Uses

What is venlafaxine used for?

Venlafaxine is commonly used for the following conditions.

  • Depression 
  • Anxiety 
  • Social anxiety disorder (SAD), a condition where you have fear and anxiety about social situations 
  • Panic disorder, a condition where you have frequent and unexpected panic attacks

Venlafaxine may also be used for other conditions as determined by your healthcare provider.

How does venlafaxine work (mechanism of action)?

Venlafaxine is an antidepressant that belongs to a group of medicines called serotonin-norepinephrine reuptake inhibitors (SNRIs). It works by increasing the amount of natural chemicals called serotonin and norepinephrine in the brain.

How is venlafaxine supplied (dosage forms)?

Venlafaxine is available as Effexor XR and generic venlafaxine in the following dosage forms that are taken by mouth.

  • 37.5 mg, 75 mg, 150 mg extended-release oral capsules
  • 37.5 mg, 75 mg, 112.5 mg, 150 mg, 225 mg extended-release oral tablets
  • 25 mg, 37.5 mg, 50 mg, 75 mg, 100 mg oral tablets 

How should I store venlafaxine?

Venlafaxine should be stored at room temperature, between 68 F to 77 F (20 C to 25 C). It can be exposed to temperatures between 59 F to 86 F (15 C to 30 C), for shorter periods of time, such as when transporting it. Store in a cool, dry place. 

Side Effects

What are the most common side effects of venlafaxine?

The most common side effects of venlafaxine are listed below. Tell your healthcare provider if you have any of these side effects that bother you.

  • Unusual dreams
  • Sexual problems, including less interest in sex, problems with ejaculation, or problems getting or keeping an erection (see below)
  • Feeling less hungry (see below)
  • Constipation or diarrhea
  • Nausea or vomiting
  • Dry mouth
  • Feeling unusually weak or tired
  • Change in sleep habits, including sleepiness or trouble sleeping
  • Yawning 
  • Shaking 
  • Dizziness 
  • Blurred vision 
  • Sweating 
  • Feeling anxious or nervous 
  • Headache 
  • Fast heart rate

There may be other side effects of venlafaxine that are not listed here. Contact your healthcare provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of venlafaxine?

While less common, the most serious side effects of venlafaxine are described below, along with what to do if they happen.

Severe Allergic Reactions. Venlafaxine may cause allergic reactions, which can be serious. Stop using venlafaxine and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching, skin rash, or pale red bumps on the skin called hives
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Suicidal Thoughts or Actions. Venlafaxine or other antidepressants may increase the risk of suicidal thoughts or actions in a small number of children, teenagers, or young adults in the first few months of taking the medicine or when the dose is changed. Depression or other serious mental health conditions are the most important causes of suicidal thoughts or actions. If you or your child is about to harm themselves, call 911 or call or text 988, the Suicide & Crisis Lifeline. Call your healthcare provider right away if you have any of the following symptoms.

  • New or increased thoughts of suicide or death
  • Suicide attempt
  • New or increased feelings of anxiety, depression, or other unusual changes in your mood or behavior

Serotonin Syndrome. Serotonin syndrome is when there is too much of a substance called serotonin in your body. Venlafaxine can cause serotonin syndrome when it is taken alone or with other medicines that affect serotonin. This condition can be life-threatening. Get emergency help if you have any of the following symptoms of serotonin syndrome.

  • Sweating, fever, or flushing
  • Confusion
  • Feeling agitated or restless
  • Seeing or hearing unusual things
  • Dizziness
  • Fast or racing heartbeat
  • Nausea, vomiting, or diarrhea
  • Muscle twitching, stiffness, or tremor
  • Seizures

Glaucoma. Venlafaxine may cause your pupils to dilate which can increase the pressure inside the eye and cause or worsen narrow-angle glaucoma, which can lead to blindness. Tell your healthcare provider right away if you have any of the following symptoms of glaucoma.

  • Loss of vision
  • Eye pain or redness
  • Severe headache or vomiting
  • Seeing bright, colorful circles around lights (vision halos)

Increased Blood Pressure (Hypertension). Venlafaxine may increase your blood pressure or make it worse if you have a history of high blood pressure. Call your healthcare provider if your blood pressure increases while taking this medicine.

