- What is venlafaxine, and how does it work (mechanism of action)?
- What are the uses for venlafaxine?
- What are the side effects of venlafaxine?
- What is the dosage for venlafaxine?
- Which drugs or supplements interact with venlafaxine?
- Is venlafaxine safe to take if I'm pregnant or breastfeeding?
- What else should know about venafaxine?
What is venlafaxine, and how does it work (mechanism of action)?
Venlafaxine is a selective serotonin and norepinephrine reuptake inhibitor (SNRI) used for treating depression. Other drugs in this class include milnacipran (Savella), duloxetine (Cymbalta), and desvenlafaxine (Pristiq). Venlafaxine affects neurotransmitters, the chemicals that nerves within the brain make and release in order to communicate with one another. Neurotransmitters either travel across the space between nerves, attach to receptors on the surface of nearby nerves, or they attach to receptors on the surface of the nerves that produced them, to be taken up by the nerve and released again (a process referred to as re-uptake).
Many experts believe that an imbalance among neurotransmitters is the cause of depression as well as other psychiatric disorders. Serotonin and norepinephrine are two neurotransmitters released by nerves in the brain. Venlafaxine works by preventing the reuptake of serotonin and epinephrine by nerves after they have been released. Since uptake is an important mechanism for removing released neurotransmitters and terminating their actions on adjacent nerves, the reduced uptake caused by venlafaxine increases the effect of serotonin and norepinephrine in the brain. Venlafaxine is available in an extended release formulation (Effexor XR). The FDA approved venlafaxine in December 1993.
What are the side effects of venlafaxine?
Venlafaxine, like most anti-depressants, can cause:
Other side effects that can occur are:
Increased blood pressure can occur, and blood pressure should be monitored.
Seizures have been reported.
The FDA suggests if anti-depressants are discontinued abruptly, symptoms may occur such as dizziness, headache, nausea, changes in mood, or changes in the sense of smell, taste, etc. (Such symptoms even may occur when even a few doses of anti-depressant are missed.) Therefore, it is generally recommended that the dose of anti-depressant be reduced gradually when therapy is discontinued.
Antidepressants increased the risk of suicidal thinking and behavior (suicidality) in short-term studies in children, adolescents, and young adults with depression and other psychiatric disorders. Anyone considering the use of venlafaxine or any other antidepressant in a child or adolescent must balance this risk with the clinical need. Patients who are started on therapy should be closely observed for clinical worsening, suicidality, or unusual changes in behavior.
What is the dosage for venlafaxine?
Venlafaxine should be taken with food at doses specifically directed by a physician. Individual doses vary greatly among individuals. The anti-depressant effects are not maximal for 1-2 weeks. If discontinued, the dose of venlafaxine should gradually be reduced under the direction of a physician. For patients with difficulty swallowing tablets or capsules, capsules of Effexor XR can be opened and the contents sprinkled on a spoonful of applesauce but removal from the capsule allows immediate release of the drug so it is no longer an extended release drug.
The dose for treatment of depression using the immediate release formulation is 75 to 375 mg daily divided in 2 or 3 doses and given every 8 or 12 hours. The extended release dose is 37.5 mg to 225 mg once daily. Dosing is usually begun with low initial concentrations and adjusted as needed by the treating doctor.
Generalized anxiety and panic disorder are treated with 37.5 mg to 225 mg once daily using the extended release formulation. Social anxiety is treated with 75 mg daily using the extended release formulation.
Latest Depression News
Daily Health News
Which drugs or supplements interact with venlafaxine?
Venlafaxine should not be used in combination with a monoamine oxidase inhibitor (MAOI) such as phenelzine (Nardil), tranylcypromine (Parnate), isocarboxazid (Marplan), and selegiline (Eldepryl), or within 14 days of discontinuing the MAOI. At least 5 days should be allowed after stopping venlafaxine before starting an MAOI. Combinations of SNRIs and MAOIs may lead to serious, sometimes fatal, reactions including very high body temperature, muscle rigidity, rapid fluctuations of heart rate and blood pressure, extreme agitation progressing to delirium, and coma. Similar reactions may occur if venlafaxine is combined with antipsychotics, tricyclic antidepressants or other drugs that affect serotonin in the brain. Examples include tryptophan, sumatriptan (Imitrex), lithium, linezolid (Zyvox), tramadol (Ultram), and St. John's wort.
