US Brand Names
• Effexor XR
Canadian Brand Names
• Effexor XR
Venlafaxine (ven-la-FAX-een) is used to treat mental depression. It is also used to treat certain anxiety disorders or to relieve the symptoms of anxiety. However, it usually is not used for anxiety or tension caused by the stress of everyday life.
This medicine is available only with your doctor's prescription, in the following dosage forms:
• Extended-release capsules (U.S. and Canada)
• Tablets (U.S. and Canada)
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For venlafaxine, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to venlafaxine. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.
Studies have not been done in pregnant women. However, when pregnant rats were given venlafaxine in doses much larger than the usual human dose, some of their pups died before or soon after birth. Before taking this medicine, make sure your doctor knows if you are pregnant (especially if it is the third trimester) or if you may become pregnant.
This medicine passes into breast milk and may cause unwanted effects. It may be necessary for you to take another medicine or to stop breast-feeding during treatment. Be sure you have discussed the risks and benefits of this medicine with your doctor.
Venlafaxine must be used with caution in children with depression. Studies have shown occurrences of children thinking about suicide or attempting suicide in clinical trials for this medicine. More study is needed to be sure venlafaxine is safe and effective in children.
In studies done to date that have included elderly people, venlafaxine did not cause different side effects or problems in older people than it did in younger adults.
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking venlafaxine, it is especially important that your health care professional know if you are taking the following:
• Buspirone (e.g., BuSpar) or
• Bromocriptine (e.g., Parlodel) or
• Certain tricyclic antidepressants (amitriptyline [e.g., Elavil], clomipramine [e.g., Anafranil], or imipramine [e.g., Tofranil]) or
• Dextromethorphan (cough medicine) or
• Levodopa (e.g., Sinemet) or
• Lithium (e.g., Eskalith) or
• Meperidine (e.g., Demerol) or
• Nefazodone (e.g., Serzone) or
• Pentazocine (e.g., Talwin) or
• Selective serotonin reuptake inhibitors (fluoxetine [e.g., Prozac], fluvoxamine [e.g., Luvox], paroxetine [e.g., Paxil], sertraline [e.g., Zoloft]) or
• Street drugs (LSD, MDMA [e.g., ecstasy], marijuana) or
• Sumatriptan (e.g., Imitrex) or
• Tramadol (e.g., Ultram) or
• Trazodone (e.g., Desyrel) or
• Tryptophan-Using these medicines with venlafaxine may increase the chance of developing a rare, but very serious, unwanted effect known as the serotonin syndrome; symptoms of this syndrome include confusion, diarrhea, fever, poor coordination, restlessness, shivering, sweating, talking or acting with excitement you cannot control, trembling or shaking, or twitching; if you experience these symptoms contact your doctor as soon as possible
• Moclobemide (e.g., Manerex)-Taking moclobemide and venlafaxine together or less than 3 days apart may increase the chance of developing serious unwanted effects, including the serotonin syndrome, and is not recommended
• Monoamine oxidase (MAO) inhibitor activity (isocarboxazid [e.g., Marplan], phenelzine [e.g., Nardil], procarbazine [e.g., Matulane], selegiline [e.g., Eldepryl], tranylcypromine [e.g., Parnate]) Do not take venlafaxine while you are taking or within 2 weeks of taking an MAO inhibitor ; if you do, you may develop confusion, agitation, restlessness, stomach or intestinal symptoms, sudden high body temperature, extremely high blood pressure, and severe convulsions; at least 14 days should be allowed between stopping treatment with an MAO inhibitor and starting treatment with venlafaxine, and at least 7 days should be allowed between stopping treatment with venlafaxine and starting treatment with an MAO inhibitor
Other medical problems
The presence of other medical problems may affect the use of venlafaxine. Make sure you tell your doctor if you have any other medical problems, especially:
• Bipolar disorder (mood disorder with alternating episodes of mania and depression) or risk of-May make condition worse. Your doctor will check you for this condition.
• Brain disease or damage, or mental retardation or
• Seizures (history of)-The risk of seizures may be increased
• Heart disease or
• High or low blood pressure-Venlafaxine may make these conditions worse
• Kidney disease or
• Liver disease-Higher blood levels of venlafaxine may occur, increasing the chance of side effects; your doctor may need to adjust your venlafaxine dose
• Mania (history of)-The risk of developing mania may be increased
• Weight loss-Venlafaxine may cause weight loss; this weight loss is usually small, but if a large weight loss occurs, it may be harmful in some patients
Take this medicine only as directed by your doctor to benefit your condition as much as possible. Do not take more of it, do not take it more often, and do not take it for a longer time than your doctor ordered.
You may have to take venlafaxine for 4 weeks or longer before you begin to feel better . Also, you will probably need to keep taking this medicine for at least 6 months, even if you feel better, to help prevent your depression from returning. Your doctor should check your progress at regular visits during this time.
Venlafaxine should be taken with food or on a full stomach to lessen the chance of stomach upset. However, if your doctor tells you to take the medicine a certain way, take it exactly as directed.
If you are taking the extended-release capsule dosage form, swallow the capsule whole with fluid ; do not break, crush, chew, or place the capsule in liquid.
The dose of venlafaxine will be different for different patients. Follow your doctor's orders or the directions on the label . The following information includes only the average doses of venlafaxine. If your dose is different, do not change it unless your doctor tells you to do so.
