Medically reviewed by Jessica Swirble, PharmD
Last updated on 7/3/2024

Drug Information | Side Effects | Use & Dosage | Request a Prescription

The use of venlafaxine ER can lead to various side effects in some individuals.

Common mild side effects of venlafaxine ER use include:

• Heartburn
  
• Drowsiness
  
• Dizziness
  
• Nightmares
  
• Diarrhea/constipation
  
• Nausea
  
• Headache
  
• Insomnia
  
• Weight loss
  
• Decreased appetite
  
• Fatigue and weakness
  
• Sweating
  
• Hot flashes
  
• Dry mouth
  
• Frequent urination
  
• Tremor
  
• Sexual dysfunction in males and females
  
  

More severe side effects of venlafaxine ER use can include:

• Signs of an allergic reaction (like rash, hives, swelling, difficulty breathing or swallowing)
  
• Chest pain
  
• Seizures
  
• Fast or pounding heartbeats
  
• Increased blood pressure
  
• Blurred vision
  
• Unusual bleeding or bruising
  
• Muscle stiffness
  
• Fever
  
• Sweating
  
• Faintness
  
• Yellowing of skin and eyes
  
• Bloating
  
• Severe changes in mood
  
  

If you experience any severe or concerning side effects while taking venlafaxine ER, contact your healthcare provider right away.

Inform your healthcare provider about any existing medical conditions, allergies, or other medications you are taking before starting treatment with venlafaxine ER. This includes prescription drugs, over-the-counter medications, and dietary supplements, as they may interact with venlafaxine ER.

Tell your provider if you are taking these medications or supplements:

• Amphetamines
  
• Anticoagulants (blood thinners)
  
• NSAIDs (Nonsteroidal Anti-Inflammatory Drugs)
  
• Anxiolytics
  
• Histamine H2-Receptor Antagonists
  
• Antipsychotics
  
• Diuretics (water pills)
  
• Opioids
  
• Antiretrovirals
  
• Antifungals
  
• Mood Stabilizers
  
• Beta Blockers
  
• Antidepressants
  
• Migraine Medications
  
• Weight Loss Medications
  
• Sedatives and Hypnotics
  
• Anticonvulsants
  
• Analgesics
  
  

You should also mention medical conditions such as:

• High blood pressure
  
• Heart attack or heart failure
  
• High cholesterol
  
• Seizures
  
• Glaucoma
  
• Heart disease
  
• Kidney or liver disease
  
• Thyroid disease
  
• Electrolyte abnormalities
  
  

If you are pregnant, planning to become pregnant, or breastfeeding, discuss the potential risks and benefits of using venlafaxine ER with your healthcare provider.

Take venlafaxine ER exactly as prescribed by your healthcare provider. Do not exceed the recommended dose or duration of treatment.

Your provider may direct you to avoid alcohol while taking venlafaxine ER, as it can increase the risk of side effects.

Venlafaxine ER can increase blood pressure. Your provider may recommend that your blood pressure is regularly checked while taking venlafaxine ER.

Complete the full course of treatment, even if you feel better, to ensure the medication's effectiveness in managing your condition.

In case of a venlafaxine ER overdose, seek medical attention immediately. Symptoms of overdose may include severe dizziness, drowsiness, confusion, or rapid heartbeat. If you suspect an overdose, contact the poison control helpline at 1-800-222-1222 or call emergency services.