If you measure your blood pressure and the top number (systolic) is 180 mm Hg or higher or the bottom number (diastolic) is 120 mm Hg or higher, get medical attention right away. Increases in blood pressure may not be noticeable but look out for any of the following symptoms of severely high blood pressure.

  • Sudden severe headache
  • Chest pain
  • Dizziness or confusion
  • Trouble breathing
  • Nausea/vomiting
  • Blurry or other changes to vision
  • Anxiety
  • Buzzing in the ears
  • Nosebleed
  • Feeling of skipped heartbeats

Sexual Problems. Taking venlafaxine or another serotonin-norepinephrine reuptake inhibitor (SNRI) may cause sexual problems. Tell your healthcare provider if you have any of the following sexual problems. 

  • Decreased sex drive
  • Delayed ejaculation or unable to have an ejaculation
  • Problems getting or keeping an erection
  • Delayed orgasm or unable to have an orgasm

Changes in Appetite or Growth. Taking venlafaxine or another SNRI may cause changes in appetite or weight. This medicine may also affect growth in terms of height. Children and adolescents will be closely monitored during treatment with venlafaxine. Notify your healthcare provider or your child’s healthcare provider if you notice changes in appetite.

Extremely Elevated Mood (Mania). People with bipolar disorder can have severe high and low moods. The first symptom of bipolar disorder may be depression. People with bipolar disorder who take an antidepressant, such as venlafaxine, may have a higher risk of having mania or a manic episode. Call your healthcare provider right away if you have any of the following symptoms of a manic episode.

  • Dramatic increase in energy
  • Significant trouble sleeping
  • Your thoughts are racing and fast-paced
  • Engaging in reckless behavior
  • Having unusually grand ideas
  • Feeling excessively happy or irritable
  • Talking more or faster than usual

Low Sodium Level (Hyponatremia). Venlafaxine may cause low sodium levels. Call your healthcare provider if you have any of the following symptoms of a low sodium level.

  • Headache
  • Drowsiness
  • Muscle weakness or cramps
  • Nausea, vomiting, or loss of appetite
  • Tiredness or sleepiness
  • Dizziness
  • Weight gain
  • Restlessness or irritability
  • Change in your mental condition such as hallucinations, confusion, decreased awareness, or alertness
  • Seizures

Seizures. Some people who have taken venlafaxine have reported having seizures. There are many different types of seizures and some of them are not easy to recognize. Stop taking venlafaxine and call your healthcare provider if you experience any of the following signs that a seizure is happening or could happen.

  • Muscle twitching, jerking, spasms, tremors, or other uncontrolled movements
  • Stiffening of your arms and legs
  • Feeling anxious, nervous, confused, or a sense of dread
  • Feeling dizzy or lightheaded
  • Falling or losing consciousness

Abnormal Bleeding. People taking venlafaxine or other antidepressants may have an increased risk of bleeding or bruising. You may be at higher risk if you are also taking aspirin, a nonsteroidal anti-inflammatory drug (NSAID), like ibuprofen or naproxen, or a blood thinner such as warfarin (Coumadin, Jantoven), apixaban (Eliquis), or rivaroxaban (Xarelto). Tell your healthcare provider if you notice any changes in how easily you bruise or bleed.

Increased Cholesterol. Venlafaxine may increase your cholesterol levels. Your healthcare provider will monitor your cholesterol levels during treatment with venlafaxine.

Lung Problems. Venlafaxine can cause inflammation in your lungs, also called interstitial lung disease. Tell your healthcare provider if you have trouble breathing. You may also have a cough and/or fever.

Warnings & Precautions

Who should not use venlafaxine?

Allergies to Ingredients. People who are allergic to any of the following should not take venlafaxine.

  • Venlafaxine
  • Effexor
  • Desvenlafaxine
  • Pristiq
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in the specific venlafaxine products they stock.

Drug Interactions. Venlafaxine should not be taken while you are using certain other medicines. Before taking venlafaxine, tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

What should I know about venlafaxine before using it?

Do not take venlafaxine unless it has been prescribed to you by a healthcare provider. Take it as prescribed.

Do not share venlafaxine with other people, even if they have the same condition as you. It may harm them.

Keep venlafaxine out of the reach of children.

Do not divide, chew, crush, or dissolve venlafaxine extended-release tablets or extended-release capsules.

If you cannot swallow the extended-release capsules whole, they may be opened and the entire contents sprinkled on a spoonful of applesauce. Swallow the mixture right away without chewing. Follow with a glass of water to make sure you have swallowed all of the pellets.

