Antidepressant medications are used to treat a variety of conditions, including depression and other mental/mood disorders. These medications can help prevent suicidal thoughts/attempts and provide other important benefits. However, studies have shown that a small number of people (especially people younger than 25) who take antidepressants for any condition may experience worsening depression, other mental/mood symptoms, or suicidal thoughts/attempts. Therefore, it is very important to talk with the doctor about the risks and benefits of antidepressant medication (especially for people younger than 25), even if treatment is not for a mental/mood condition.

Tell the doctor immediately if you notice worsening depression/other psychiatric conditions, unusual behavior changes (including possible suicidal thoughts/attempts), or other mental/mood changes (including new/worsening anxiety, panic attacks, trouble sleeping, irritability, hostile/angry feelings, impulsive actions, severe restlessness, very rapid speech). Be especially watchful for these symptoms when a new antidepressant is started or when the dose is changed.

Venlafaxine is an antidepressant (serotonin-norepinephrine reuptake inhibitor type-SNRI) used in the treatment of depression, anxiety, and panic attacks. It works by restoring the balance of natural substances (neurotransmitters such as serotonin and norepinephrine) in the brain. Venlafaxine may improve your mood, feelings of well-being, and energy level and decrease nervousness and the number of panic attacks you may have.

Read the Medication Guide provided by your pharmacist before you start using venlafaxine and each time you get a refill. If you have any questions, consult your doctor or pharmacist.

Take this medication with food, usually once daily or as directed by your doctor. Dosage is based on your medical condition and response to treatment.

Swallow the medication whole. Do not crush, break, or chew the medication, and do not dissolve it in water. Doing so can release all of the drug at once, increasing the risk of side effects. If you have trouble swallowing this medication whole, and you are taking the capsules, you may open the capsule and sprinkle the contents onto a spoonful of applesauce. Swallow all of the mixture immediately without chewing. Drink a glass of water after each dose.

To reduce your risk of side effects, your doctor may direct you to start taking this drug at a low dose and gradually increase your dose. Follow your doctor's instructions carefully. Do not take more or less medication or take it more frequently than prescribed. Your condition will not improve any faster, and your risk of side effects will increase. Use this medication regularly in order to get the most benefit from it. To help you remember, use it at the same time each day.

It is important to continue taking this medication even if you feel well. Do not stop taking this medication without consulting your doctor. Some conditions may become worse when the drug is suddenly stopped. Your dose may need to be gradually decreased.

This medication may cause withdrawal reactions, especially if it has been used regularly for a long time or in high doses. In such cases, withdrawal symptoms (such as nausea, vomiting, headache, numbness, tingling, nightmares) may occur if you suddenly stop using this medication. To prevent withdrawal reactions, your doctor may reduce your dose gradually. Consult your doctor or pharmacist for more details, and report any withdrawal reactions immediately.

It may take several weeks to feel the full benefit of this medication. Tell your doctor if your condition persists or worsens.

See also Warning section.

Headache, drowsiness, dizziness, nausea, weakness, dry mouth, constipation, loss of appetite, weight loss, blurred vision, tiredness, nervousness, trouble sleeping, sweating, or yawning may occur. If any of these effects persist or worsen, tell your doctor promptly.

If you are using the tablet form of this medication, an empty tablet shell may appear in your stool. This effect is harmless because your body has already absorbed the medication.

Venlafaxine may increase blood pressure. Your blood pressure should be checked regularly while you are taking this medication.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Tell your doctor immediately if any of these unlikely but serious side effects occur: severe/pounding headache, unusual or severe mental/mood changes (e.g., extreme anxiety, unusual high energy/excitement, rare thoughts of suicide), shakiness (tremor), decreased interest in sex, changes in sexual ability, difficulty urinating, change in the amount of urine.

Tell your doctor immediately if any of these rare but very serious side effects occur: stomach/abdominal pain, chest pain, persistent cough, shortness of breath, bloody/black/tarry stools, vomit that looks like coffee grounds, easy bruising/bleeding, fast/irregular/pounding heartbeat, muscle weakness/cramps, yellowing eyes/skin, dark urine, seizures, unusual tiredness.

This medication may rarely cause a very serious condition called serotonin syndrome. The risk increases when this medication is used with certain other drugs such as "triptans" used to treat migraine headaches (e.g., sumatriptan, eletriptan), certain antidepressants including SSRIs (e.g., citalopram, paroxetine) and other SNRIs (e.g., duloxetine), lithium, tramadol, tryptophan, or a certain drug to treat obesity (sibutramine). See also Drug Interactions section. Before taking this drug, tell your doctor if you take any of these medications. Serotonin syndrome may be more likely when you start or increase the dose of any of these medications. Seek immediate medical attention if you develop some of the following symptoms: hallucinations, fainting, restlessness, loss of coordination, fast heartbeat, severe dizziness, unexplained fever, severe nausea/vomiting/diarrhea, twitchy muscles.

For males, in the very unlikely event you have a painful or prolonged erection lasting 4 or more hours, stop using this drug and seek immediate medical attention, or permanent problems could occur.

A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before taking venlafaxine, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies.

Before using this medication, tell your doctor or pharmacist your medical history, especially of: personal or family history of psychiatric disorders (e.g., bipolar/manic-depressive disorder), personal or family history of suicide attempts, bleeding problems, severe loss of body water (dehydration), glaucoma, high blood pressure, heart problems (e.g., chest pain, irregular heartbeat, heart attack), high cholesterol, kidney disease, liver disease, seizure disorder, history of stroke, thyroid problems, low sodium in the blood (e.g., hyponatremia).

