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Venlafaxine (Effexor): Side Effects, Uses, Interaction and Precautions

Venlafaxine Medication and Drugs

GENERIC NAME— Venlafaxine

BRAND NAME(s)— Effexor XR, Effexor

DRUG CLASS— Serotonin-Norepinephrine Reuptake Inhibitor (SNRI)

What Is Venlafaxine?

Venlafaxine is an antidepressant medication used to treat major depressive disorder, panic disorder, generalized anxiety disorder and social phobia. It belongs to a class of drugs called serotonin-norepinephrine reuptake inhibitor (SNRI).

It is believed that Venlafaxine affects brain chemicals that may be unbalanced in the individuals with depression. The drug may also be used for chronic pain. It is taken by mouth.


Ask your doctor or health care provider while taking this medication with a sleeping pill, muscle relaxer, narcotic pain medication, anxiety or depression medications, or seizures.

Tell your doctor about all medicines you’re currently taking and any you start or stop using; especially —

  • Any other antidepressant
  • Cimetidine
  • St. John’s wort
  • Tramadol
  • Tryptophan
  • Blood thinners such as warfarin, jantoven, coumadin
  • Medicine to treat mood disorders such as buspirone, lithium
  • Medications to treat migraine such as sumatriptan, zolmitriptan

Venlafaxine Side Effects:

Call your doctor if you have —

  • Blurred or tunnel vision
  • Eye pain or swelling
  • Bleeding such as nosebleeds or bleeding gums
  • A seizure (convulsions)
  • Blood in the urine or stools
  • Coughing up blood
  • Cough, chest tightness, trouble breathing
  • Low levels of sodium in the body— slurred speech, severe weakness, headache, confusion, vomiting, hallucinations, slow breathing or feeling unsteady
  • Severe nervous system reaction— high fever, sweating, rigid muscles, confusion, tremors, fast or uneven heartbeats, feeling like you might pass out

See your doctor if you have symptoms of serotonin syndrome, such as—

  • Nausea
  • Vomiting
  • Diarrhea
  • Fever
  • Sweating
  • Shivering
  • Agitation
  • Hallucinations
  • Fast heart rate
  • Muscle stiffness
  • Twitching
  • Loss of coordination

Common side effects of Venlafaxine may include —

  • Dry mouth, yawning
  • Nausea, vomiting, diarrhea
  • Vision changes
  • Fast heartbeats
  • Insomnia
  • Strange dreams, tired feeling
  • Increased sweating
  • Changes in appetite or weight
  • Dizziness, headache, anxiety, feeling nervous
  • Decreased sex drive, erectile dysfunction or impotence, or difficulty having an orgasm


Before taking Venlafaxine, tell your doctor or health care provider if you are allergic to it or if you have a history of any other allergy.

Before taking this medicine, tell your doctor about your medical history, especially of —

  • Bleeding or blood clotting disorder
  • High cholesterol
  • Kidney disease
  • Liver disease
  • Seizure disorder
  • Thyroid disease
  • High blood pressure
  • Diabetes
  • Personal or family history of glaucoma
  • Heart problems such as heart failure, stroke
  • Low levels of sodium in your blood

It is not recommended to take Venlafaxine during pregnancy. It may harm an unborn baby. Consult your doctor if you are pregnant or planning to get pregnant.

The medication can pass into the breast milk and may harm a nursing baby. Ask your doctor if you are breast—feeding.

This medicine is not approved for use by anyone younger than 18 years old.

What Happens If I Missed A Dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost the time for next scheduled dose. Do not take extra drug to make up the missed dose.

What Happens If I Take An Overdose?

Seek emergency medical help or call the Poison Help line at 1—800—222—1222.

What Should I Avoid While Taking Venlafaxine?

Avoid drinking alcohol. Consuming alcohol with this medication can cause unwanted side effects.

Avoid taking nonsteroidal anti-inflammatory drug (NSAID) such as ibuprofen (Advil, Motrin), aspirin, naproxen (Aleve), celecoxib (Celebrex), diclofenac, meloxicam, indomethacin, and others.


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