Health Library Atypical Antidepressants for DepressionFrom Healthwise

These medications are antidepressant medications that do not fit well into any of the other medication categories. They are taken in tablet form (orally).

Bupropion, duloxetine, mirtazapine, trazodone, and venlafaxine balance certain brain chemicals (neurotransmitters). When these brain chemicals are balanced, the symptoms of depression are relieved.

These medications may be tried when other antidepressants are not effective or have problematic side effects. They may be used on their own or along with another drug.

Sometimes certain selective serotonin reuptake inhibitors (SSRIs) or other antidepressants can cause significant problems with sexual function. Bupropion is less likely to cause sexual dysfunction than other antidepressants, such as SSRIs. When sexual dysfunction side effects occur, bupropion may be prescribed instead of, or in addition to, an SSRI.

Mirtazapine may be useful if you are experiencing insomnia or agitation.

Trazodone is often used along with an SSRI to help with sleep disturbances.

When these drugs are not used

You should not take one of these medicines if you have had an allergic reaction to it in the past or if you have taken a monoamine oxidase inhibitor (MAOI) within the past 2 weeks. If you have taken an MAOI within the past 2 weeks, taking bupropion may cause life-threatening high blood pressure.

You should not take duloxetine if you have uncontrolled narrow-angle glaucoma, liver disease, or abnormal liver function tests.

You should not take bupropion if you have had a seizure or an eating disorder.

You should not take trazodone if you are recovering from a recent heart attack or have carcinoid syndrome.

Although sometimes used in children, these medications have not been approved for use in people under the age of 18.

These antidepressants may be as effective as selective serotonin reuptake inhibitors (SSRIs) in treating depression. Bupropion, duloxetine, mirtazapine, trazodone, and venlafaxine are all effective in treating adults. Venlafaxine is not effective in treating children or adolescents who have depression. Experts are still studying whether bupropion is an effective medicine for children or adolescents.

Bupropion, duloxetine, mirtazapine, trazodone, and venlafaxine have different side effects than selective serotonin reuptake inhibitors (SSRIs), cyclic antidepressants, or monoamine oxidase inhibitors (MAOIs).

Trazodone has numerous side effects, and in rare cases, some can be severe.

The most common side effects of each of these medications are listed below.

Duloxetine possible side effects

• Nausea
• Dry mouth
• Constipation
• Decreased appetite
• Fatigue
• Sleepiness
• Increased sweating
• Sexual dysfunction

Other more serious side effects are rare but can include liver problems (particularly in patients who drink a lot of alcohol), increased blood pressure, activation of mania or hypomania, seizures, and mydriasis (pupil dilation), which can cause problems for people with narrow-angle glaucoma.

Side effects when discontinuing duloxetine can include dizziness, nausea, headache, paresthesia (abnormal touch sensation or tingling), vomiting, irritability, and nightmares.

Bupropion possible side effects

• Weight loss of more than 5 lb (2.3 kg)
• Agitation, confusion, nervousness, and anxiety

In rare cases, bupropion can cause other adverse effects, some of them serious, such as allergic reactions, dry mouth, headaches, heart palpitations, and seizures.

Mirtazapine possible side effects

• Drowsiness
• Increased appetite or weight gain
• Increased cholesterol levels
• Dizziness
• Dry mouth
• Constipation

Other more serious side effects are rare but can include agranulocytosis (insufficient white blood cell count), allergic reactions, and liver or pancreas problems.

Venlafaxine possible side effects

• Constipation
• Headaches
• Weight loss
• Dry mouth
• Slight increase in cholesterol
• Hypertension
• Sexual dysfunction

Side effects when discontinuing venlafaxine can include dizziness, nausea, headache, abnormal touch sensation or tingling (paresthesia), vomiting, irritability, and nightmares.

Trazodone possible side effects

• Drowsiness
• Dizziness or lightheadedness
• Blurred vision
• Weight gain
• Dry mouth
• Constipation
• Headache
• Nausea

Side effects may also include priapism, a painful condition in which the penis stays erect. If this happens, call your doctor at once.

FDA Advisories.

• The U.S. Food and Drug Administration (FDA) has issued an advisory on antidepressant medicines and the risk of suicide. The FDA does not recommend that people stop using these medicines. Instead, a person taking antidepressants should be watched for warning signs of suicide. This is especially important at the beginning of treatment or when the doses are changed.
• The FDA recommends patients at risk for glaucoma be watched for signs of pupil dilation (mydriasis) when taking venlafaxine.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

Bupropion may trigger seizures in some people. You will probably want to avoid taking this medication if you have a history of seizures or eating disorders.

You may start to feel better within 1 to 3 weeks of taking antidepressant medicine. But it can take as many as 6 to 8 weeks to see more improvement. If you have questions or concerns about your medicines, or if you do not notice any improvement by 3 weeks, talk to your doctor.

These medications should not be used along with monoamine oxidase inhibitors (MAOIs) because serious, sometimes fatal, reactions can occur. To avoid serious reactions, wait at least 14 days after ending an MAOI treatment before beginning treatment with any one of these medications.

Complete the new medication information form (PDF)(What is a PDF document?) to help you understand this medication.

Author:	Jeannette Curtis Ralph Poore	Last Updated: March 21, 2007
Medical Review:	Martin Gabica, MD - Family Medicine Lisa S. Weinstock, MD - Psychiatry
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