Venlafaxine

Medically Reviewed by Dr. Harshi Dhingra, M.D.

Last Reviewed: Mar 10, 2023

Side Effects


Venlafaxine ER (EFFEXOR XR) Side Effects

Possible side effects of venlafaxine ER are listed below. Call your doctor for medical advice about side effects if they are severe or if they do not go away in a few days.

  • Drowsiness
  • Dizziness
  • Headache
  • Weakness
  • Unusual dreams or nightmares
  • Heartburn
  • Nausea
  • Vomiting
  • Constipation
  • Stomach pain
  • Gas
  • Change in taste
  • Dry mouth
  • Loss of appetite
  • Weight loss
  • Pain, numbness, tingling, burning in any part of the body
  • Sweating
  • Yawning
  • Difficulty urinating
  • Urinary frequency
  • Enlarged pupils
  • Fever, chills, sore throat, and other signs of infection
  • Sexual problems in males and females

Some of the adverse effects of venlafaxine ER are more serious. Call your doctor right away or seek emergency medical attention if you experience the following symptoms:

  • Skin rash, itching, hives (allergic reactions)
  • Trouble breathing
  • Fast heartbeat
  • Chest pain
  • Seizures
  • Unusual bleeding or bruising, purple spots on the skin
  • Fever, chills, nausea, vomiting, fast heartbeat, confusion, muscle twitching, muscle stiffness
  • Eye pain, blurred vision
  • Bleeding events
  • Hallucinations
  • Problems with coordination
  • Loss of consciousness or coma

The above list may not include all the potential side effects of venlafaxine ER. Contact your healthcare provider if your side effects are unusual or severe or they do not get better over time. You can also report unusual side effects to the Food and Drug Administration at 1-800-FDA-1088.

Venlafaxine ER Overdose: In case of an overdose of venlafaxine ER, call your doctor immediately. You can also call the national poison control center at 1-800-222-1222. Overdose symptoms may include dizziness, drowsiness, nausea, vomiting, muscle pain, enlarged pupils, tingling, numbness, burning, feeling hot or cold, seizures, irregular heartbeat, and loss of consciousness.

Source: FDA