Venlafaxine may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can infrequently result in serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that require immediate medical attention. The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may affect the heart rhythm (see also Drug Interactions section). Before using venlafaxine, tell your doctor or pharmacist if you have any of the following conditions: certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG), family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death).

Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/"water pills") or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using venlafaxine safely.

This drug may make you dizzy or drowsy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Avoid alcoholic beverages.

Caution is advised when using this medication in the elderly because they may be more sensitive to its effects. The elderly are more likely to lose too much salt (hyponatremia), especially if they are also taking "water pills" (diuretics) with this medication.

Caution is advised when using this drug in children because it may affect weight, growth rate, and final height. Consult your doctor or pharmacist for more details.

This medication is not recommended for use during pregnancy. It may harm an unborn baby. Also, babies born to mothers who have used this drug during the last 3 months of pregnancy may infrequently develop withdrawal symptoms such as feeding/breathing difficulties, seizures, muscle stiffness, or constant crying. If you notice any of these symptoms in your newborn, tell the doctor promptly.

Since untreated depression can be a serious condition, do not stop taking this medication unless directed by your doctor. If you are planning pregnancy, become pregnant, or think you may be pregnant, immediately discuss the benefits and risks of using this medication during pregnancy with your doctor.

This medication passes into breast milk and may have undesirable effects on a nursing infant. Breast-feeding is not recommended while using this drug. Consult your doctor before breast-feeding.

Your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor or pharmacist first.

Taking certain medications with this product could result in serious (rarely fatal) drug interactions. Avoid taking MAO inhibitors (e.g., furazolidone, isocarboxazid, linezolid, moclobemide, phenelzine, procarbazine, rasagiline, selegiline, tranylcypromine) with venlafaxine for 2 weeks before treatment, during treatment, and at least 7 days after your last dose of venlafaxine. Consult your doctor or pharmacist for more information.

This drug should also not be used with the following medications because very serious (possibly fatal) interactions may occur: weight loss drugs (e.g., sibutramine, phentermine), tryptophan.

If you are currently using any of these medications, tell your doctor or pharmacist before starting venlafaxine.

Many drugs besides venlafaxine may affect the heart rhythm (QT prolongation), including amiodarone, dofetilide, pimozide, procainamide, quinidine, sotalol, macrolide antibiotics (such as erythromycin), thioridazine, among others. Therefore, before using venlafaxine, report all medications you are currently using to your doctor or pharmacist.

Before using this medication, tell your doctor or pharmacist of all prescription and nonprescription/herbal products you may use, especially of: drugs removed from your body by certain liver enzymes (e.g., antipsychotics such as clozapine/ haloperidol, HIV medications such as indinavir, tricyclic antidepressants-TCAs such as desipramine), drugs affecting liver enzymes that remove venlafaxine from your body (e.g., cimetidine, azole antifungals such as ketoconazole, itraconazole), drugs that can cause bleeding/bruising (e.g., aspirin, antiplatelet drugs such as clopidogrel, NSAIDs such as ibuprofen, "blood thinners" such as heparin/warfarin).

Aspirin can increase the risk of bleeding when used with this medication (see above). If your doctor has directed you to take low-dose aspirin for heart attack or stroke prevention (usually at dosages of 81-325 milligrams a day), you should continue taking it unless your doctor instructs you otherwise. Discuss the risks and benefits with your doctor.

Also tell your doctor if you take any other drugs that increase serotonin, such as buspirone, dextromethorphan, lithium, meperidine, propoxyphene, SSRIs, other SNRIs, St. John's wort, drugs used to treat migraines such as "triptans" and dihydroergotamine, street drugs such as MDMA/"ecstasy," amphetamine. (See also Side Effects section.)

Tell your doctor or pharmacist if you also take drugs that cause drowsiness such as: certain antihistamines (e.g., diphenhydramine), anti-seizure drugs (e.g., carbamazepine), medicine for sleep or anxiety (e.g., alprazolam, diazepam, zolpidem), muscle relaxants, narcotic pain relievers (e.g., codeine), psychiatric medicines (e.g., chlorpromazine, risperidone, amitriptyline, trazodone). Check the labels on all your medicines (e.g., allergy, cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using these products safely.

Cimetidine is a nonprescription drug that is commonly used to treat extra stomach acid. Because it may cause undesirable interactions when used with venlafaxine, ask your pharmacist about other products to treat stomach acid.

This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist.

If overdose is suspected, contact your local poison control center or emergency room immediately. US residents can call the US National Poison Hotline at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: severe drowsiness, seizures, fast/irregular heartbeat.

Do not share this medication with others.

Psychiatric/medical check-ups or lab tests (e.g., blood pressure, cholesterol, growth monitoring in children) should be done periodically to monitor your progress or check for side effects. Consult your doctor for more details.

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

Store at room temperature between 68-77 degrees F (20-25 degrees C) away from light and moisture. Different brands of this medication may have different storage needs. Check the product package for instructions on how to store your brand, or ask your pharmacist. Do not store in the bathroom. Keep all medicines away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.

Information last revised July 2009 Copyright(c) 2009 First DataBank, Inc.