Desvenlafaxine

Antidepressant Drug

Drug class: Serotonin-Norepinephrine Reuptake Inhibitor

Desvenlafaxine (PRISTIQ)（中文：去甲文拉法辛）

Common Strengths of Desvenlafaxine

Desvenlafaxine are available in the following strengths:

• 25 mg, 50 mg, 100 mg

Drug Trade Names of Desvenlafaxine

Pristiq

Drug Usage

Desvenlafaxine is primarily used to treat:

• Major depressive disorder (MDD) in adults

Mechanism of Action

Desvenlafaxine is a selective serotonin and norepinephrine reuptake inhibitor (SNRI). It works by inhibiting the reuptake of serotonin and norepinephrine, increasing their levels in the brain.

Route of Administration

Oral (extended-release tablets)

Dosages

The recommended dose is 50 mg once daily

Renal dose based on eGFR:

• eGFR ≥50 mL/min: No dosage adjustment is needed
• eGFR 30 - 50 mL/min: Maximum 50 mg/day
• eGFR <30 mL/min: Maximum 25 mg/day or 50 mg every

Side Effects

Frequency	Adverse reactions
Common	Nausea: Stick to simple meals and avoid rich or spicy foods
	Dry Mouth: Chew sugar-free gum or sweets
	Excessive Sweating: Wear loose clothing and use a fan if needed
	Dizziness: Get up slowly from sitting or lying positions
	Constipation: Increase fiber intake and drink plenty of water
	Insomnia: Take in the morning
	Decreased Appetite
	Fatigue or Sleepiness
	Anxiety
	Sexual Dysfunction: includes decreased libido and difficulty achieving orgasm
Serious	Serious side effects are less common but require immediate medical attention
	Suicidal Thoughts or Actions: especially in the first few months of treatment or when the dose is changed. Symptoms include new or worsening depression, anxiety, or unusual changes in mood or behavior.
	Serotonin Syndrome: This potentially life-threatening condition can occur when there is too much serotonin in the body. Symptoms include agitation, hallucinations, rapid heart rate, fever, nausea, vomiting, diarrhea, and muscle twitching
	Severe Allergic Reactions: These include symptoms like difficulty breathing, swelling of the face, lips, tongue, or throat, and severe rash or hives
	Abnormal Bleeding: Can manifest as unusual bruising or bleeding
	Low Sodium Levels: Particularly in older adults, symptoms include headache, confusion, weakness, and difficulty concentrating
	Mania: Symptoms include excessively high energy, severe trouble sleeping, racing thoughts, reckless behavior, and unusually grand ideas
	Eye Problems- Such as blurred vision, eye pain, or swelling, which may indicate glaucoma
	Seizures
	High blood pressure

Pharmacokinetics

• Metabolism: Primarily through conjugation, minor oxidative metabolism
• Elimination: 45% excreted unchanged in urine. Half-life of about 11 hours
• Onset of action: 1 to 4 weeks for full antidepressant effect

Drug Precautions

Pregnancy

Use with caution; potential risks to the fetus.

Breastfeeding

Use with caution; desvenlafaxine is excreted in breast milk

Children and Elderly

• Not approved for use in children
• Elderly may be more sensitive to side effects; lower doses may be needed

Monitoring Requirements

• Blood pressure
• Signs of serotonin syndrome

Drug Interactions

Interaction Type	Examples	Notes
Major	Other serotonergic drugs include other SNRIs, SSRIs, triptans, tricyclic antidepressants, opioids, lithium, buspirone, amphetamines, and St. John’s Wort.	Risk of serotonin syndrome
Moderate	Antiplatelets, Anticoagulants, NSAID, CYP2D6 substrates: dextromethorphan, metoprolol, nebivolol, tolterodine	Increased bleeding risk

FAQ

How Should I Take the Tablet?

Do not chew or crush the tablet. Take the tablet whole with or without food, at approximately the same time each day.

What Should I Avoid While Taking?

Avoid alcohol and operating heavy machinery until you know how desvenlafaxine affects you.

What Happens if I Miss a Dose?

Take the missed dose as soon as you remember unless it is almost time for your next dose. Do not double doses.