Pristiq (Desvenlafaxine Succinate)
Complete patient guide for uses, dosage, side effects, and safety information
Prescription RequiredQuick Facts
What Is Pristiq Used For?
Pristiq contains desvenlafaxine succinate and belongs to a class of medications called Serotonin-Noradrenaline Reuptake Inhibitors (SNRIs). It helps restore your feeling of wellness by increasing levels of important chemical messengers in your brain.
Primary Uses
Pristiq is used for 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.
How It Works
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.
How to Take Pristiq
Take Pristiq exactly as prescribed by your doctor. The medication should be taken at approximately the same time each day for best results.
Dosage Instructions
The usual dose is 50 mg taken once daily with or without food. Swallow tablets whole with a glass of water or other non-alcoholic liquid. Do not divide, crush, chew or place the tablets in water. If you have kidney problems, you may need a lower dose. Your doctor will gradually increase your dose if needed. 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.
What If You Miss a Dose?
If you miss your dose and if it is less than 12 hours until your next dose, skip the dose you missed and 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 as this may increase the chance of getting an unwanted side effect.
Important: Never take a double dose to make up for a missed dose – this may increase your risk of side effects
Available Tablet Strengths
Side Effects
Like all medications, this medicine can cause side effects. Most are mild and temporary, but some require medical attention.
Common Side Effects
These side effects occur relatively frequently and usually don’t require emergency care:
- Nausea or vomiting
- Loss of appetite
- Diarrhoea
- Constipation
- Difficulty passing urine
- 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
- Yawning
- Disturbances in concentration
- Fainting or dizziness after standing up
- Fatigue
- Rapid heartbeat
- Chills
- Headache
- Excessive sweating
- Hot flushes
- Rash
- Weight loss or weight gain
- Blurred vision
- Ringing in the ears
- Altered taste, dry mouth
Seek immediate medical attention if you experience:
- Muscle spasms, stiffness, weakness or movement disorders
- Abnormal facial movements such as tongue thrusting, repetitive chewing, jaw swinging, or grimacing
- 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
- Palpitations, shortness of breath, intense chest pain, or irregular heartbeats
- Severe upper abdominal pain
- Swollen and tender abdomen
- Fever
- Rise or decrease in blood pressure
- 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
- Signs of neuroleptic malignant syndrome or serotonin syndrome
Important Warnings
There are important safety considerations and medical conditions that need to be discussed with your doctor before starting Pristiq.
Who Should Not Take Pristiq
Do not use Pristiq if you are allergic to desvenlafaxine, venlafaxine, or any of the ingredients. 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.
Medical Conditions to Discuss
Check with your doctor if you have: other medications that you are taking, 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, or any other medical conditions.
Pregnancy and Breastfeeding
Pristiq is not recommended for use during pregnancy or breastfeeding. If you take Pristiq or similar anti-depressants mid to late in your pregnancy, you may develop pre-eclampsia (persistent high blood pressure). Newborn babies whose mothers have been taking Pristiq may have breathing difficulties, rapid breathing, seizures, lack of oxygen in their blood, physical and/or behavioural problems, vomiting and diarrhoea. If you take Pristiq in the last month of pregnancy, you may experience heavy bleeding during and/or after delivery. Pristiq passes into breast milk and there is a possibility that the breast-fed baby may be affected.
Suicide Risk: Watch carefully for signs that your depression is getting worse, especially in the first few weeks of treatment or if your dose has changed. Tell your doctor immediately if you have any thoughts about suicide or doing harm to yourself.
Drug Interactions
Some medicines may interfere with Pristiq and affect how it works. Tell your doctor about all medicines you are taking.
- Monoamine oxidase inhibitors (such as moclobemide, phenelzine and tranylcypromine)
- 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 (tramadol, dextromethorphan, fentanyl, methadone and pentazocine)
- Medicines used to treat ADHD (dexamphetamine and lisdexamphetamine)
- Medicines for weight loss, including sibutramine
- Triptans (used to treat migraine)
- Linezolid (used to treat infections)
- Drugs that affect bleeding tendency (Aspirin, NSAIDs, Warfarin)
- Opioids (used to manage pain)
Alcohol & Driving
Pristiq can affect your ability to drive and may interact with alcohol, so important precautions need to be taken.
Alcohol
Avoid drinking alcohol while you are taking Pristiq. Tell your doctor if you drink alcohol.
Driving and Operating Machinery
Be careful before you drive or use any machines or tools until you know how Pristiq affects you. Pristiq may cause dizziness in some people and may make you feel drowsy.
Storage
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. Store in a cool (below 25°C) dry place away from moisture, heat or sunlight. Do not store in the bathroom, near a sink, in the car or on window sills. 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.
Overdose Information
If you think that you have used too much Pristiq, you must seek urgent medical attention. You should immediately phone the Poisons Information Centre (by calling 13 11 26), contact your doctor, or go to the Emergency Department at your nearest hospital. You should do this even if there are no signs of discomfort or poisoning.
Frequently Asked Questions
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.
Yes, the usual dose of 50 mg can be taken once daily with or without food.
Do not stop using this medicine without the advice of your doctor. Your doctor may want to slowly decrease your dose to help avoid side effects. Side effects known to occur when people suddenly stop include headache, nausea, dizziness, tiredness, irritability, anxiety, abnormal dreams, diarrhoea, excessive sweating, visual impairment, and high blood pressure.
No, you should avoid drinking alcohol while you are taking Pristiq. Tell your doctor if you drink alcohol.
If you miss your dose and it is less than 12 hours until your next dose, skip the missed dose and take your next dose when you are meant to. Otherwise, take it as soon as you remember. Do not take a double dose to make up for the missed dose.
No, you must swallow Pristiq tablets whole with a glass of water or other non-alcoholic liquid. Do not divide, crush, chew or place the tablets in water.
Yes, do not be concerned if you see a tablet ‘shell’ in your faeces after taking Pristiq. As the tablet travels through your gastrointestinal tract, the active ingredient is slowly released. The tablet ‘shell’ remains undissolved and is eliminated in your faeces, but your dose has been absorbed.
Important Disclaimer
This information is intended for general educational purposes only and should not be considered medical advice. Always consult your healthcare provider or pharmacist before starting, stopping, or changing any medication.
If you think you may have a medical emergency, call your doctor or emergency services immediately.