristiq and anticoagulant (blood-thinning) drugs

Anticoagulant drugs are taken to treat or prevent blood clots. Taking Pristiq with an anticoagulant drug can increase your risk of bleeding problems.

Examples of anticoagulant drugs that increase your risk of bleeding problems if taken with Pristiq include:

  • apixaban (Eliquis)
  • dabigatran (Pradaxa)
  • edoxaban (Savaysa)
  • rivaroxaban (Xarelto)
  • warfarin (Coumadin)

If you're taking an anticoagulant, talk with your doctor before you start taking Pristiq. You may need extra monitoring for abnormal bleeding while you're taking the drugs together. Tell your doctor right away if you have any unusual bruising or bleeding.

Pristiq and diuretics

If you take a diuretic medication with Pristiq, you may have a higher risk of hyponatremia (low level of sodium in your blood).

Diuretic medications help your body to lose excess fluid. These drugs can sometimes cause your sodium level to drop. Pristiq can also have this effect in your body.

Examples of diuretic medications that increase your risk for hyponatremia include:

  • bendroflumethiazide (Naturetin)
  • furosemide (Lasix)
  • hydrochlorothiazide

If you're taking a diuretic medication, talk with your doctor before you start taking Pristiq. You may need blood tests to monitor your sodium level. Also, be sure to tell your doctor if you have any symptoms of low blood sodium.

Symptoms of hyponatremia may include:

  • headache
  • difficulty concentrating
  • memory problems
  • confusion
  • feeling weak or unsteady on your feet

Pristiq and herbs and supplements

Certain herbs and supplements may interact with Pristiq. You should talk with your doctor or pharmacist about any herbs or supplements you're taking with Pristiq.

Pristiq and St. John's wort

You shouldn't take St. John's wort (also called Hypericum perforatum) with Pristiq. Taking this herb with Pristiq raises your risk of a serious side effect called serotonin syndrome.

Serotonin syndrome is a dangerous condition that can occur if levels of a brain chemical called serotonin get too high in your body. Both St. John's wort and Pristiq can raise your serotonin levels.

Pristiq and tryptophan

You shouldn't take tryptophan supplements with Pristiq. Doing this increases your risk of a serious side effect called serotonin syndrome. This is a dangerous condition that occurs if levels of a brain chemical called serotonin get too high in your body. Both tryptophan and Pristiq can raise your serotonin levels.

Here are answers to some frequently asked questions about Pristiq.

Will I feel 'high' if I take Pristiq?

No, taking Pristiq won't make you instantly feel happy or feel "high." This drug works over time to correct the chemical imbalances in your brain that are causing your depression. Taking Pristiq improves your depression symptoms over a period of time and helps you get back to feeling like your old self.

Is Pristiq a controlled substance?

No, Pristiq isn't a controlled substance. Controlled substances are drugs that are prescribed and dispensed under federal laws. These laws help ensure that certain drugs are safely given to people because these drugs can sometimes be misused.

Pristiq belongs to a class of antidepressants called serotonin-norepinephrine reuptake inhibitors (SNRIs). Antidepressants don't produce effects that make them likely to be misused, so they're not controlled substances.

Can I take Xanax for anxiety if I'm taking Pristiq?

Yes, you can take Xanax (alprazolam) to treat anxiety while you're taking Pristiq if recommended by your doctor. However, if you find that Pristiq makes you feel sleepy, taking Xanax will likely make this worse. You shouldn't drive or operate machines until you know how the combination of drugs affects you.

I've noticed what looks like a pill in my stool. Does this mean I didn't get my full dose of Pristiq?

The shell (outer covering) of Pristiq tablets can pass through your digestive tract without being digested (broken down). This is normal, and you may see the tablet's shell in your stool. Don't worry though, because your full dose of Pristiq will have been absorbed into your body.

Pristiq hasn't been studied in pregnant women. However, there have been studies looking at a very similar antidepressant (called venlafaxine) when taken by pregnant women.

Venlafaxine is metabolized (broken down) by your liver. One of the chemicals made in this process is called desvenlafaxine. This chemical is the active drug in Pristiq. Taking Pristiq during pregnancy could have similar effects in your body as taking venlafaxine does.

