Skip to Content

Effexor Patient Tips

Written by C. Fookes, BPharm on Nov 07, 2016

How it works

  • Effexor is a brand (trade) name for venlafaxine.
  • Experts believe venlafaxine's effects are due to its ability to block the reuptake of serotonin and norepinephrine, and to some extent dopamine, three neurotransmitters in the brain associated with depression.
  • Venlafaxine belongs to a group of medicines called Selective Serotonin and Norepinephrine Reuptake Inhibitors (SSNRIs).


  • Used for the treatment of significant depression (Major Depressive Disorder).


If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:

  • As with other antidepressants, Effexor may increase the risk of suicidal thoughts or behavior in young adults. Not generally recommended for people under the age of 18.
  • May cause insomnia or drowsiness, headache, anxiety, nausea, nervousness, weight loss, cholesterol elevation, sexual dysfunction as well as several other adverse effects.
  • May be associated with a sustained moderate increase in blood pressure (about 10-15mm Hg) in some people; regular monitoring of blood pressure may be required.
  • In susceptible people, pupil dilation may lead to an episode of angle-closure glaucoma.
  • May impair judgment and affect a person's ability to drive or operate machinery.
  • Interaction or overdosage may cause serotonin syndrome (symptoms include mental status changes [eg, agitation, hallucinations, coma, delirium], fast heart rate, dizziness, flushing, muscle tremor or rigidity and stomach symptoms [including nausea, vomiting, and diarrhea]).
  • May increase risk of bleeding, especially if used with other drugs that also increase bleeding risk.
  • May precipitate a manic episode in people with undiagnosed bipolar disorder.
  • May cause lowering of total body sodium (hyponatremia); elderly people or people taking diuretics or already dehydrated may be more at risk.
  • May cause a discontinuation syndrome if abruptly stopped; symptoms include flu-like symptoms, irritability, low mood, dizziness, electric shock sensations, headache, and confusion. Rarely causes seizures.

Notes: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. For a complete list of all side effects, click here.

Bottom Line

  • Effexor helps to relieve symptoms of depression; however, it has been associated with a discontinuation syndrome on withdrawal.


  • Take with food.
  • Be alert for changes in behavior including agitation, depressed mood, and suicide-related events and seek medical advice if changes are apparent.
  • Do not stop suddenly; it is best to taper off Effexor slowly on a doctor's advice.
  • Do not drive or operate machinery until full effects of Effexor are known as may impair judgment and affect a person's ability to drive or operate machinery.
  • Swallow Effexor XR capsules whole; do not break, crush, or chew or attempt to dissolve in water. If you cannot swallow the capsule whole, the capsule may be opened and the contents sprinkled over a spoonful of applesauce and swallowed without chewing.
  • Seek urgent medical advice if symptoms consistent with serotonin syndrome (such as agitation, hallucinations, fast heart rate, dizziness, flushing, nausea, or diarrhea) develop.
  • Alcohol is best avoided when taking Effexor.
  • Seek urgent advice from an eye professional if eye pain, changes in vision, or swelling or redness around the eye develop.

Response and Effectiveness

  • Peak plasma concentrations occur within one to two hours of taking an immediate-release Effexor tablet; however it may take two to four weeks before a reduction in depressive symptoms are noticed, and up to six to eight weeks before full effects are seen.


Effexor (venlafaxine) [Package Insert]. Revised 01/2010. Wyeth Pharmaceuticals Company

  • Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Effexor only for the indication prescribed.

  • Disclaimer: Every effort has been made to ensure that this information is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. This drug information does not endorse drugs, diagnose patients or recommend therapy. It is an informational resource designed as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of this information. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2017 Revision Date: 2016-11-07 00:00:00