Effexor (venlafaxine) is an antidepressant in a group of drugs called selective serotonin and norepinephrine reuptake inhibitors (SSNRIs). Effexor affects chemicals in the brain that may be unbalanced in people with depression. Effexor may also be used for purposes not listed in this medication guide.
USES: Effexor is used to treat depression. It may improve your mood and energy level, and may help restore your interest in daily living. Effexor is known as a serotonin-norepinephrine reuptake inhibitor (SNRI). 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 medication may also be used to treat anxiety, panic attacks, and nerve pain. It may also be used to treat hot flashes that occur with menopause.
Read the Medication Guide provided by your pharmacist before you start using Effexor 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 2 to 3 times daily with food. 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 times each day. It is important to continue taking this medication as prescribed 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, 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 immediately. It may take several weeks to feel the benefit of this medication. Tell your doctor if your condition persists or worsens.
Get emergency medical help if you have any of these signs of an allergic reaction: 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 a serious side effect such as: seizure (convulsions); very stiff (rigid) muscles, high fever, sweating, confusion, fast or uneven heartbeats, tremors, feeling like you might pass out; agitation, hallucinations, fever, fast heart rate, overactive reflexes, nausea, vomiting, diarrhea, loss of coordination; headache, trouble concentrating, memory problems, weakness, feeling unsteady, confusion, hallucinations, fainting, shallow breathing or breathing that stops; cough, chest tightness, trouble breathing; or easy bruising. Less serious side effects may include: drowsiness, dizziness, feeling nervous; strange dreams; increased sweating; blurred vision; dry mouth; changes in appetite or weight; mild nausea, constipation; or decreased sex drive, impotence, or difficulty having an orgasm.
Discontinuation symptoms have been systematically evaluated in patients taking Effexor, to include prospective analyses of clinical trials in Generalized Anxiety Disorder and retrospective surveys of trials in major depressive disorder. Abrupt discontinuation or dose reduction of Effexor at various doses has been found to be associated with the appearance of new symptoms, the frequency of which increased with increased dose level and with longer duration of treatment. Reported symptoms include agitation, anorexia, anxiety, confusion, impaired coordination and balance, diarrhea, dizziness, dry mouth, dysphoric mood, fasciculation, fatigue, flu-like symptoms, headaches, hypomania, insomnia, nausea, nervousness, nightmares, sensory disturbances (including shock-like electrical sensations), somnolence, sweating, tremor, vertigo, and vomiting. During marketing of Effexor, other SNRIs (Serotonin and Norepinephrine Reuptake Inhibitors), and SSRIs (Selective Serotonin Reuptake Inhibitors), there have been spontaneous reports of adverse events occurring upon discontinuation of these drugs, particularly when abrupt, including the following: dysphoric mood, irritability, agitation, dizziness, sensory disturbances (e.g. paresthesias such as electric shock sensations), anxiety, confusion, headache, lethargy, emotional lability, insomnia, hypomania, tinnitus, and seizures. While these events are generally self-limiting, there have been reports of serious discontinuation symptoms.
As with all drugs, the potential for interaction by a variety of mechanisms is a possibility. Alcohol Cimetidine Diazepam Haloperidol Lithium Drugs Highly Bound to Plasma Protein Drugs that Interfere with Hemostasis (e.g., NSAIDs, Aspirin, and Warfarin) Drugs that Inhibit Cytochrome P450 Isoenzymes Ketoconazole Drugs Metabolized by Cytochrome P450 Isoenzymes CNS-Active Drugs