The number of capsules or tablets that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on your special needs .
• For mental depression:
o For oral extended-release capsule dosage form:
§ Adults-At first, 75 milligrams (mg) a day, taken in one dose in the morning or evening. Your doctor may increase your dose if needed. However, the dose is usually not more than 225 mg a day.
§ Children-Use and dose must be determined by your doctor.
o For oral tablet dosage form:
§ Adults-At first, a total of 75 mg a day, taken in smaller doses two or three times during the day. Your doctor may increase your dose if needed. However, the dose is usually not more than 375 mg a day.
§ Children up to 18 years of age-Use and dose must be determined by your doctor.
• For anxiety:
o For oral extended-release capsule dosage form:
§ Adults-At first, 75 mg a day, taken in one dose in the morning or evening. Your doctor may increase your dose if needed. However, the dose is usually not more than 225 mg per day.
§ Children-Use and dose must be determined by your doctor.
If you are taking the tablet form of venlafaxine and you miss a dose , take it as soon as possible. However, if it is within 2 hours of your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
If you are taking the extended-release capsule form of venlafaxine and you miss a dose , take it as soon as possible. However, if you do not remember the missed dose until the next day, skip the missed dose and go back to your regular dosing schedule. Do not double doses.
To store this medicine:
• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.
It is important that your doctor check your progress at regular visits, to allow for changes in your dose and to help reduce any side effects.
Tell your doctor right away if you develop any allergic reactions, such as skin rash or hives, while taking venlafaxine .
Venlafaxine may cause some people to be agitated, irritable or display other abnormal behaviors. It may also cause some people to have suicidal thoughts and tendencies or to become more depressed. If you or your caregiver notice any of these adverse effects, tell your doctor right away.
Do not stop taking this medicine without first checking with your doctor. Your doctor may want you to reduce gradually the amount you are taking before stopping completely. This is to decrease the chance of side effects.
It is not known how venlafaxine will interact with alcohol and other central nervous system (CNS) depressants (medicines that may make you drowsy or less alert). Some examples of CNS depressants are antihistamines or medicine for hay fever, other allergies, or colds; sedatives, tranquilizers, or sleeping medicine; prescription pain medicine or narcotics; barbiturates; medicine for seizures; muscle relaxants; or anesthetics, including some dental anesthetics. Check with your doctor before taking any of the above while you are using this medicine.
Venlafaxine may cause some people to become drowsy or have blurred vision. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are not alert or able to see clearly .
Dizziness, lightheadedness, or fainting may occur , especially when you get up from a lying or sitting position. Getting up slowly may help. If this problem continues or gets worse, check with your doctor.
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor as soon as possible if any of the following side effects occur :
Changes in vision, such as blurred vision; decrease in sexual desire or ability; headache.
Chest pain; fast or irregular heartbeat; mood or mental changes; ringing or buzzing in ears.
Convulsions (seizures); itching or skin rash; lightheadedness or fainting, especially when getting up suddenly from a sitting or lying position; lockjaw; menstrual changes; problems in urinating or in holding urine; swelling; talking, feeling, and acting with excitement and activity you cannot control; trouble in breathing.
Symptoms of overdose
Agitation; convulsions (seizures); drowsiness; extreme tiredness or weakness; fast heartbeat; tingling, burning, or prickling sensations; trembling or shaking.
This medicine may also cause the following side effect that your doctor will watch for:
High blood pressure.
Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:
Abnormal dreams; anxiety or nervousness; chills; constipation; diarrhea; dizziness; drowsiness; dryness of mouth; heartburn; increased sweating; loss of appetite; nausea; stuffy or runny nose; stomach pain or gas; tingling, burning, or prickly sensations; trembling or shaking; trouble in sleeping; unusual tiredness or weakness; vomiting; weight loss.
Change in sense of taste; muscle tension; yawning.
After you stop using this medicine, your body may need time to adjust. The length of time this takes depends on the amount of medicine you were using and how long you used it. During this period of time check with your doctor if you notice any of the following side effects:
Actions that are out of control; anxiety; changes in dreaming; continuing ringing or buzzing or other unexplained noise in ears; convulsions; crying; depersonalization; diarrhea; difficulty with coordination; dizziness; dryness of mouth; dysphoria; euphoria; fear; feeling of constant movement of self or surroundings; feeling unwell or unhappy; headache; hearing loss; hyperventilation; increased sweating; irregular heartbeats; irritability; lightheadedness; loss of appetite; loss of bladder control; mental depression; mood or mental changes; muscle spasm or jerking of all extremities; nausea; nervousness; nightmares; paranoia; quick to react or overreact emotionally; rapidly changing moods; restlessness; sensation of spinning; sensory disturbances (including shock-like electrical sensations; shakiness in legs, arms, hands, feet; shaking; shaking of hands or feet; shortness of breath; sleeping or unusual drowsiness; sudden loss of consciousness; talking, feeling, and acting with excitement; trembling or shaking of hands or feet; trouble in sleeping; twitches of the muscle visible under the skin; unusual drowsiness, dullness or feeling of sluggishness; unusual tiredness or weakness; vomiting; weight loss.
Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.
Once a medicine has been approved for marketing for a certain use, experience may show that it is also useful for other medical problems. Although this use is not included in product labeling, venlafaxine is used in certain patients with the following medical condition:
Other than the above information, there is no additional information relating to proper use, precautions, or side effects for these uses.
July 22, 2004