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Venlafaxine (Effexor XR®)

Venlafaxine (Effexor XR® and generic forms) belong to a group of medications called “antidepressants.”

What is this medication used for?

Venlafaxine is not approved by Health Canada for use use in children and adolescents.

However, venlafaxine may help treat depression, generalized or social anxiety disorders, depression associated with bipolar disorder, attention-deficit/ hyperactivity disorder (ADHD), and other anxiety disorders.

When potential benefits outweigh risks, venlafaxine may be prescribed “off-label.” Learn more about off- label medication use:

Tell your doctor or pharmacist if you:

  • Have allergies or bad reactions to a medication
  • Take (or plan to take) other prescription or non- prescription medications, including natural medicines. Some medications interact with venlafaxine. Your doctor may adjust medication doses or monitor for side effects
  • Have a history (or family history) of heart, kidney or liver disease, seizures, bipolar disorder or glaucoma
  • Miss a menstrual period, are pregnant, breast-feeding or planning a pregnancy
  • Use alcohol or street drugs. Taking venlafaxine together with certain substances may cause a bad reaction. Learn more at

When will the medication start to work?

You (or your family members) may notice improvements in sleep, appetite and energy within the first 2 weeks. However, it may take 3 to 6 weeks before you begin to feel better. Full beneficial effects may take 4 to 8 weeks or longer.

Venlafaxine takes time to work. Continue taking venlafaxine as prescribed, even if you are feeling better. Talk with your doctor before you increase, decrease or stop taking venlafaxine.

This medication is not addictive. Do not stop taking it before talking to your doctor.

How do I take this medication?

Venlafaxine is usually taken once daily with food, at the same time each day. Usually, you will start with a low dose and slowly increase this dose over several days to weeks, based on how you tolerate it.

Extended-release venlafaxine capsules should be swallowed whole with fluid. Alternatively, you may sprinkle the entire contents of the capsule(s) on a small amount of applesauce and swallow immediately without chewing. Then drink some fluids to make sure the contents are completely swallowed. The capsules and their contents should not be divided, crushed, chewed or placed in water.

Possible common or serious side effects:

Side effects may be more common when starting a medication or after a dose increase. Talk to your doctor, nurse or pharmacist if any side effect concerns you.

  • Nausea
  • Stomach ache or constipation
  • Decreased appetite or dry mouth
  • Dizziness, drowsiness or headache
  • Sweating or tremors
  • Nervousness or feelings of agitation
  • Abnormal dreams
  • In adolescents/adults: changes in sexual performance or interest

Contact your doctor immediately if you experience:

  • Thoughts of hurting yourself, hostility or suicide
  • Changes in mood to an unusual state of excitement, irritability or happiness
  • Muscle twitches or stiffness
  • Uncomfortable sense of inner restlessness or agitation
  • Unexpected rash, seizure, fever or excessive sweating
  • Unusual bruising or bleeding

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

  • While taking venlafaxine, if you feel dizzy, drowsy or slowed down, do not drive a car or operate heavy machinery. Alcohol could make this worse. Try to avoid alcohol while taking venlafaxine.
  • Venlafaxine and medications like it are associated with a rare side effect called “serotonin syndrome,” especially when used in combination with other serotonergic drugs such as amphetamines and most other antidepressants. Symptoms include diarrhea, sweating, increased heart rate, tremors, severe muscle stiffness and increased agitation.
  • Do not to stop taking venlafaxine suddenly. Stopping abruptly is associated with “antidepressant discontinuation syndrome.” This involves flu-like symptoms, trouble sleeping, nausea, irritability, headache and abnormal sensations that feel like electric shocks, burning, tingling or numbness. If stopping or changing medications, your dose should be reduced slowly.

What special instructions should I follow while using this medication?

  • Keep all appointments with your doctor and the lab.
  • Your doctor may want to talk to you within 1-2 weeks of starting venlafaxine, and meet with you over time to make sure it is working well for you and check for side effects.
  • Do not allow anyone else to use your medication.

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

If you forget to take a dose of venlafaxine, take the missed dose as soon as you remember. However, if it is within 4 hours of your next schedule dose, skip the missed dose and continue with your regular schedule. DO NOT double your next dose to try to ‘catch up’.

How do I store this medication?

Keep venlafaxine in the original container, stored at room temperature away from moisture and heat and protected from light. Keep venlafaxine out of reach and sight of children.

How does this medication work?

Venlafaxine is a Serotonin and Norepinephrine Reuptake Inhibitor (SNRI). Like other SNRIs, venlafaxine increases levels of the brain chemicals serotonin and norepinephrine. These brain chemicals do not function properly in people who have depression or anxiety. The exact way that venlafaxine improves symptoms of depression, anxiety disorders and other conditions is not known. Venlafaxine improves symptoms of ADHD by increasing norepinephrine in areas of the brain that control impulsive actions, attention and body movements.

How well does the medication work in children and adolescents?

Venlafaxine has been studied in children and adolescents with depression and anxiety disorders. It has been shown to be better than placebo (an inactive pill), and comparable to other antidepressants for treatment of depression and anxiety disorders in adolescents. In children, there are mixed results regarding the use of venlafaxine. However, evidence does supports the use of venlafaxine in both children and adolescents with treatment-resistant depression. Whenever possible, the addition of talk therapy, such as Interpersonal Therapy (IPT) for depression or Cognitive Behavioural Therapy (CBT), may help to increase the potential for benefit.

How long should I take the medication for?

This depends on the symptoms you have, how frequently they occur and how long you have had them. Most people need to take venlafaxine for at least 6 months. This allows time for symptoms to stabilize and function to improve. 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 venlafaxine well, you may be asked to take venlafaxine on an ongoing basis. Continuing treatment will significantly decrease the chance that you may have another episode of depression.

Do not increase, decrease or stop taking venlafaxine without discussing it with your doctor, even if you are feeling better. If you stop taking venlafaxine suddenly, it is possible that your symptoms may return or you may have a bad reaction.

TIP: Use the Kelty Mental Health Antidepressant Monitoring Form for Children and Adolescents to help measure your progress on this medication.

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