Pristiq Extended release tablets

Pristiq Extended release tablets is a brand of medicine containing the active ingredient desvenlafaxine.

Find out more about active ingredients.

Consumer medicine information (CMI) leaflet

Developed by the pharmaceutical company responsible for this medicine in Australia, according to TGA regulations.


Desvenlafaxine Succinate

Consumer Medicine Information

What is in this leaflet

This leaflet answers some common questions about Pristiq.

It does not contain all the available information. It does not take the place of talking to your doctor or pharmacist or asking questions.

All medicines have risks and benefits. Your doctor has weighed the risks of you taking Pristiq against the expected benefits it will have for you.

If you have any questions about Pristiq, ask your doctor or pharmacist.

Keep this leaflet with your Pristiq tablets. You may need to read it again.

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What Pristiq is used for

What it does

Pristiq is used in the treatment and prevention of relapse of depression.

Depression can affect your whole body and may cause emotional and physical symptoms such as feeling low in spirit, being unable to enjoy life, poor appetite or overeating, disturbed sleep, loss of sex drive, lack of energy and feeling guilty over nothing.

Ask your doctor if you have any questions about why Pristiq has been prescribed for you. Your doctor may have prescribed it for another reason.

How it works

Pristiq contains the active ingredient called desvenlafaxine succinate. It belongs to a class of medications called Serotonin-Noradrenaline Reuptake Inhibitors (SNRIs).

Serotonin and noradrenaline are chemical messengers that allow certain nerves in the brain to work. Pristiq tablets increase the level of these two messengers. Experts think this is how it helps to restore your feeling of wellness.

Pristiq is not addictive.

It is available only with a doctor's prescription.

Use in Children

The safety and effectiveness of Pristiq in children or adolescents under 18 years of age have not been established.

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Before you take Pristiq

When you must not take it

Do not take Pristiq if you are taking other medications for depression known as monoamine oxidase inhibitors, even if you have stopped taking them, but have taken them within the last 14 days.

Do not take Pristiq if you are allergic to desvenlafaxine, venlafaxine or to any of the ingredients listed at the end of this leaflet.

Symptoms of an allergic reaction include:

  • Skin rash
  • Itching or hives on the skin
  • Swelling of the face, lips, tongue, throat or other parts of the body
  • Shortness of breath, wheezing, troubled breathing or difficulty swallowing.

Do not take this medicine after the expiry date (EXP) printed on the pack, or if the packaging is torn or shows signs of tampering. If it has expired or is damaged, return it to your pharmacist for disposal.

If you are not sure whether you should start taking this medicine, talk to your doctor.

Before you start to take it

Tell your doctor or pharmacist if you have allergies to any other medicines, foods, preservatives or dyes.

Tell your doctor or pharmacist if you are pregnant or intend to become pregnant. Pristiq is not recommended for use during pregnancy. Your doctor will discuss the risks and benefits of taking Pristiq if you are pregnant. One of these risks is that newborn babies whose mothers have been taking Pristiq may have several problems including breathing difficulties, seizures and lack of oxygen in their blood.

Tell your doctor or pharmacist if you are breast-feeding or plan to breast-feed. Pristiq passes into breast milk and there is a possibility that the breast-fed baby may be affected. For this reason, the use of Pristiq is not recommended in breast-feeding women.

Tell your doctor if you have, or have had, any medical conditions, especially the following:

  • A history of fits (seizures or convulsions)
  • A personal history or family history of bipolar disorder
  • Blood pressure problems
  • Glaucoma (increased pressure in the eye)
  • A tendency to bleed more than normal or you are taking a blood thinning medication
  • Raised cholesterol or lipid levels
  • Problems with your kidneys or liver
  • Problems with your heart
  • Low sodium levels in your blood
  • Any other medical conditions.

Tell your doctor if you plan to have surgery.

If you have not told your doctor about any of the above, tell them before you start to take Pristiq.

