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Venlafaxine (Effexor®)

Summary: Venlafaxine (Effexor XR®) belongs to a group of medications called antidepressants. Venlafaxine may also be used to treat several other conditions.
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What is venlafaxine used for?

Venlafaxine is used as part of the treatment of various conditions such as:

  • Depression
  • Depression associated with bipolar disorder
  • Generalized anxiety disorder
  • Attention deficit/hyperactivity disorder (AD/HD)
  • Other anxiety disorders like social phobia

Your doctor may be using this medication for another reason. If you are unclear why this medication is being prescribed, please ask your doctor.

How does venlafaxine work?

Venlafaxine is a “Serotonin and Norepinephrine Reuptake Inhibitor” (SNRI). This means it increases the amount of certain chemicals in the brain called serotonin and norepinephrine. It is believed that these brain chemicals are not working well in people who are depressed The exact way that venlafaxine improves the symptoms of depression is still not fully known. The actions of venlafaxine on norepinephrine activate areas of the brain that control impulsive actions, attention and body movements, resulting in improved symptoms of AD/HD.

Venlafaxine in children and adolescents

Like many medications used to treat childhood disorders, venlafaxine has not been officially approved by Health Canada for use in children and adolescents. When the potential benefits (e.g., reducing your symptoms) of using venlafaxine outweigh the potential risks (e.g., the side effects), many doctors may prescribe it.


Venlafaxine has been studied in children and adolescents with anxiety disorders. In some studies of children and adolescents with depression, medications like venlafaxine have been found to help about 5 to 6 out of every 10 people who are treated. However, some studies have found that venlafaxine was not better at lowering the symptoms of depression compared to a placebo (an inactive pill that looks like the medication). In one study of patients with generalized anxiety, nearly 7 out of every 10 people who were given venlafaxine for 8 weeks improved.


In general, many depressed youth who take venlafaxine for 2-3 months will notice an improvement in their depressive symptoms (such as improved mood, better sleep, more energy, and improved concentration). Whenever possible, the addition of behavioural therapy such as Interpersonal Therapy (IPT) for depression or Cognitive Behaviour Therapy (CBT) to this medication may help to increase the potential for benefits.

How should venlafaxine be taken?

Venlafaxine is usually taken once a day with or without food. This medication should be taken at the same time each day as directed by your doctor. Try to connect it with something you do each day (like eating breakfast or brushing your teeth) so that you don’t forget. Try to avoid alcohol while taking venlafaxine.


Swallow extended release venlafaxine capsules whole with fluid. You may sprinkle the entire contents of the capsule(s) on a small amount of applesauce right before you take a dose. However, if you do sprinkle the capsule contents on applesauce, drink some fluid after swallowing to make sure the contents are completely swallowed. The capsules and their contents should not be divided, crushed, chewed, or placed in water.


Usually, your doctor will start with a low dose of venlafaxine. Then, this dose will be slowly increased based on how you respond to it. You and your doctor can then discuss the best dosage to stay on based on how well you tolerate this medication (how well the medication is working and how you are doing with the side effects of the medication) and how well it helps to decrease your symptoms.

When will venlafaxine start working?

Venlafaxine must be taken for 3 to 6 weeks before you begin to feel better. Different symptoms start to improve at different rates. For example, improvements in sleep, appetite and energy may be seen within the first 2 weeks.


Sometimes, others will notice improvements in you before you do. Full beneficial effects may take 4 to 8 weeks (or longer). Since this medication takes time to work, even if you are feeling better, do not increase, decrease or stop taking it without discussing with your doctor first.


If you are not feeling better within 6 to 8 weeks, your doctor may recommend you take a different medication. There is a small chance that your depressive symptoms may worsen or that you may experience increased thoughts of self harm during the first couple of months of taking this medication (see section on side effects). If this happens, tell your doctor IMMEDIATELY.

How long do I have to take venlafaxine?

This depends on the symptoms you have, how frequently they occur and how long you have had them. Most people need to take this medication for at least 6 months. This allows time for your symptoms to stabilize and for you to regain functioning. After this time, you and your doctor can discuss the benefits and risks of continuing treatment.


If you have had several episodes of severe depression and you tolerate this medication well, you may be asked to take this medication for an indefinite amount of time. By continuing to take this medication, you significantly decrease the chance that you may have another episode of depression. Do NOT stop taking this medication (even if you are feeling better) without discussing it with your doctor first. If you stop taking this medication suddenly, it is possible that your symptoms may return or you may have a bad reaction.


Once you have started taking this medication, you and your doctor will need to monitor for both the beneficial and unwanted effects. Your doctor will check your progress and discuss changes in symptoms during the next 3 months

to confirm that this medication is working properly and that possible side effects are avoided. At this time, you can discuss how long you might need to take this medication.

Is venlafaxine addictive?

