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Venlafaxine Patient Tips

Medically reviewed on Aug 20, 2017 by C. Fookes, BPharm.

How it works

  • Venlafaxine may be used in the treatment of depression. Experts aren't exactly sure how venlafaxine works but believe its effects may be 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).

Upsides

  • Used for the treatment of significant depression (Major Depressive Disorder).
  • Generic venlafaxine is available.

Downsides

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:

  • Nausea, headache, sedation, dry mouth, dizziness, insomnia, nervousness, constipation, and sweating are some of the more commonly reported side effects. May also cause weight loss, cholesterol elevation, sexual dysfunction, and several other side 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.
  • As with other antidepressants, venlafaxine may increase the risk of suicidal thoughts or behavior in young adults. Not generally recommended for people under the age of 18.
  • May impair judgment or cause drowsiness and affect a person's ability to drive or operate machinery. Avoid alcohol.
  • In susceptible people, pupil dilation may lead to an episode of angle-closure glaucoma.
  • 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 the 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 a lowering of sodium levels in the body (this is called hyponatremia). Elderly people or people taking diuretics or who are 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, a headache, and confusion.
  • Rarely causes seizures.
  • May interact with some other medications, including other antidepressants and those metabolized through CYP3A4 or CYP2D6 enzymes, although the degree of interaction appears smaller than with some other antidepressants.

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

  • Venlafaxine is an antidepressant that may cause a discontinuation syndrome if abruptly stopped after long-term administration.

Tips

  • 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 drive or operate machinery until full effects of venlafaxine are known as it may impair your judgment and affect your ability to drive or operate machinery.
  • Swallow extended-release 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 venlafaxine.
  • Do not stop taking venlafaxine suddenly. Your doctor will advise you how to taper it when the time comes to discontinue it.
  • 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 tablet; however, it may take two to four weeks before a reduction in depressive symptoms is noticed, and up to six to eight weeks before the full effects are seen.

References

Venlafaxine [Package Insert]. Revised 05/2017. Aidarex Pharmaceuticals LLC https://www.drugs.com/pro/venlafaxine.html

  • Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use venlafaxine 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. Drugs.com 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 Drugs.com. Revision Date: 2017-08-20 21:15:01

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