Taking other medicines

Tell your doctor or pharmacist if you take any other medicines, including:

  • all prescription medicines
  • all medicines, vitamins, herbal supplements or natural therapies you buy without a prescription from a pharmacy, supermarket, naturopath or health food shop, such as St John's wort or tryptophan supplements.

Do not start to take any other medicine while you are taking Pristiq, unless it is prescribed or approved by your doctor.

Some medicines may interfere with Pristiq or Pristiq may interfere with these medicines. These include:

  • Medications for depression known as monoamine oxidase inhibitors (MAOIs) (such as moclobemide, phenelzine and tranylcypromine). Tell your doctor if you are taking or have stopped taking them within the last 14 days. Ask your doctor or pharmacist if you are unsure if you are taking any of these medicines. It is important that you do not take Pristiq or medicines similar to Pristiq with MAOIs or within 14 days of taking an MAOI as this may result in a serious life-threatening condition. Your doctor or pharmacist can tell you what to do if you are taking any of these medicines.
  • Any other medications for bipolar disorder, depression, anxiety, obsessive-compulsive disorder or pre-menstrual dysphoric disorder, including St John's wort
  • Drugs that affect serotonin levels e.g. tramadol, dextromethorphan, fentanyl, methadone and pentazocine
  • Medicines for weight loss, including sibutramine
  • Triptans (used to treat migraine)
  • Linezolid (used to treat infections)
  • Drugs that affect your tendency to bleed e.g. aspirin, NSAIDS, warfarin.

You may need to take different amounts of your medicine, or you may need to take different medicines. Your doctor will advise you.

Your doctor or pharmacist has more information on medicines to be careful with or to avoid while taking Pristiq.

Switching to Pristiq from other antidepressants

Side effects from discontinuing antidepressant medication may occur if you are switched from other antidepressants, including venlafaxine, to Pristiq. Your doctor may gradually reduce the dose of your initial antidepressant medication to help reduce these side effects.

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How to take Pristiq

Follow all directions given to you by your doctor or pharmacist carefully. They may differ from the information contained in this leaflet.

If you do not understand the instructions on the box, ask your doctor or pharmacist for help.

How to take it

Swallow the tablets whole with a glass of water or other non-alcoholic liquid.

Do not divide, crush, chew or place the tablets in water.

Do not be concerned if you see a tablet 'shell' in your faeces after taking Pristiq. As the tablet travels the length of your gastrointestinal tract, the active ingredient desvenlafaxine is slowly released. The tablet 'shell' remains undissolved and is eliminated in your faeces. Therefore, even though, you may see a tablet 'shell' in your faeces, your dose of desvenlafaxine has been absorbed.

How much to take

The usual dose is 50 mg taken once daily with or without food.

Do not change your dose unless your doctor tells you to. Your doctor will gradually increase your dose if needed.

If you have kidney problems, you may need a lower dose of Pristiq.

When to take it

Take Pristiq at approximately the same time each day. This could be either in the morning or in the evening.

Taking it at the same time each day will have the best effect. It will also help you remember when to take it.

How long to take it

Continue taking your medicine for as long as your doctor tells you. Although you may begin to feel better after two weeks, it may take several weeks before you feel much better. It is important to give Pristiq time to work.

This medicine helps to control your condition, so it is important to keep taking your medicine even if you feel well.

If you forget to take it

If it is less than 12 hours until your next dose, skip the dose you missed and then take your next dose when you are meant to. Otherwise, take it as soon as you remember, and then go back to taking as you would normally.

Do not take a double dose to make up for the dose you missed. This may increase the chance of you getting an unwanted side effect.

If you are not sure what to do, ask your doctor or pharmacist.

If you have trouble remembering when to take your medicine, ask your pharmacist for some hints.

If you take too much (overdose)

Immediately telephone your doctor or the Poisons Information Centre (telephone: 13 11 26) for advice, or go to Accident and Emergency at your nearest hospital if you think that you or anyone else may have taken too much Pristiq.