No, venlafaxine is not addictive. You will not have “cravings” for it like some people do with nicotine or street drugs. If you and your doctor decide it is best for you to stop using venlafaxine, your doctor will explain how to safely lower the dose so you won’t feel any unpleasant “flu-like” effects (chills, nausea, vomiting, dizziness, tingling in hands and feet, muscle aches, fever and electrical sensations) as your body adjusts to being without it.

What are the side effects of venlafaxine and what should I do if I get them?

As with most medications, side effects may occur when taking venlafaxine. Most side effects are mild and temporary. Side effects may occur before any of the beneficial effects. It is possible for some individuals to experience side effects that they feel are serious or long lasting. If you feel this has happened, speak with your doctor right away.


On the next section are some of the common side effects and potentially serious side effects of taking this medication. In brackets are suggested ways to lessen these effects.


Common side effects


Side effects may be more common when starting a medication or after a dose increase. If any of these side effects is too troublesome for you, please discuss them with your doctor, nurse or pharmacist.

  • Constipation (increase exercise, fluids, vegetables, fruits and fiber intake)
  • Decreased appetite (try eating smaller, more frequent meals)
  • Drowsiness (try taking the dose at bedtime; this usually lessens over time)
  • Difficulty sleeping (try taking the medication earlier in the day)
  • Dizziness (try getting up slowly from a sitting or lying down position)
  • Dry mouth (try chewing sugarless gum, sour candies, ice chips, or popsicles)
  • Energized/agitated feelings (avoid caffeine from energy drinks, colas and coffee)
  • Excessive sweating (strong antiperspirants can help; talk with your doctor or pharmacist)
  • Headache (try using a pain reliever like acetaminophen (plain Tylenol®))
  • Stomach aches or nausea (try taking the venlafaxine dose with food)
  • Unusually vivid dreams
  • In Adolescents/Adults: Changes in sexual performance or interest (discuss with your doctor)

Uncommon side effects (e.g., those that occur in less than 5% of patients)


Contact your doctor IMMEDIATELY if you have any of these side effects:

  • Change in mood to an unusual state of excitement, irritability or happiness
  • Muscle twitches or stiffness
  • Seizures (also called fits or convulsions)
  • Skin rash, itchy skin or hives
  • Thoughts of self harm, hostility or suicide
  • Uncomfortable sense of inner restlessness or agitation
  • Unusual bruising or bleeding

What precautions should my doctor and I be aware of when taking venlafaxine?

Tell your doctor or pharmacist if you:

  • begin taking any other new medication (prescription or non-prescription), since several other medications
  • can interact with venlafaxine
  • feel drowsy, dizzy or slowed down. Venlafaxine can make some individuals experience these temporary side effects. Venlafaxine may increase the effects of alcohol, resulting in more sedation or dizziness.
  • If you feel this way, it is important to avoid operating heavy machinery or driving a car.
  • have a history of diabetes, heart disease, thyroid disease, kidney or liver disease or seizures
  • have any allergies or have experienced a reaction to a medication
  • have any changes in mood or thoughts of self harm
  • if you develop any new medical problem while you are taking venlafaxine
  • miss a period, become pregnant or are trying to become pregnant or are breast-feeding

What special instructions should I follow while using venlafaxine?

  • Keep all appointments with your doctor and the laboratory.
  • Do not allow anyone else to use your medication.
  • It is a good idea to have a visit or telephone call with your doctor within 1-2 weeks after you start taking venlafaxine, and then periodically after that to see how well the medication is working, how well you are tolerating the medication, and to discuss any problems you may have.

What should I do if I forget to take a dose of venlafaxine?


If you miss a dose of this medication, take it as soon as possible. However, if it is almost time for your next dose (e.g., within 4 hours), do not take the missed dose or double your next dose. Instead, continue with your regular dosing schedule.


What storage conditions are needed for venlafaxine?

  • Keep this medication in the original container, stored at room temperature away from moisture and heat (e.g., not in the bathroom or kitchen).
  • Keep this medication out of reach and sight of children.

Share this information

You may wish to share this information with your family members to help them to understand your treatment options. Since every person's needs are different, it is important that you follow the advice provided to you by your own doctor, nurse and/or pharmacist and speak to them if you have any questions about this medication.

About this document

Special thanks to the Kelty Centre for Mental Health for permission to adapt this document. The original document was developed by health professionals of BC Mental Health and Addiction Services, and reviewed by the staff of the Kelty Mental Health Centre. French translation provided courtesy of the Ontario Centre of Excellence for Child and Youth Mental Health.

Creative Commons license

You are free to copy and distribute this material unchanged and in its entirety as long as 1) this material is not used in any way that suggests we endorse you or your use of the material, 2) this material is not used for commercial purposes (non-commercial), 3) this material is not altered in any way (no derivative works). View full license at For any other uses, please contact the original rights holder, the Kelty Mental Health Centre.


Information in this pamphlet is offered ‘as is' and is meant only to provide general information that supplements, but does not replace the information from your health provider. Always contact a qualified health professional for further information in your specific situation or circumstance.

Date Posted: Jun 16, 2013
Date of Last Revision: Oct 9, 2016

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