Combining venlafaxine with aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs), warfarin (Coumadin) or other drugs that are associated with bleeding may increase the risk of bleeding, because venlafaxine is associated with bleeding.
Most medications affecting the brain such as venlafaxine have the potential to slow reflexes or impair judgment. Therefore, caution is advised especially early in the course of treatment.
Safety has not been established in children below the age of 18 years.
Is venlafaxine safe to take if I'm pregnant or breastfeeding?
The effects of venlafaxine on the fetus during pregnancy are unknown.
What else should know about venafaxine?
- Venafaxine is available as:
- Tablets: 25, 37.5, 50, 75, and 100 mg.
- Tablets (Extended Release): 37.5, 75, 150, 225 mg;
- Capsules (Extended Release): 37.5, 75, and 150 mg.
- Store venafaxine in a dry place at 20 C to 25 C (68 F to 77 F).
- Venafaxine is available in generic form. You need a prescription to obtain this drug.
Venlafaxine (venlafaxine, Effexor XR; Effexor has been discontinued in the US) is a drug in the class of drugs called SNRIs (serotonin and norepinephrine reuptake inhibitors) prescribed for the treatment of depression, depression with symptoms of anxiety, generalized anxiety disorder. Effexor XR is prescribed for the treatment of and panic disorder in adults. Side effects, drug interactions, dosage, and pregnancy safety information should be reviewed prior to taking this medication.
Multimedia: Slideshows, Images & Quizzes
Anxiety Disorder Pictures: Symptoms, Panic Attacks, and More with Pictures
Learn about generalized anxiety disorder (GAD). See if your worries are normal or something more by learning about symptoms,...
Schizophrenia: Symptoms, Types, Causes, Treatment
What is schizophrenia? Learn about schizophrenia symptoms, signs, and treatment. Read about schizophrenia types such as paranoid...
Learn to Spot Depression: Symptoms, Warning Signs, Medication
What is depression? Get information on symptoms, signs, tests, and treatments for many types of depression including major...
Depression Myths: Overwork, Recklessness and More in Pictures
Folk remedies and half-truths still prevent many from getting treatment for depression. WebMD's pictures show unusual symptoms in...
17 Everyday Ways to Ease Depression
The right exercise, diet, and activities -- even playing with a pet --can help you recover from depression. Learn simple...
Depression Therapy: Myths, Facts, and More in Pictures
False ideas scare many depression suffers away from therapy and the quick relief and help these pros can provide. Let our experts...
Bipolar Disorder (Mania) Quiz: Test Your Emotional Wellness IQ
Who is at risk for developing bipolar disorder? Are you? Take this Bipolar Disorder Quiz to learn more about bipolar disorder, if...
Depression Quiz: Signs & Symptoms
Many people do not recognize the symptoms and warning signs of depression and depressive disorders in children and adults. With...
Panic Attacks (Panic Disorder) Quiz: Test Your Mental Health IQ
Could you suffer a panic attack? Take this Panic Attacks Quiz to learn causes, symptoms, and treatments for panic disorder. Use...
Healthy Aging: Sneaky Depression Triggers in Pictures
There are many causes and triggers of depression. From too little vitamin B12 to too much time alone, look at these surprising...
Physical Symptoms of Depression in Pictures
Depression can cause physical problems such as insomnia, chest pain, fatigue, headaches, and more. Learn the signs of depression...
Related Disease Conditions
Migraine headache is a type of headache associated with a sensitivity to light, smells, or sounds, eye pain, severe pounding on one side of the head, and sometimes nausea and vomiting. The exact cause of migraine headaches is not known. Triggers for migraine headaches include certain foods, stress, hormonal changes, strong stimuli (loud noises), and oversleeping. Treatment guidelines for migraines include medicine, pain management, diet changes, avoiding foods that trigger migraines, staying hydrated, getting adequate sleep, and exercising regularly. Prevention of migraine triggers include getting regular exercise, drinking water daily, reducing stress, and avoiding trigger foods.
Depression is an illness that involves the body, mood, and thoughts and affects the way a person eats and sleeps, the way one feels about oneself, and the way one thinks about things. The principal types of depression are major depression, dysthymia, and bipolar disease (also called manic-depressive disease).
Hot flashes (or flushing) is the most common symptom experienced by a woman prior to and during the early stages of menopause, and often is described as the feeling of warmth that spreads over the body, often starting at the head accompanied by sweating. Symptoms of hot flashes include flushing, excessive sweating, anxiety, and palpitations.
