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Effexor

Generic name: venlafaxine [ VEN-la-FAX-een ]
Brand name: Generic only. No brands available.

Antidepressants may increase the risk of suicidal thoughts or actions in children, teenagers, and young adults. However, depression and certain other mental problems may also increase the risk of suicide. Talk with the patient's doctor to be sure that the benefits of using Effexor outweigh the risks.

Families and caregivers must closely watch patients who take Effexor. It is important to keep in close contact with the patient's doctor. Tell the doctor right away if the patient has symptoms like worsened depression, suicidal thoughts, or changes in behavior. Discuss any questions with the patient's doctor.


Effexor is used for:

Treating depression. It may also be used for other conditions as determined by your doctor.

Effexor is a serotonin-norepinephrine reuptake inhibitor (SNRI). It works by restoring the balance of certain natural substances in the brain (serotonin and norepinephrine), which helps to improve certain mood problems.

Do NOT use Effexor if:

  • you are allergic to any ingredient in Effexor
  • you are taking or have taken a monoamine oxidase inhibitor (MAOI) (eg, phenelzine, selegiline) within the last 14 days
  • you are taking linezolid or medicines for weight loss (eg, phentermine)

Contact your doctor or health care provider right away if any of these apply to you.

Before using Effexor:

Some medical conditions may interact with Effexor. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

  • if you are pregnant, planning to become pregnant, or are breast-feeding
  • if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement
  • if you have allergies to medicines, foods, or other substances
  • if you or a family member has a history of bipolar disorder (manic-depression), other mental or mood problems, suicidal thoughts or attempts, or alcohol or substance abuse
  • if you have a history of seizures, heart problems (eg, heart failure, irregular heartbeat), abnormal electrocardiograms (ECGs), a recent heart attack, high blood pressure, high cholesterol, overactive thyroid, liver problems, lung problems, kidney problems, stomach or bowel bleeding, blood or bleeding problems, diabetes, increased eye pressure or glaucoma, nervous system problems, or metabolism problems
  • if you are dehydrated, have low blood sodium levels, or drink alcohol
  • if you will be having electroconvulsive therapy (ECT)
  • if you are taking a medicine that contains methylene blue

Some MEDICINES MAY INTERACT with Effexor. Tell your health care provider if you are taking any other medicines, especially any of the following:

  • Buspirone, fentanyl, linezolid, lithium, MAOIs (eg, phenelzine, selegiline), medicines for weight loss (eg, phentermine), selective serotonin reuptake inhibitors (SSRIs) (eg, fluoxetine), serotonin 5-HT1 receptor agonists (eg, sumatriptan), SNRIs (eg, duloxetine), St. John's wort, tramadol, tricyclic antidepressants (eg, amitriptyline), or tryptophan because severe side effects, such as a reaction that may include fever, rigid muscles, blood pressure changes, mental changes, confusion, irritability, agitation, delirium, and coma, may occur
  • Anticoagulants (eg, warfarin), aspirin, or nonsteroidal anti-inflammatory drugs (NSAIDs) (eg, ibuprofen) because the risk of bleeding, including stomach bleeding, may be increased
  • Diuretics (eg, furosemide, hydrochlorothiazide) because the risk of low blood sodium levels may be increased
  • Azole antifungals (eg, ketoconazole) or cimetidine because they may increase the risk of Effexor's side effects
  • Metoprolol because its effectiveness may be decreased by Effexor

This may not be a complete list of all interactions that may occur. Ask your health care provider if Effexor may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

How to use Effexor:

Use Effexor as directed by your doctor. Check the label on the medicine for exact dosing instructions.

  • Effexor comes with an extra patient information sheet called a Medication Guide. Read it carefully. Read it again each time you get Effexor refilled.
  • Take Effexor by mouth with food.
  • Effexor works best if it is taken at the same time each day.
  • Continue to take Effexor even if you feel well. Do not miss any doses.
  • Do not suddenly stop taking Effexor without checking with your doctor. You may have an increased risk of side effects (eg, mental or mood changes, numbness or tingling of the skin, dizziness, confusion, headache, increased sweating, diarrhea, nausea, vomiting, trouble sleeping, or unusual tiredness. If you need to stop Effexor, your doctor may need to gradually lower your dose.
  • If you miss a dose of Effexor, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.

Ask your health care provider any questions you may have about how to use Effexor.

