Uses
This medication is used to treat certain mental/mood disorders (such as depression, anxiety, panic attacks, and social anxiety disorder). Venlafaxine belongs to a class of drugs known as serotonin-norepinephrine reuptake inhibitors (SNRIs). It works by helping to restore the balance of certain natural substances (serotonin and norepinephrine) in the brain.
Other Uses
This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional. Use this drug for a condition that is listed in this section only if it has been so prescribed by your health care professional.
This drug may also be used for hot flashes that occur with menopause. It may also be used for nerve pain.
How To Use
Read the Medication Guide and, if available, the Patient Information Leaflet provided by your pharmacist before you start using venlafaxine and each time you get a refill. If you have any questions, ask your doctor or pharmacist.
Take this medication by mouth as directed by your doctor, usually once daily with food, either in the morning or evening.
Do not crush, chew, or dissolve this medication. Doing so can release all of the drug at once, increasing the risk of side effects. Swallow whole without crushing or chewing.
If you are taking the capsules, swallow them whole. If you have trouble swallowing the capsules whole, you may open the capsule and sprinkle the contents onto a spoonful of applesauce. Swallow all of the mixture right away without chewing. Drink a glass of water after each dose.
The dosage is based on your medical condition and response to treatment. To reduce your risk of side effects, your doctor may direct you to start this medication at a low dose and gradually increase your dose. Follow your doctor's instructions carefully. Take this medication regularly to get the most benefit from it. To help you remember, take it at the same time each day.
Keep taking this medication even if you feel well. Do not stop taking this medication without consulting your doctor. Some conditions may become worse when this drug is suddenly stopped. Also, you may experience symptoms such as confusion, mood swings, blurred vision, headache, tiredness, sleep changes, and brief feelings similar to electric shock. Your dose may need to be gradually decreased to reduce side effects. Report any new or worsening symptoms right away.
It may take several weeks to feel the benefit of this medication. Tell your doctor if your condition lasts or gets worse.
Side Effects
See also Warning section.
Nausea, drowsiness, dizziness, dry mouth, constipation, loss of appetite, blurred vision, nervousness, trouble sleeping, unusual sweating, or yawning may occur. If any of these effects last or get worse, tell your doctor promptly.
Remember that this medication has been prescribed because your doctor 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.
This medication may raise your blood pressure. Check your blood pressure regularly and tell your doctor if the results are high.
Tell your doctor right away if you have any serious side effects, including:
- easy bleeding/bruising
- decreased interest in sex
- changes in sexual ability
- muscle cramps/weakness
- shaking (tremor)
Get medical help right away if you have any very serious side effects, including:
- cough that doesn't go away
- shortness of breath
- chest pain
- severe/pounding headache
- black stools
- vomit that looks like coffee grounds
- eye pain/swelling/redness
- widened pupils
- vision changes (such as seeing rainbows around lights at night)
- seizure
This medication may increase serotonin and rarely cause a very serious condition called serotonin syndrome/toxicity. The risk increases if you are also taking other drugs that increase serotonin, so tell your doctor or pharmacist of all the drugs you take (see Drug Interactions section). Get medical help right away if you develop some of the following symptoms:
- fast heartbeat
- hallucinations
- loss of coordination
- severe dizziness
- severe nausea/vomiting/diarrhea
- twitching muscles
- unexplained fever
- unusual agitation/restlessness
A very serious allergic reaction to this drug is rare. However, get medical help right away 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 or at www.fda.gov/medwatch.
In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
Precautions
Before taking venlafaxine, tell your doctor or pharmacist if you are allergic to it; or to desvenlafaxine; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.
