Pristiq Medication Information:

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Pristiq medication comes in several different strengths; click on the strength you need to view prices from pharmacies competing to earn your business.

Pristiq 50 mg
Pristiq ER 50 mg
Pristiq ER 100 mg
Pristiq 100 mg

About Pristiq

What Pristiq is used for

PRISTIQ has been prescribed to you by your doctor to treat your depression. Treatment with these types of medications is most safe and effective when you and your doctor have good communication about how you are feeling.

What Pristiq does

PRISTIQ belongs to a class of medicines called serotonin and norepinephrine reuptake inhibitors (SNRIs). It is thought to work by affecting two naturally occurring brain chemicals, serotonin and norepinephrine.

When Pristiq should not be used

Do not use PRISTIQ if you are:

  • allergic (hypersensitive) to desvenlafaxine, venlafaxine or any of the other ingredients in PRISTIQ.

  • taking or have taken, within the last 14 days, another medicine known as monoamine oxidase inhibitor (MAOI). Taking an MAOI together with many prescription medicines including PRISTIQ can cause serious or even life-threatening side effects. Also, you must wait at least 7 days after you stop taking PRISTIQ before you take any MAOI. (See Other medicines and nutritional or herbal supplements:.)

  • taking other drugs that contain venlafaxine or desvenlafaxine.

  • taking any prescription or non-prescription medicines, including nutritional or herbal supplements without checking with your doctor first (see Serotonin syndrome:).

What the medicinal ingredient is

Desvenlafaxine succinate.

What the important nonmedicinal ingredients for Pristiq are

The nonmedicinal ingredients are: film coating (which consists of dextrose, maltodextrin, sodium carboxymethylcellulose, stearic acid, titanium dioxide and iron oxides), hypromellose, magnesium stearate, microcrystalline cellulose and talc.

What dosage forms Pristiq comes in

  • The 50 mg tablet is a light pink, square pyramid tablet debossed with “W” over “50” on the flat side (50 mg of desvenlafaxine as desvenlafaxine succinate).

  • The 100 mg tablet is a reddish-orange, square pyramid tablet debossed with “W” over “100” on the flat side (100 mg of desvenlafaxine as desvenlafaxine succinate).

PRISTIQ 50 mg, and 100 mg are available in:

  • HDPE bottles of 14, 30 and 90 tablets.

  • Unit dose blister packs of 7, 14 and 28 tablets.

Warnings and Precautions

You have been given PRISTIQ to treat depression. You, your family and caregivers should watch closely for signs of unusual behaviours, depressive symptoms, or suicidal thoughts or behaviours, especially at the start of therapy or any change in dose. Such symptoms should be reported to your health professional right away.

Tell your health professional immediately if you have any distressing thoughts or feelings at any time or if you are feeling changes in mood like sadness, apathy or agitation.

Other medicines and nutritional or herbal supplements

  • Please tell your doctor or pharmacist if you are taking or have recently taken any other medicines, including medicines obtained without a prescription.

  • Avoid taking PRISTIQ with other medicines containing venlafaxine or desvenlafaxine.

  • Your health professional will decide if you can take PRISTIQ with other medicines.

Other medical problems

Tell your doctor if you:

  • are taking other medicines, herbal or nutritional supplements (see Other medicines and nutritional or herbal supplements: and Serotonin syndrome:).

  • have eye problems such as certain kinds of glaucoma (increased pressure in the eye).

  • have a history of high blood pressure.

  • have a history of heart problems.

  • have a narrowing or blockage of your gastrointestinal tract (your oesophagus, stomach, or small or large intestine).

  • have a history of fits (seizures).

  • have a history of low sodium levels in your blood.

  • have a tendency to develop bruises (history of bleeding disorders).

  • have a history of high cholesterol.

  • have a history or family history of mania or bipolar disorder.

  • have kidney problems.

If any of these conditions apply to you, please talk with your doctor before taking PRISTIQ.

PRISTIQ should not be used for children and adolescents under 18 years of age.

Interactions with Pristiq

Do not use PRISTIQ if you are taking or have recently taken monoamine oxidase inhibitors.

Monoamine oxidase inhibitors (MAOI)

Do not take PRISTIQ with an MAOI or within 14 days of stopping an MAOI. Taking an MAOI together with many prescription medicines, including PRISTIQ, can cause serious or even life-threatening side effects. Also, you need to wait at least 7 days after you stop taking PRISTIQ before you take an MAOI.

Avoid taking PRISTIQ with medicines containing venlafaxine or with other medicines containing desvenlafaxine.

Serotonin syndrome

A life-threatening condition called serotonin syndrome (serious changes in how your brain, muscles and digestive system work due to high levels of serotonin in the body) can happen when medicines like PRISTIQ are taken, particularly when taken with certain other medications such as:

  • medicines to treat migraine headaches known as triptans

  • medicines used to treat mood disorders, including tricyclics, lithium, selective serotonin reuptake inhibitors (SSRIs); or serotonin norepinephrine reuptake inhibitors (SNRIs)

  • sibutramine

  • tramadol

  • St. John’s Wort

  • MAOIs (including linezolid, an antibiotic)

  • tryptophan supplements

Before you take PRISTIQ and any of these medicines together, talk to your healthcare professional about the possibility of serotonin syndrome.

Signs and symptoms of serotonin syndrome may include a combination of the following: restlessness, hallucinations, loss of coordination, fast heart beat, increased body temperature, fast changes in blood pressure, overactive reflexes, diarrhea, coma, nausea, vomiting.

Get medical care right away if you think serotonin syndrome is happening to you.

CNS drugs

Caution is advised when PRISTIQ is taken in combination with other centrally acting drugs or substances, including alcohol and sedative drugs (benzodiazepines, opiates, antipsychotics, phenobarbital, sedative antihistamines). Inform your doctor if you are taking any of these drugs.

You should avoid alcohol while taking PRISTIQ.

Proper Use of Pristiq

Always take PRISTIQ exactly as your health professional has told you. You should check with your health professional if you have any questions.

PRISTIQ is for oral use.

  • PRISTIQ should be taken at approximately the same time each day with or without food. Tablets must be swallowed whole with fluid and not divided, crushed, chewed, or dissolved as it is time released.

  • PRISTIQ is prepared as a matrix tablet that slowly releases the medicine inside your body. You may notice something in your stool that looks like a tablet, but it is an empty matrix. Seeing the empty matrix is not a cause for concern. There is no need to take an extra tablet. The active medication has already been absorbed by the time you see the matrix.

Do not stop taking PRISTIQ without talking to your doctor.

Usual dose

The usual dose is 50 mg taken once daily. Your doctor may increase your dose if you need it.


In case of an overdose, call your health professional and/or poison control centre or go to emergency at a hospital right away.

Missed dose

If you miss a dose, take it as soon as you remember. However, if it is almost time for your next dose, skip the missed dose and take only a single dose as usual. Do not take a double dose to make up for a forgotten tablet.

What should you do before stopping PRISTIQ?

Do not stop taking or change the dose of PRISTIQ without first discussing this with your health professional. Your health professional may want to slowly decrease your dose of PRISTIQ to help avoid side effects. Some patients, who suddenly stop taking PRISTIQ after more than 1 week of therapy, have felt dizzy, sick (nausea), had a headache or experienced irritability, insomnia, diarrhea, anxiety, abnormal dreams, fatigue, sweating. These symptoms are usually not serious and disappear within a few days, but if you have symptoms that are troublesome you should ask your doctor for advice.


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