What is Zoloft?

Zoloft (generic: sertraline hydrochloride) is one of the new anti-depressant medications known as SSRIs (selective serotonin reuptake inhibitors). Like other medications in this class (such as Prozac and Paxil), Zoloft relieves symptoms of depression without the side effects that many people experience with the older tricyclic antidepressants and MAO inhibitors.

What condition does Zoloft treat?

Zoloft is used to treat symptoms of major depressive illness (including bipolar disorder or manic depression). Major depression is a serious medical illness causing mood and physiological changes that significantly interfere with a person's daily functioning. A persistent sad or empty mood accompanies changes in appetite, sleep, and activity level; loss of interest in usual activities, decrease in sexual desire, difficulty concentrating and remembering, slowed thinking and movement, feelings of hopelessness, worthlessness and guilt; and sometimes suicidal thoughts and actions.

Usually several of these symptoms must be present for at least two weeks for a diagnosis of depression to be made. Zoloft has also been shown effective in relieving anxiety, insomnia, and psychomotor agitation that sometimes accompany depression.

How does Zoloft work?

Depressive symptoms are the result of a biochemical imbalance in the brain, a disturbance in the brain's chemical messengers called neurotransmitters. Zoloft acts on the neurotransmitter serotonin, allowing electrical messages to be processed more smoothly and efficiently. This helps relieve symptoms of depression.

Is Zoloft better than other medications for depression? How does one know if Zoloft will be the right medication?

Like other medications in its class, Zoloft relieves depressive symptoms while producing fewer side effects than other classes of antidepressant medication. Usually the side effects that are experienced are mild and easily managed. However, people are all different, and some people may have more favorable results with one medication than another. Zoloft has a slightly different side effect profile that may make it more appropriate for some people than other antidepressants.

There is no way of knowing in advance which psychiatric medication will be most effective for a given person. Unfortunately, a certain amount of trial and error is involved in finding the right medication and the right dose. It is important for a person to be in close communication with his/her doctor when taking Zoloft or any other psychiatric medication, and to discuss symptoms and side effects openly and honestly.

What is the usual dose?

A standard dose of Zoloft is 50 to 200 mg per day. It is taken once a day, either in the morning or evening, and may be taken with or without food.

How long until it starts working?

Although some symptoms may improve within a matter of days, it is important to allow four to six or even eight weeks for the medication to be fully effective. If no improvement is seen in two to four weeks, another medication can be tried.

What are the side effects?

The most common side effects of Zoloft include nausea, diarrhea or loose stools, tremor, insomnia, drowsiness, and dry mouth. These are usually mild; only a small number of patients have discontinued treatment because of side effects. Other potential side effects include increased sweating and sexual problems (delayed ejaculation/orgasm). Although older antidepressants often cause weight gain, 1-2 pound weight loss has been noticed in some people. Zoloft does not seem to cause dizziness upon standing up, and has few cardiac effects.

Patients with epilepsy, liver, and kidney dysfunction should use Zoloft with caution.

Women should notify their doctor if they become pregnant, intend to become pregnant, or are breastfeeding an infant. Use of alcohol in depressed persons taking Zoloft is not recommended.

Some professionals suggest reducing or eliminating intake of alcohol, caffeine, and tobacco while taking any psychiatric medication. These substances may interfere with the way the medication is metabolized in the body and may make a higher dose necessary.

Can Zoloft be taken with other medications?

It is very important that Zoloft not be taken in combination with the antidepressants known as MAOIs (monoamine oxidase inhibitors), such as Nardil, Parnate, or Marplan. Such combinations have caused extreme reactions that could be lethal. Therefore, when switching from an MAOI to Zoloft, or from Zoloft to an MAOI, one should allow 14 days between stopping one and starting the other. Since the potential exists for interaction with over-the-counter drugs, they should be used cautiously while taking Zoloft.

How long should one take it?

This should be discussed carefully with the prescribing physician. Although no one wants to take medication longer than necessary, the chance of relapse is reduced when antidepressant medication is continued for several months, perhaps six to twelve, after the end of the depressive episode. Some researchers estimate that 80% of people having one depressive episode will have another, so it is wise to thoroughly discuss with one's doctor the need for ongoing treatment. When Zoloft is used for long term treatment, periodic review is recommended.

Should someone with bipolar disorder (manic depression) take Zoloft?

People with bipolar disorder often need medication during their periods of depression. Caution must be used when prescribing antidepressants for this group, however, as these medications sometimes induce mania. This happened in a very small group (0.4%) of people taking Zoloft during testing. Mood stabilizers such as lithium, tegretol, and depakene taken with an antidepressant may reduce the likelihood and severity of manic episodes. It is recommended that those taking lithium have their lithium levels monitored after beginning treatment with Zoloft, and appropriate adjustments made in the lithium dose if needed.

Reviewed by Elliot S. Gershon, M.D., Chief, Clinical Neurogenetics Branch, Natonal Institute of Mental Health 11/94