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What is Effexor?

Effexor (generic: venlafaxine) is one of the newer medications available to treat depression. Structurally different from other antidepressants, it affects two neurotransmitters (chemical messengers to the brain) involved in depression: serotonin and norepinephrine. Approved for use in the United States at the end of 1993, its novel chemical action and low incidence of side effects make it a significant addition to the range of medications used to treat depression.

How is Effexor different from other antidepressants?

Effexor is a chemically unique antidepressant medication. Like the newer class of antidepressants known as selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine (Prozac) and setraline (Zoloft), it affects the absorption of serotonin. In addition, Effexor acts on the norepinephrine system. No other available medication affects both neurotransmitters without causing the side effects of the older tricyclic antidepressants.

Are there other advantages of Effexor?

Effexor is less likely to induce seizures, to have toxic effects on the heart, and to cause lethal reactions.

For what kind of patient would Effexor be appropriate?

Effexor is recognized as a front line option (that is, first time medication for patients who have recently become ill with depression, whether they are hospitalized or treated on an outpatient basis. It can also be useful for patients who have had long-standing depressive illness and have not responded adequately to previous treatments. Almost 40 percent of so-called refractory patients (those who have not had positive results from past treatment) have had success with Effexor. Patients who have benefited from other antidepressants but have had less than complete success may want to discuss switching to Effexor with their doctors.

What about side effects?

Relatively few side effects have been reported with Effexor. Those that have been noted are dose-related; that is, side effects increase as the dose increases. Very few patients have had to discontinue the medication because of side effects.

The most common minor side effects during clinical trials include short-term nausea (which can be reduced by taking the medication with food), sleepiness, dry mouth, dizziness, constipation, nervousness, sweating, weakness, ejaculation/orgasm problems, and loss of appetite.

A small percentage (about five percent) of patients, usually those taking higher doses, will develop elevated blood pressure. Therefore, patients taking Effexor should have their blood pressure checked regularly. Some agitation has been noticed at higher dosages.

How long does it take to work?

Like most other medications used for depression, Effexor may take several weeks before it is fully effective. It is important to give the medication sufficient time before judging whether it will work for a given person. There is evidence, however, that Effexor may take effect more quickly than other antidepressants.

Can Effexor be taken with other medications?

Effexor does not interact significantly with many other medications, including lithium, diazepam (Valium), and cimetidine (Tagamet, an anti-ulcer medication). However, patients taking cimetidine who have high blood pressure or liver disease or are elderly should use caution in taking Effexor because the interaction can be more pronounced when these disorders are present.

Effexor definitely should not be taken at the same time as the MAOIs (such as Parnate or Nardil). Interactions with these compounds could be lethal. Patients who have been taking an MAOI and are switching to Effexor must allow sufficient time (usually 14 days) for the MAOI to clear out of the body. The same time should be allowed if changing from Effexor to an MAOI. However, switching from Effexor to other medications is easy because Effexor is quickly removed from the body.

What is the standard dose?

The dose range is generally between 75 and 375 mg per day. The average effective dose is about 125 to 150 mg per day. Higher doses are necessary for sicker patients. It is recommended that the total dose be divided into two or three doses per day and taken with food. Dosage adjustments for elderly people are not usually necessary.

Will Effexor work for everyone?

No. Everyone responds to medications differently. Effexor will work well for some people, and not so well for others. It is important to give the medication a trial of several weeks and to be in close communication with your doctor about signs of effectiveness, side effects, and personal factors affecting one's response to the medication.