Risks of Pristiq use during pregnancy

Clinical studies have shown that women taking venlafaxine during pregnancy may have an increased risk of developing preeclampsia. With this condition, you develop high blood pressure during or shortly after your pregnancy. Women taking venlafaxine near delivery may also have an increased risk of bleeding during delivery or after they have given birth.

Studies have also shown that babies born to mothers who are taking venlafaxine or Pristiq may be at risk for certain complications when they're born. These complications may include problems with:

  • breathing
  • feeding
  • maintaining body temperature
  • regulating blood sugar

However, it's important to know that untreated depression during pregnancy can also lead to serious consequences for both the mother and baby.

If you're pregnant or plan to become pregnant, talk with your doctor about the possible risks and benefits of taking Pristiq during pregnancy.

What you can do

If you get pregnant while you're taking Pristiq, let your doctor know as soon as possible. It's important that you don't suddenly stop taking Pristiq. Doing this can cause withdrawal symptoms. (See the section "Pristiq withdrawal" above.)

If you do take Pristiq during pregnancy, talk with your doctor about participating in the pregnancy exposure registry. This registry follows pregnant mothers taking antidepressants and their babies. The registry can help identify effects that may occur when antidepressants are used during pregnancy. This knowledge can help other pregnant women make informed decisions when they're deciding whether or not to take an antidepressant.

It's not known if Pristiq is safe to take during pregnancy. If you're sexually active, and you or your partner can become pregnant, talk with your doctor about your birth control needs while you're using Pristiq.

Pristiq may pass into breast milk in small amounts. One small study did not find any unwanted effects in breastfed children whose mothers were taking Pristiq. However, larger studies are needed to know for sure whether it's safe to use Pristiq while breastfeeding.

Not much is known about how Pristiq could affect children who are breastfeeding. Talk with your doctor about the best way to feed your child while you're taking Pristiq.

As with all medications, the cost of Pristiq can vary. To find current prices for Pristiq in your area, check out GoodRx.com:

The cost you find on GoodRx.com is what you may pay without insurance. The actual price you'll pay depends on your insurance plan, your location, and the pharmacy you use.

Financial and insurance assistance

If you need financial support to pay for Pristiq, or if you need help understanding your insurance coverage, help is available.

Pfizer Inc., the manufacturer of Pristiq, offers a savings card that may help lower the cost of Pristiq. For more information and to find out if you're eligible for support, call 855-440-6852 or visit the program website.

The manufacture also offers a program called Pfizer RxPathways, which can help you understand your insurance coverage of the drug and give you more information on financial assistance. You can learn more by visiting the program website or calling 844-989-PATH (844-989-7284).

You should take Pristiq according to your doctor or healthcare provider's instructions.

When to take

You should take Pristiq once each day. You can take it at any time of the day, but try to stick to the same time each day.

To help make sure that you don't miss a dose, try setting a reminder on your phone. A medication timer may be useful, too.

Taking Pristiq with food

You can take Pristiq with or without food.

Can Pristiq be crushed, split, or chewed?

No. You should swallow Pristiq tablets whole with something to drink. Don't crush, break, chew, or dissolve the tablets.

Pristiq is an extended-release tablet. It's made to release the medication slowly as the tablet passes through your system. If you damage the tablet by crushing, splitting, dissolving, or chewing it, you'll stop the extended-release design from working properly.

Pristiq is approved to treat major depressive disorder (MDD) in adults. This condition is also called depression.

What depression does

When you have depression, the levels of certain chemicals in your brain have become unbalanced. These chemicals are called neurotransmitters. They include serotonin and norepinephrine.

Neurotransmitters help pass messages between the nerve cells in your brain. Serotonin and norepinephrine are involved in passing messages that help regulate your mood and behavior. With depression, the nerve cells in your brain release less serotonin and norepinephrine than usual.

What Pristiq does

Pristiq belongs to a class of antidepressants called serotonin-norepinephrine reuptake inhibitors (SNRIs). A class of medications is a group of drugs that work in a similar way. SNRIs work by increasing the levels of serotonin and norepinephrine in your brain. Over time, this can improve your symptoms of depression.