Venlafaxine can make you feel tired or affect your thinking and reaction time. Do not drive or do other activities that require alertness and coordination until you know how venlafaxine affects you.

People who are 65 and older can be at greater risk for some side effects from venlafaxine. Talk to your healthcare provider about your risks if you are in this age group.

Do not stop taking venlafaxine without talking to your healthcare provider. Stopping too quickly may cause serious side effects. Call your healthcare provider right away if you have any of the following symptoms.

  • Anxiety, irritability, or high or low mood
  • Feeling restless 
  • Changes in sleep habits
  • Headache
  • Sweating or shaking
  • Nausea
  • Dizziness
  • Electric-shock like feelings
  • Confusion

What should I tell my healthcare provider before using venlafaxine?

Tell your healthcare provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if venlafaxine is right for you.

In particular, make sure that you discuss any of the following.

Current and past health conditions. Tell your healthcare provider if you have any of the following.

  • Liver problems
  • Kidney problems
  • Heart problems
  • Diabetes 
  • Thyroid problems
  • Glaucoma 
  • Bipolar disorder or mania
  • Seizures (or a history of seizures)
  • Low sodium levels in the blood
  • High blood pressure
  • High cholesterol
  • Any bleeding problems

Pregnancy. Taking venlafaxine later in pregnancy may lead to an increased risk of certain problems in your unborn baby. Tell your healthcare provider if you are or plan to become pregnant. Your healthcare provider will advise you if you should take venlafaxine while you are pregnant or trying to become pregnant. If you become pregnant while taking venlafaxine, you can register for the National Pregnancy Registry for Antidepressants by calling 844-405-6185 or at www.womensmentalhealth.org/research/pregnancyregistry/antidepressants. This registry collects safety information about the use of antidepressant medicines during pregnancy.

Breastfeeding. Venlafaxine passes into breast milk. Tell your healthcare provider if you are breastfeeding or plan to breastfeed. Your healthcare provider will advise you if you should take venlafaxine while breastfeeding.

Interactions

Does venlafaxine interact with foods or drinks?

There are no known interactions between venlafaxine and foods or drinks.

Avoid drinking alcohol while taking venlafaxine. The combination can increase sleepiness or affect your alertness or concentration.

Does venlafaxine interact with other medicines (drug interactions)?

Always tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

In particular, make sure that you discuss if you are using any of the following before taking venlafaxine.

  • A monoamine oxidase inhibitor (MAOI) within the past 2 weeks, which is a medicine usually used for depression or Parkinson’s disease
  • A selective serotonin reuptake inhibitor (SSRI) or any other serotonin norepinephrine reuptake inhibitor (SNRI), which are medicines commonly used for anxiety and depression
  • tricyclic antidepressant, such as amitriptyline, nortriptyline, or protriptyline, even if it is not used for depression
  • A type of medicine called a triptan, such as sumatriptan (Imitrex and others), eletriptan (Relpax), and others, which is commonly used to treat migraines
  • St. John’s wort, which is a supplement that may be used to treat depression
  • Lithium, which is a medicine for certain mental health conditions
  • Buspirone, which is a medicine for anxiety
  • An antipsychotic, which is a medicine for certain mental health conditions
  • Amphetamines, such as Adderall, which are used to treat attention deficit hyperactivity disorder (ADHD) and narcolepsy
  • Opioid pain medicines, such as tramadol or fentanyl
  • Any other medicine that causes dizziness and sleepiness, such as prescription pain medicines, sleep medicines, and medicines for anxiety
  • Medicines that affect bleeding, like a nonsteroidal anti-inflammatory drug (NSAID), warfarin, or aspirin
  • Cimetidine (Tagamet HB), which is a medicine used for heartburn
  • Ketoconazole, which is a medicine used for fungal infections

Some other medicines may alter the blood levels of venlafaxine, and vice versa. Venlafaxine interacts with many other medicines. Always tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

This may not be a complete list of medicines that can interact with venlafaxine. Always check with your healthcare provider.

Does Venlafaxine (Effexor) interact with other drugs you are taking?
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Overdose/Missed Dose

What should I do if I accidentally use too much venlafaxine?

If you or someone else has used too much venlafaxine, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of venlafaxine?

If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and only take the next dose. Do not take double or extra doses.

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