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Venlafaxine  (Systemic)

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Brand Names

In the U.S.—

  • Effexor
  • Effexor XR

In Canada—

  • Effexor
  • Effexor XR

Category


Description

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:



Before Using This Medicine

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:

Allergies—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.

Pregnancy—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.

Breast-feeding—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.

Children—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.

Older adults—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.

Other medicines—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:

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:


Proper Use of This Medicine

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.

Dosing—

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.

Missed dose—

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.

Storage—

To store this medicine:


Precautions While Using This Medicine

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.


Side Effects of This Medicine

Side Effects of This Medicine

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:

This medicine may also cause the following side effect that your doctor will watch for:

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:

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:


Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.


Additional Information

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.


Revised: 07/22/2004

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