Do this even if there are no signs of discomfort or poisoning. You may need urgent medical attention.

Keep the telephone number for these places handy whilst taking any medications.

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While you are taking Pristiq

Things you must do

Visit your doctor regularly for a check up so that your progress can be checked. Always discuss any questions you have about Pristiq with your doctor.

Take Pristiq tablets as your doctor has prescribed.

Tell any other doctors, dentists and pharmacists who treat you that you are taking this medicine.

Keep enough Pristiq tablets to last weekends and holidays. This medicine helps to control your condition, but does not cure it. It is important to keep taking your medicine even if you feel well.

Watch carefully for signs that your depression is getting worse, especially in the first few weeks of treatment or if your dose has changed. Sometimes people with depression can experience a worsening of their depressive symptoms. This can happen even when taking an antidepressant.

Tell your doctor there is the potential for a false positive urinary drug screen while on Pristiq.

Tell your doctor immediately if you experience any of the following symptoms, especially if they are severe, you have not had these symptoms before or they happen very suddenly.

  • Anxiety or agitation
  • Panic attacks
  • Difficulty sleeping
  • Irritability
  • Aggressiveness
  • Hostility or impulsiveness
  • Restlessness
  • Overactivity or uninhibited behaviour
  • Other unusual changes in behaviour
  • Thoughts of suicide.

Tell your doctor immediately if you have any thoughts about suicide or doing harm to yourself.

Warning signs of suicide:

If you or someone you know is showing the following warning signs, contact your doctor or a mental health advisor right away or go to the nearest hospital for treatment.

All thoughts or talk about suicide or violence are serious.

  • Thoughts or talk about death or suicide
  • Thoughts or talk about self-harm or doing harm to others
  • Any recent attempts of self-harm
  • An increase in aggressive behaviour, irritability or agitation.

Things to be careful of

Be careful driving or operating dangerous machinery until you know how Pristiq affects you. Pristiq tablets may make you feel drowsy.

Things you must not do

Do not stop taking Pristiq or change the dose without the advice of your doctor, even if you feel better. Your doctor may want to slowly decrease your dose of Pristiq to help avoid side effects. Side effects are known to occur when people stop taking Pristiq, especially when they suddenly stop therapy.

Some of these side effects include:

  • Headache
  • Nausea
  • Dizziness
  • Tiredness
  • Irritability
  • Anxiety
  • Abnormal dreams
  • Diarrhoea
  • Excessive sweating.

Slowly reducing the amount of Pristiq being taken reduces the possibility of these effects occurring.

Some of these symptoms may impair driving, or the operation of dangerous machinery. Avoid these activities if you experience any of these symptoms.

Avoid drinking alcohol while you are taking Pristiq.

Do not give this medicine to anyone else even if they have the same condition as you.

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Side effects

Tell your doctor or pharmacist as soon as possible if you do not feel well while you are taking Pristiq. All medicines can have side effects. Sometimes they are serious; often they are not. You may need medical attention if you get some of the side effects.

It can be difficult to tell whether side effects are the result of taking this medicine, symptoms of your condition, or side effects of other medicines you may be taking. For this reason it is important to tell your doctor of any change in your condition.

Do not be alarmed by the list of side effects. You may not experience any of them.

Ask your doctor or pharmacist to answer any questions you may have.

Tell your doctor if...

Tell your doctor or pharmacist if you notice any of the following and they worry you:

  • Stomach, bowel or urinary tract problems:
    - Nausea or vomiting
    - Loss of appetite
    - Diarrhoea
    - Constipation
    - Difficulty passing urine
  • Changes in your behaviour:
    - Difficulty sleeping, abnormal sleepiness or abnormal dreams
    - Sexual function problems such as decreased sex drive, delayed ejaculation, problems achieving erection or difficulties achieving orgasm
    - Nervousness or anxiety
    - Feeling jittery or irritable
  • Difficulty thinking or working because of:
    - Yawning
    - Disturbances in concentration
    - Fainting or dizziness after standing up
    - Fatigue
    - Rapid heart beat
    - Chills
    - Headache
  • Excessive sweating
  • Hot flushes
  • Rash
  • Weight loss
  • Weight gain
  • Blurred vision
  • Ringing in the ears
  • Altered taste, dry mouth.

