Indications 

Pristiq, known by its generic name desvenlafaxine, is an orally-administered medication prescribed for the treatment of major depressive disorder (MDD). Its therapeutic effects are attributed to its selective serotonin and norepinephrine reuptake inhibition (SNRI) properties, which potentiate certain neurotransmitters in the central nervous system (CNS).  

By restoring the balance of certain natural substances in the brain, Pristiq effectively manages symptoms of depression, enhances mood, and boosts feelings of well-being and energy levels. This drug is available in extended-release tablet forms of 100 mg and 50 mg. 

Uses and Dosage 

Prior to commencing desvenlafaxine, read the Medication Guide and, if obtainable, the Patient Information Leaflet provided by your pharmacist. This should be done each time you acquire a refill. Should you have any inquiries, kindly seek guidance from your doctor or pharmacist. 

Administer this medication orally, with or without food, as directed by your doctor, usually once a day. The prescribed dosage depends on your medical status and response to treatment. 

Avoid crushing, chewing, or dissolving this medication in water. Such actions can cause an instantaneous release of the entire drug, heightening the possibility of side effects. Swallow the tablets whole. 

To reduce the likelihood of side effects, your physician may recommend starting with a low dose and gradually increasing it. Follow your doctor’s instructions diligently, refrain from exceeding your dose or using the drug more frequently or longer than prescribed. Doing so will neither expedite the improvement of your condition nor decrease your risk of side effects. To maximize the benefits of this medication, take it regularly, ideally at the same time daily. 

Continue using this medication even if you feel better. Refrain from discontinuing the medication without consulting your physician. Some conditions may worsen when the drug is abruptly stopped, and you may experience symptoms such as mood swings, blurred vision, headache, tiredness, sleep changes, and brief electric shock-like sensations. To minimize such effects, your doctor may gradually reduce your dosage before halting the medication altogether. If you experience any new or worsening symptoms, report them immediately. 

If you are transitioning from another antidepressant to desvenlafaxine, your physician should gradually decrease your old antidepressant’s dosage to prevent withdrawal reactions. Please consult your doctor or pharmacist for further details. 

It may take a few weeks before the full benefits of this medication are evident. If your condition fails to improve or worsens, inform your doctor without delay. 

Side Effects 

Allergic Reactions

Please seek emergency medical attention immediately if you experience any of the following signs of an allergic reaction to Pristiq: 

• Skin rash or hives 
• Difficulty breathing 
• Swelling of your face, lips, tongue, or throat 

Severe Side Effects

Inform your healthcare provider right away if you have any new or sudden changes in mood or behavior, including: 

• New or worsening depression or anxiety 
• Panic attacks 
• Trouble sleeping 
• Feelings of impulsiveness, irritability, agitation, hostility, aggression, or restlessness 
• Increased activity or talkativeness 
• Thoughts of suicide or hurting oneself 

Contact your healthcare provider immediately if you experience any of the following: 

• Seizure 
• Easy bruising or bleeding, such as nosebleeds or bleeding gums 
• Blood in urine or stools 
• Coughing up blood 
• Blurred vision, eye pain or swelling, or seeing halos around lights 
• Cough, chest discomfort, or trouble breathing 
• Signs of low blood sodium, which may include:
  • Headache
  • Confusion
  • Problems with thinking or memory
  • Weakness
  • Feeling unsteady 

Please seek immediate medical attention if you experience symptoms of serotonin syndrome, such as: 

• Agitation 
• Hallucinations 
• Fever 
• Sweating 
• Shivering 
• Fast heart rate 
• Muscle stiffness 
• Twitching 
• Loss of coordination 
• Nausea, vomiting, or diarrhea 

Common Side Effects  

• Dizziness, drowsiness, or anxiety 
• Increased sweating 
• Nausea, decreased appetite, or constipation 
• Sleep problems, such as insomnia 
• Decreased sex drive, impotence, or difficulty having an orgasm 

Caution 

Prior to initiating this medication, provide your complete medical history to your healthcare provider, particularly any history of psychiatric conditions like bipolar disorder, bleeding disorders, glaucoma, hypertension, kidney or liver disease, heart issues, stroke, and seizures. Certain medical conditions may significantly impact how your body will respond to this antidepressant. Inform your doctor about all prescription medications, non-prescription drugs, and herbal products.  

Be vigilant for signs of an allergic reaction while on this treatment. If you have a known allergy to desvenlafaxine, venlafaxine, or any inactive ingredients in the tablets, do not take this antidepressant. Symptoms of a severe allergic reaction may include difficulty breathing, swelling of the face and neck, itching, skin rashes, and severe dizziness. If you experience any of these symptoms, seek immediate emergency medical attention. 

As patients take this medication for depression, monitor the risk of suicide. Warning signs of suicide may include feelings of hopelessness, discussing death, changes in sleep patterns, giving away important possessions, and withdrawing from social activities. In case of such signs, have the suicide hotline number readily available. 

Clinical trials have suggested that this medication may pose a risk to unborn babies and breastfed children. Therefore, unless extremely necessary, pregnant and breastfeeding mothers should not take Pristiq.