Pristiq is not intended to change your personality or make you instantly feel happy. Instead, it's meant to work over a period of time to correct the chemical imbalances that play a role in causing your depression symptoms.

How long does it take to work?

It can take 2 to 4 weeks for Pristiq to begin working and for you to start feeling better. You may notice that problems with your appetite, sleep, and concentration start to improve before your mood begins to change.

It's important to keep taking Pristiq, even if you feel like it's not making much of a difference at first. Treatment may take several months before you feel that your depression symptoms have resolved.

You should visit your healthcare provider regularly during treatment, especially when you've just started Pristiq. Talk with your doctor if you feel like your depression has gotten worse with Pristiq. Let them know right away if you have any disturbing changes in your thoughts, feelings, or behavior after starting the drug.

This drug comes with several precautions.

FDA warning: suicidal thoughts and behaviors

This drug has a boxed warning. This is the most serious warning from the Food and Drug Administration (FDA). A boxed warning alerts doctors and patients about drug effects that may be dangerous.

Antidepressants (including Pristiq) increase the risk of suicidal thoughts and actions in some children and young adults under 25 years of age. This risk is more likely to be increased during the first few months after starting an antidepressant and after any dose changes. Pristiq is not approved for use in children under 18 years of age.

While taking Pristiq, call your doctor right away if you:

  • feel that your depression is getting worse
  • have sudden changes in your mood, feelings, thoughts, or behaviors
  • have thoughts about dying or harming yourself
  • try to harm yourself or attempt suicide

Other precautions

Before taking Pristiq, talk with your doctor about your health history. Pristiq may not be right for you if you have certain medical conditions or other factors affecting your health. These include:

  • An allergy to venlafaxine (Effexor) or desvenlafaxine. You shouldn't take Pristiq if you're allergic to desvenlafaxine (the drug in Pristiq) or venlafaxine (a drug very similar to Pristiq). Talk with your doctor about any medication allergies before you start taking Pristiq.
  • High blood pressure. Taking Pristiq can increase your blood pressure. If you have high blood pressure, you may need to take medication to treat it before you take Pristiq. Your doctor will check your blood pressure regularly while you're taking Pristiq. If your blood pressure increases, you may need treatment for it. If your blood pressure remains high on treatment, your doctor may need to lower your dose of Pristiq. They may also recommend that you take a different antidepressant.
  • Heart disease. Taking Pristiq can raise your blood pressure, which could worsen heart disease you may have. Your doctor will check your blood pressure on a regular basis while you're taking Pristiq. Talk with your doctor about any history of heart or blood pressure problems before starting Pristiq.
  • Stroke or mini-stroke. Taking Pristiq can raise your blood pressure, which could increase your risk of having a stroke if you've had one in the past. Tell your doctor if you have a history of stroke or blood pressure problems. Your doctor will check your blood pressure regularly while you're taking Pristiq.
  • Bipolar disorder (manic depression), mania, or hypomania. If you or someone you're closely related to have ever had these mental health problems, Pristiq may not be safe for you. If antidepressants are used alone in people with bipolar disorder, the drugs can increase your risk of having a manic episode. Pristiq is not approved to treat bipolar depression. Before starting Pristiq, talk with your doctor about any mental health problems you've had in the past.
  • Epilepsy or other conditions that cause seizures. Seizures were reported in some people taking Pristiq in clinical studies. Pristiq hasn't been studied in people with epilepsy or a history of seizures. If you have these conditions, your doctor will recommend whether or not Pristiq is safe for you to take. Tell your doctor if you have a history of seizures, of if you have more seizures than usual after starting Pristiq.
  • Bleeding problems. Pristiq can increase your risk of bleeding. If you have any bleeding problems, your doctor will recommend whether or not Pristiq is safe for you to use. Talk with your doctor about any history of bleeding problems.
  • High levels of fats, such as cholesterol or triglycerides. Pristiq can increase cholesterol or triglyceride levels in some people. If your levels are already high, you may need blood tests during Pristiq treatment to make sure the condition is not getting worse. Talk with your doctor about any history of high cholesterol or triglycerides before you start taking Pristiq.
  • Low sodium levels. Pristiq can lower blood sodium levels in some people. This is more likely in older people (ages 65 years and older) and in people taking diuretic medications. (Diuretics are drugs that help remove excess fluid from your body. They're sometimes called water pills.) If your sodium level is already low, taking Pristiq could lower it even further. If this happens, you may need to stop treatment. Before starting Pristiq, talk with your doctor if you're taking a diuretic of if you've had low sodium levels.
  • Kidney problems. If you have problems with your kidneys, your body may not be able to clear Pristiq as well as it normally could. If you have moderate kidney problems, you shouldn't take more than 50 mg of Pristiq per day. If you have severe kidney problems, you shouldn't take more than 25 mg of Pristiq per day, or 50 mg every other day. Talk with your doctor about any kidney problems you've had before you start taking this drug.
  • Liver problems. If you have problems with your liver, your body may not be able to clear Pristiq as well from as it normally could. If you have moderate to severe liver problems, you shouldn't take more than 100 mg of Pristiq each day. Talk with your doctor about any liver problems you've had before you start taking this drug.
  • Pregnancy. Talk with your doctor about the risks and benefits of taking Pristiq during pregnancy. For more information, please see the section "Pristiq and pregnancy" above.
  • Breastfeeding. Pristiq may pass into human breast milk. For more information, please see the section "Pristiq and breastfeeding" above.