Anxiety is a feeling of apprehension and fear characterized by symptoms such as trouble concentrating, headaches, sleep problems, and irritability. Anxiety disorders are serious medical illnesses that affect approximately 19 million American adults. Treatment for anxiety may incorporate medications and psychotherapy.
Panic attacks are sudden feelings of terror that strike without warning. These episodes can occur at any time, even during sleep. A person experiencing a panic attack may believe that he or she is having a heart attack or that death is imminent. The fear and terror that a person experiences during a panic attack are not in proportion to the true situation and may be unrelated to what is happening around them. Most people with panic attacks experience several of the following symptoms: racing heartbeat, faintness, dizziness, numbness or tingling in the hands and fingers, chills, chest pains, difficulty breathing, and a feeling of loss or control. There are several treatments for panic attacks.
Post-traumatic Stress Disorder
Post-traumatic stress disorder (PTSD), a psychiatric condition, can develop after any catastrophic life event. Symptoms include nightmares, flashbacks, sweating, rapid heart rate, detachment, amnesia, sleep problems, irritability, and exaggerated startle response. Treatment may involve psychotherapy, group support, and medication.
Obsessive Compulsive Disorder (OCD)
Obsessive-compulsive disorder (OCD) is an anxiety disorder that causes a person to suffer repeated obsessions and compulsions. Symptoms include irresistible impulses despite a person's realization that the thoughts are irrational, excessive hand washing, skin picking, lock checking, or repeatedly rearranging items. People with OCD are more likely to develop trichotillomania, muscle or vocal tics, or an eating disorder. Treatment for OCD includes psychotherapy, behavioral therapy, and medication.
Postherpetic neuralgia (PHN) is a painful complication of shingles. Symptoms include severe pain, itchy skin, and possible weakness or paralysis of the area. There is no treatment for postherpetic neuralgia that is effective for all patients.
Bipolar Disorder vs. Schizophrenia
Bipolar disorder and schizophrenia are mental illnesses that share some risk factors and treatments. Symptoms of bipolar disorder include mood changes and manic and depressive episodes. Symptoms of schizophrenia include unusual behavior, delusions, and hallucinations.
Bipolar disorder (or manic depression) is a mental illness characterized by depression, mania, and severe mood swings. Treatment may incorporate mood-stabilizer medications, antidepressants, and psychotherapy.
Fragile X Syndrome
Fragile X syndrome is the most common inherited form of mental retardation. It's caused by a mutation on the X chromosome. People with Fragile X syndrome suffer from physical, social, emotional, speech, language, sensory, intelligence, and learning impairments. There is no definitive treatment for Fragile X, though there are ways to minimize the symptoms.
Neuropathic pain is a chronic condition that leads to ongoing pain symptoms. Patients can be predisposed to developing neuropathic pain who have conditions such as diabetes, cancer, stroke, HIV, vitamin deficiencies, shingles, and multiple sclerosis. Patient history and nerve testing are used to diagnose neuropathic pain. Antidepressants, antiseizure medications, and other types of medications are used to treat neuropathic pain. Many people with neuropathic pain are able to attain some level of relief.
Depression in teenagers may be caused by many factors. Symptoms of teen depression include apathy, irresponsible behavior, sadness, sudden drop in grades, withdrawal from friends, and alcohol and drug use. Treatment of depression in adolescents may involve psychotherapy and medications.
Schizotypal Personality Disorder
Schizotypal personality disorder is characterized by odd behaviors, feelings, perceptions, and ways of relating to others that interfere with one's ability to function. Medication and psychotherapy can help the sufferer to manage their symptoms.
Narcolepsy (Definition, Symptoms, Treatment, Medication)
Causes of narcolepsy, a chronic disease of the central nervous system, have not been fully determined. Some theories include abnormalities in hypocretin neurons in the brain or an autoimmune disorder. Symptoms of narcolepsy include: excessive daytime sleepiness, cataplexy, hypnagogic hallucinations, sleep paralysis, disturbed nocturnal sleep, and automatic behavior. Diagnosis of narcolepsy is based on a clinical evaluation, specific questionnaires, sleep logs or diaries, and the results of sleep laboratory tests. Treatments of narcolepsy symptoms include medication and lifestyle changes.