Important safety information:

  • Effexor may cause drowsiness, dizziness, or blurred vision. These effects may be worse if you take it with alcohol or certain medicines. Use Effexor with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.
  • Do not drink alcohol while you are taking Effexor.
  • Check with your doctor before you use medicines that may cause drowsiness (eg, sleep aids, muscle relaxers) while you are using Effexor without checking with your doctor; it may add to their effects. Ask your pharmacist if you have questions about which medicines may cause drowsiness.
  • Several weeks may pass before your symptoms improve. Do NOT take more than the recommended dose or use for longer than prescribed without checking with your doctor.
  • Children, teenagers, and young adults who take Effexor may be at increased risk for suicidal thoughts or actions. Watch all patients who take Effexor closely. Contact the doctor at once if new, worsened, or sudden symptoms such as depressed mood; anxious, restless, or irritable behavior; panic attacks; or any unusual change in mood or behavior occur. Contact the doctor right away if any signs of suicidal thoughts or actions occur.
  • Serotonin syndrome is a possibly fatal syndrome that can be caused by Effexor. Your risk may be greater if you take Effexor with certain other medicines (eg, "triptans," MAOIs, SSRIs). Symptoms may include agitation; confusion; hallucinations; coma; fever; fast or irregular heartbeat; tremor; excessive sweating; and nausea, vomiting, or diarrhea. Contact your doctor at once if you have any of these symptoms.
  • Tell your doctor or dentist that you take Effexor before you receive any medical or dental care, emergency care, or surgery.
  • If your doctor tells you to stop taking Effexor, you will need to wait for a period of time before beginning to take certain other medicines (eg, MAOIs, nefazodone, thioridazine). Ask your doctor when you should start to take your new medicines after you have stopped taking Effexor.
  • Certain antidepressants, including Effexor, may increase the risk of bleeding. Sometimes bleeding can be life-threatening. Discuss any questions or concern with your doctor.
  • Some people may be at risk for eye problems from Effexor. Your doctor may want you to have an eye exam to see if you are at risk for these eye problems. Call your doctor right away if you have eye pain, vision changes, or swelling or redness in or around the eye.
  • Have your blood pressure checked often. Talk with your doctor.
  • Effexor may interfere with certain lab tests. Be sure your doctor and lab personnel know you are taking Effexor.
  • Lab tests may be performed while you use Effexor. These tests may be used to monitor your condition or check for side effects. Be sure to keep all doctor and lab appointments.
  • Use Effexor with caution in the ELDERLY; they may be more sensitive to its effects, especially low blood sodium levels.
  • Caution is advised when using Effexor in CHILDREN; they may be more sensitive to its effects, especially increased risk of suicidal thoughts or actions.
  • Effexor may cause weight changes and growth changes. CHILDREN and teenagers may need regular weight and growth checks while they take Effexor.
  • PREGNANCY and BREAST-FEEDING: Effexor may cause harm to the fetus if it is used during the last 3 months of pregnancy. If you become pregnant, contact your doctor. You will need to discuss the benefits and risks of using Effexor while you are pregnant. Effexor is found in breast milk. Do not breast-feed while taking Effexor.

Possible side effects of Effexor:

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:

Abnormal dreams; constipation; diarrhea; dizziness; drowsiness; dry mouth; headache; increased sweating; loss of appetite; nausea; nervousness; tiredness; trouble sleeping; vomiting; weakness; weight loss; yawning.

Seek medical attention right away if any of these SEVERE side effects occur:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); black, tarry, or bloody stools; chest pain or discomfort; decreased coordination; decreased sexual desire or ability; decreased urination; fainting; fast or irregular heartbeat; fever, chills, cough, or persistent sore throat; hallucinations; new or worsening mental, mood, or behavior changes (eg, aggressiveness, agitation, anxiety, depression, hostility, impulsiveness, inability to sit still, irritability, panic attacks, or restlessness); persistent trouble sleeping; red, swollen, blistered, or peeling skin; ringing in the ears; seizures; severe stomach pain; severe or persistent headache or dizziness; shortness of breath; significant weight loss; suicidal thoughts or attempts; symptoms of low sodium levels (eg, headache, trouble concentrating, memory problems, confusion, weakness, seizures, unsteadiness); tremor; unusual bruising or bleeding; unusual weakness.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. To report side effects to the appropriate agency, please read the Guide to Reporting Problems to FDA.

If OVERDOSE is suspected:

Contact 1-800-222-1222 (the American Association of Poison Control Centers), your local poison control center, or emergency room immediately.

Proper storage of Effexor:

Store Effexor at room temperature, between 68 and 77 degrees F (20 and 25 degrees C). Store away from heat, moisture, and light. Do not store in the bathroom. Keep Effexor out of the reach of children and away from pets.

General information:

  • If you have any questions about Effexor, please talk with your doctor, pharmacist, or other health care provider.
  • Effexor is to be used only by the patient for whom it is prescribed. Do not share it with other people.
  • If your symptoms do not improve or if they become worse, check with your doctor.
  • Check with your pharmacist about how to dispose of unused medicine.

This information should not be used to decide whether or not to take Effexor or any other medicine. Only your health care provider has the knowledge and training to decide which medicines are right for you. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a brief summary of general information about Effexor. It does NOT include all information about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to Effexor. This information is not specific medical advice and does not replace information you receive from your health care provider. You must talk with your health care provider for complete information about the risks and benefits of using Effexor.

Issue Date: June 3, 2015

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.