Note: For more information about the potential negative effects of Pristiq, see the "Pristiq side effects" section above.

When you get Pristiq from the pharmacy, the pharmacist will add an expiration date to the label on the bottle. This date is typically one year from the date they dispensed the medication.

The expiration date helps guarantee the effectiveness of the medication during this time. The current stance of the Food and Drug Administration (FDA) is to avoid using expired medications. If you have unused medication that has gone past the expiration date, talk to your pharmacist about whether you might still be able to use it.

Storage

How long a medication remains good can depend on many factors, including how and where you store the medication.

Pristiq tablets should be stored at room temperature in a tightly sealed container away from light. Pristiq shouldn't be stored at a temperature higher than 86°F (30°C). Avoid storing this medication in areas where it could get damp or wet, such as in bathrooms.

Disposal

If you no longer need to take Pristiq and have leftover medication, it's important to dispose of it safely. This helps prevent others, including children and pets, from taking the drug by accident. It also helps keep the drug from harming the environment.

The FDA website provides several useful tips on medication disposal. You can also ask your pharmacist for information on how to dispose of your medication.

The following information is provided for clinicians and other healthcare professionals.

Indications

Pristiq is approved to treat major depressive disorder in adults.

Mechanism of action

Pristiq contains desvenlafaxine, the major active metabolite of the antidepressant venlafaxine. Desvenlafaxine is a serotonin-norepinephrine reuptake inhibitor (SNRI). The exact mechanism for how the drug works is not known.

Pharmacokinetics and metabolism

The bioavailability of desvenlafaxine is approximately 80% after oral intake of Pristiq . Steady state is achieved after 4 to 5 days if dosed once daily. Desvenlafaxine is 30% bound to plasma proteins.

Desvenlafaxine is mainly cleared from the body by the kidneys as unchanged drug. A small amount of the drug is metabolized by hepatic conjugation and subsequently excreted in the urine.

Maximum concentration (Cmax) and area under the curve (AUC) of desvenlafaxine are increased in people with moderate to severe hepatic and renal impairment.

Drugs that affect CYP450 enzymes do not significantly affect the metabolism of desvenlafaxine. Desvenlafaxine does not inhibit or induce CYP450 enzymes. This drug is not a substrate or inhibitor of P-glycoprotein.

Contraindications

Pristiq is contraindicated in people:

  • with an allergy to venlafaxine, desvenlafaxine, or any of the excipients of Pristiq
  • who have taken an MAOI for psychiatric indications in the last 14 days
  • being treated with linezolid or methylene blue

Storage

Pristiq tablets should be stored at room temperature. They should not be stored at a temperature higher than 86°F (30°C).

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up-to-date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or other healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.