Duck syndrome is a situation initially coined at Stanford University whereby a college student may seem to be calm on the surface when actually he or she is frantically struggling to stay above water to meet the demands of student life.
Mental health is an optimal way of thinking, relating to others, and feeling. All of the diagnosable mental disorders fall under the umbrella of mental illness. Depression, anxiety, and substance-abuse disorders are common types of mental illness. Symptoms and signs of mental illness include irritability, moodiness, insomnia, headaches, and sadness. Treatment may involve psychotherapy and medication.
Dysthymia is a less severe form of chronic depression. Symptoms and signs include insomnia, suicidal thoughts, guilt, empty feeling, loss of energy, helplessness, sluggishness, and persistent aches and pains. Treatment may involve psychotherapy, electroconvulsive therapy, and antidepressants.
People with bulimia nervosa, an eating disorder that involves episodes of bingeing and purging, experience symptoms and signs such as deteriorating teeth, sore throat, constipation, thinning hair, and dehydration. Treatment of bulimia may involve cognitive behavior therapy, family therapy, nutritional counseling, and medication.
Postpartum depression is a form of depression that occurs within a year after delivery. It is thought that rapid hormone changes after childbirth may lead to depression. Symptoms of postpartum depression include crying a lot, headaches, chest pains, eating too little or too much, sleeping too little or too much, withdrawal from friends and family, and feeling irritable, sad, hopeless, worthless, guilty, and overwhelmed. Treatment typically involves talk therapy and medication.
Depression in the Elderly
Depression in the elderly is very common. That doesn't mean, though, it's normal. Treatment may involve antidepressants, psychotherapy, or electroconvulsive therapy.
Treatment & Diagnosis
- Mood Swings
- Hot Flashes
- Poor Hygiene
- Unusual Behavior
- Social Isolation
- Inability to Regulate Emotions
- Bipolar Disorder
- Obsessive-Compulsive Disorder (OCD)
- Panic Attack
- Generalized Anxiety Disorder
- Doctor: Checklist to Take To Your Doctor's Appointment
- Bulimia Nervosa
- Postherpetic Neuralgia
- Depression FAQs
- Panic Attacks Disorder FAQs
- Bipolar Disorder Mania FAQs
- How To Reduce Your Medication Costs
- Pharmacy Visit, How To Get The Most Out of Your Visit
- Indications for Drugs: Approved vs. Non-approved
- Drugs: Buying Prescription Drugs Online Safely
- Drugs: The Most Common Medication Errors
- Medication Disposal
- Dangers of Mixing Medications
- Catherine Zeta-Jones: A Case of Bipolar II Disorder
- Generic Drugs, Are They as Good as Brand-Names?
Medications & Supplements
- Anxiolytics (for Anxiety) Drug Class Side Effects
- Drugs: Questions to Ask Your Doctor or Pharmacist about Your Drugs
- Cymbalta (duloxetine)
- Drug Interactions
- Cymbalta (duloxetine) vs. Effexor (XR, venlafaxine) Differences in Uses, Dose, and Withdrawal
- Side Effects of Effexor (venlafaxine)
- Savella (milnacipran)
Prevention & Wellness
- What Drugs Work Best for Diabetic Nerve Pain?
- 'Off-Label' Antidepressants Common, But Where's the Evidence?
- Study Questions Use of Antidepressants for Children, Teens
- Did Studies Lack Key Data on Link Between Antidepressants, Youth Suicides?
- Certain Antidepressants May Be Linked to Bipolar Disorder: Study
- This Treatment May Help Depression in Older People
- More Than Half of Women Have Hot Flashes for at Least 7 Years
- Weight Gain From Antidepressants Is Minimal, Study Suggests
- Antidepressant Eases Menopause-Related Symptoms, Study Finds
- Pfizer Recalls Effexor Antidepressant
- Antidepressants in Pregnancy Tied to Slight Risk of Lung Disorder in Babies
- Experts Lay Out Options for Menopause Symptoms
- Usual 'Hot Flash' Therapies Don't Help Prostate Cancer Patients: Study
- Antidepressants Aid Depressed Parkinson's Patients
- Menopause May Cost Women Sick Days
- Antidepressants May Not Raise Suicide Risk in Youth: Study
- Newer Antidepressants Work Equally Well, Study Finds
- Depression Rising, but Psychotherapy Declines
- Cataracts From Antidepressants?
Health Solutions From Our Sponsors
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.