Tell your doctor as soon as possible if...

Tell your doctor as soon as possible if you notice any of the following:

  • Muscle spasms, stiffness, weakness or movement disorders
  • Abnormal facial movements such as tongue thrusting, repetitive chewing, jaw swinging, or grimacing
  • A feeling of apathy or not caring about things
  • Feeling detached from yourself
  • Hallucinations
  • Confusion
  • Agitation
  • Unusually overactive
  • Problems with breathing, shortness of breath
  • Bleeding or bruising more easily than normal
  • Numbness or pins and needles
  • Sensitivity to sunlight.

Go to hospital if...

Tell your doctor immediately, or go to Accident and Emergency at your nearest hospital if you notice any of the following:

  • Swelling of the face, lips, tongue, throat or other parts of the body
  • Seizures or fits
  • Symptoms of sudden fever with sweating, rapid heartbeat and muscle stiffness, which may lead to loss of consciousness.

Tell your doctor or pharmacist if you notice anything else that is making you feel unwell. Other side effects not listed above may also occur in some people. Some of these side effects (for example, increase in blood pressure, increase in blood cholesterol, changes to liver function, protein in the urine) can only be found when your doctor does tests from time to time to check your progress.

This is not a complete list of all possible side effects. Others may occur in some people and there may be some side effects not yet known.

Tell your doctor if you notice anything that is making you feel unwell.

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After taking Pristiq


Keep your Pristiq tablets in their blister pack until it is time to take them. The tablets may not last as well if you take them out of the blister pack.

Keep Pristiq tablets in a cool dry place where the temperature stays below 25°C.

Do not store Pristiq tablets or any other medicine in the bathroom or near a sink. Do not leave Pristiq tablets in the car or on windowsills. Heat and dampness can destroy some medicines.

Keep Pristiq tablets and all medication where young children cannot reach it. A locked cupboard, at least one-and-a-half metres above the ground, is a good place to store medicines.


If your doctor tells you to stop taking this medicine or the expiry date has passed, ask your pharmacist what to do with any medicine that is left over.

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Product description

What Pristiq looks like

There are two strengths of Pristiq tablets:

  • The 50 mg tablet is a light pink, square pyramid tablet debossed with "W" (over) "50" on the flat side.
  • The 100 mg tablet is a reddish-orange, square pyramid tablet debossed with "W" (over) "100" on the flat side.

Each blister pack contains 28 tablets.


Pristiq tablets contain 50 mg or 100 mg desvenlafaxine succinate as the active ingredient.

It also contains the following inactive ingredients:

  • Cellulose-microcrystalline
  • Hypromellose
  • Talc, purified
  • Magnesium stearate
  • Polyvinyl alcohol
  • Titanium dioxide
  • Macrogol
  • Red Iron Oxide
  • Yellow Iron Oxide (50 mg tablet only)
  • Sunset yellow FCF CI15985 (100 mg tablet only).

Pristiq does not contain gluten.


Pristiq tablets are supplied by:
Pfizer Australia Pty Ltd
ABN 50 008 422 348
38-42 Wharf Road
West Ryde NSW 2114
Toll Free Number 1800 675 229

Australian Registration Numbers

  • Pristiq 50 mg tablets:
    - AUST R 170674
  • Pristiq 100 mg tablets:
    - AUST R 170696

Date of Preparation

This leaflet was last revised in January 2016.

® Registered Trademark

© Pfizer Australia Pty Ltd 2016

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CMI provided by MIMS Australia, July 2016  

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