Before using this medication, tell your doctor or pharmacist your medical history, especially of:
- bleeding problems
- personal or family history of glaucoma (angle-closure type)
- high blood pressure
- heart problems (such as heart failure, previous heart attack)
- high cholesterol
- kidney disease
- liver disease
- seizure disorder
- thyroid disease
This drug may make you dizzy or drowsy or blur your vision. Alcohol or marijuana (cannabis) can make you more dizzy or drowsy. Do not drive, use machinery, or do anything that needs alertness or clear vision until you can do it safely. Avoid alcoholic beverages. Talk to your doctor if you are using marijuana (cannabis).
Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).
Older adults may be more sensitive to the side effects of this drug, especially dizziness when standing. Older adults may also be more likely to develop a type of salt imbalance (hyponatremia), especially if they are taking "water pills" (diuretics). Dizziness and salt imbalance can increase the risk of falling. Older adults may also be at greater risk for bleeding while using this drug.
Children may be more sensitive to the side effects of the drug, especially loss of appetite and weight loss. Monitor weight and height in children who are taking this drug.
During pregnancy, this medication should be used only when clearly needed. It may harm an unborn baby. Also, babies born to mothers who have used this drug during the last 3 months of pregnancy may rarely 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 mental/mood problems (such as depression, anxiety, panic attacks) 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 drug passes into breast milk and may have undesirable effects on a nursing infant. Consult your doctor before breast-feeding.
Drug Interactions
Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.
Some products that may interact with this drug are:
- other drugs that can cause bleeding/bruising (including antiplatelet drugs such as clopidogrel, NSAIDs such as ibuprofen/naproxen, "blood thinners" such as dabigatran/warfarin)
Aspirin can increase the risk of bleeding when used with this medication. However, if your doctor has directed you to take low-dose aspirin for heart attack or stroke prevention (usually 81-162 milligrams a day), you should continue taking it unless your doctor instructs you otherwise. Ask your doctor or pharmacist for more details.
Taking MAO inhibitors with this medication may cause a serious (possibly fatal) drug interaction. Avoid taking MAO inhibitors (isocarboxazid, linezolid, metaxalone, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, safinamide, selegiline, tranylcypromine) during treatment with this medication. Most MAO inhibitors should also not be taken for two weeks before and at least 7 days after treatment with this medication. Ask your doctor when to start or stop taking this medication.
The risk of serotonin syndrome/toxicity increases if you are also taking other drugs that increase serotonin. Examples include street drugs such as MDMA/"ecstasy," St. John's wort, certain antidepressants (including SSRIs such as fluoxetine/paroxetine, other SNRIs such as duloxetine/milnacipran), tryptophan, among others. The risk of serotonin syndrome/toxicity may be more likely when you start or increase the dose of these drugs.
Tell your doctor or pharmacist if you are taking other products that cause drowsiness such as opioid pain or cough relievers (such as codeine, hydrocodone), alcohol, marijuana (cannabis), drugs for sleep or anxiety (such as alprazolam, lorazepam, zolpidem), muscle relaxants (such as carisoprodol, cyclobenzaprine), or antihistamines (such as cetirizine, diphenhydramine).
Check the labels on all your medicines (such as allergy or cough-and-cold products) because they may contain ingredients that cause drowsiness. Ask your pharmacist about using those products safely.
Venlafaxine is very similar to desvenlafaxine. Do not take medications containing desvenlafaxine while using venlafaxine.
This medication may interfere with certain lab tests (including urine tests for amphetamines), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.
Overdose
If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call their local poison control center at 1-800-222-1222. Alberta residents can call PADIS (Poison and Drug Information Service) 24 hours a day at 1-800-332-1414. Canada residents can call a provincial poison control center. Symptoms of overdose may include: severe drowsiness, seizures, fast/irregular heartbeat.
Notes
Do not share this medication with others.
Lab and/or medical tests (such as blood pressure, cholesterol) should be done while you are taking this medication. Keep all medical and lab appointments. Consult your doctor for more details.
Missed Dose
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. Take your next dose at the regular time. Do not double the dose to catch up.
If you have questions about missing a dose or you don't have more medication, contact your healthcare provider or pharmacist.
Storage
Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications 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.