Generic Name: venlafaxine (VEN la fax een)
Brand Name: Effexor XR, Effexor
Medically reviewed by Sophia Entringer, PharmD. Last updated on Dec 24, 2020.
What is venlafaxine?
Venlafaxine is an antidepressant belonging to a group of drugs called selective serotonin and norepinephrine reuptake inhibitors (SSNRIs). Venlafaxine affects chemicals in the brain that may be unbalanced in people with depression.
You should not take venlafaxine if you have uncontrolled narrow-angle glaucoma, or if you are being treated with methylene blue injection.
Do not use venlafaxine within 7 days before or 14 days after you have used a MAO inhibitor, such as isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, or tranylcypromine.
Some young people have thoughts about suicide when first taking an antidepressant. Stay alert to changes in your mood or symptoms. Report any new or worsening symptoms to your doctor, such as: mood or behavioral changes, anxiety, panic attacks, trouble sleeping, or if you feel impulsive, irritable, agitated, hostile, aggressive, restless, hyperactive (mentally or physically), more depressed, or have thoughts about suicide or hurting yourself.
Do not stop using venlafaxine without first talking to your doctor.
Do not give this medicine to anyone younger than 18 years old without the advice of a doctor. Venlafaxine is not FDA approved for use in children.
Before taking this medicine
You should not take this medicine if you are allergic to venlafaxine or desvenlafaxine (Pristiq).
Do not use venlafaxine within 7 days before or 14 days after you have used an MAO inhibitor, such as isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, or tranylcypromine. A dangerous drug interaction could occur.
Some medicines can interact with venlafaxine and cause a serious condition called serotonin syndrome. Be sure your doctor knows if you also take opioid medicine, herbal products, or medicine for depression, mental illness, Parkinson's disease, migraine headaches, serious infections, or prevention of nausea and vomiting. Ask your doctor before making any changes in how or when you take your medications.
To make sure venlafaxine is safe for you, tell your doctor if you have ever had:
bipolar disorder (manic depression);
cirrhosis or other liver disease;
heart disease, high blood pressure, high cholesterol;
a thyroid disorder;
a history of seizures;
a bleeding or blood clotting disorder;
low levels of sodium in your blood; or
if you are switching to venlafaxine from another antidepressant.
Some young people have thoughts about suicide when first taking an antidepressant. Your doctor will need to check your progress at regular visits while you are using venlafaxine. Your family or other caregivers should also be alert to changes in your mood or symptoms.
Venlafaxine may cause serious lung problems in a newborn if the mother takes the medicine late in pregnancy (during the third trimester). However, you may have a relapse of depression if you stop taking your antidepressant. Tell your doctor right away if you become pregnant while taking this medicine. Do not start or stop taking this medicine during pregnancy without your doctor's advice.
Venlafaxine can pass into breast milk and may harm a nursing baby. Talk to you doctor before using this drug if breastfeeding.
Venlafaxine is not approved for use by anyone younger than 18 years old.
How should I take venlafaxine?
Take venlafaxine exactly as prescribed by your doctor. Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.
Venlafaxine should be taken with food. Try to take your dose at the same time each day.
Do not crush, chew, break, or open an extended-release tablet or capsule. Swallow it whole.
To make the extended-release capsule easier to swallow, you may open the capsule and sprinkle the medicine into a small amount of applesauce. Swallow all of the mixture without chewing, and do not save any for later use.
It may take several weeks before your symptoms improve. Keep using the medication as directed. Do not stop using venlafaxine without first talking to your doctor. You may have unpleasant side effects if you stop taking this medicine suddenly.
Your blood pressure will need to be checked regularly.
This medicine can cause you to have a false positive drug screening test. If you provide a urine sample for drug screening, tell the laboratory staff that you are taking this medicine.
Store at room temperature away from moisture and heat.
What happens if I miss a dose?
Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.
What happens if I overdose?
Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.
What should I avoid while taking venlafaxine?
Drinking alcohol with this medicine can cause side effects.
Ask your doctor before taking a nonsteroidal anti-inflammatory drug (NSAID) for pain, arthritis, fever, or swelling. This includes aspirin, ibuprofen (Advil, Motrin), naproxen (Aleve), celecoxib (Celebrex), diclofenac, indomethacin, meloxicam, and others. Using an NSAID with venlafaxine may cause you to bruise or bleed easily.
Venlafaxine may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.
Venlafaxine side effects
Get emergency medical help if you have signs of an allergic reaction to venlafaxine: skin rash or hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Report any new or worsening symptoms to your doctor, such as: mood or behavior changes, anxiety, panic attacks, trouble sleeping, or if you feel impulsive, irritable, agitated, hostile, aggressive, restless, hyperactive (mentally or physically), more depressed, or have thoughts about suicide or hurting yourself.
Call your doctor at once if you have:
blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights;
easy bruising or bleeding (nosebleeds, bleeding gums), blood in your urine or stools, coughing up blood;
cough, chest tightness, trouble breathing;
a seizure (convulsions);
low levels of sodium in the body - headache, confusion, slurred speech, severe weakness, vomiting, hallucinations, feeling unsteady, slow breathing; or
severe nervous system reaction - very stiff (rigid) muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, feeling like you might pass out.
Seek medical attention right away if you have symptoms of serotonin syndrome, such as: agitation, hallucinations, fever, sweating, shivering, fast heart rate, muscle stiffness, twitching, loss of coordination, nausea, vomiting, or diarrhea
Common venlafaxine side effects may include:
nausea, vomiting, diarrhea;
changes in appetite or weight;
dry mouth, yawning;
dizziness, headache, anxiety, feeling nervous;
fast heartbeats, tremors or shaking;
sleep problems (insomnia), strange dreams, tired feeling;
increased sweating; or
decreased sex drive, impotence, or difficulty having an orgasm.
This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
What other drugs will affect venlafaxine?
Taking this medicine with other drugs that make you sleepy can worsen this effect. Ask your doctor before taking venlafaxine with a sleeping pill, narcotic pain medicine, muscle relaxer, or medicine for anxiety, depression, or seizures.
Many drugs can interact with venlafaxine. Not all possible interactions are listed here. Tell your doctor about all your current medicines and any you start or stop using, especially:
any other antidepressant;
St. John's wort;
tryptophan (sometimes called L-tryptophan);
a blood thinner - warfarin, Coumadin, Jantoven;
medicine to treat mood disorders, thought disorders, or mental illness - buspirone, lithium, and many others; or
migraine headache medicine - sumatriptan, zolmitriptan, and others.
This list is not complete and many other drugs can interact with venlafaxine. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Give a list of all your medicines to any healthcare provider who treats you.
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.
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.
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