Tricyclic antidepressants (TCAs)

TCAs are a type of antidepressant that can relieve the symptoms of depression, such as sadness and irritability. Learn how they work and what side effects they can cause.

Certain brain chemicals called neurotransmitters are associated with depression, including the neurotransmitters serotonin (ser-oh-TOE-nin), norepinephrine (nor-ep-ih-NEF-rin) and dopamine (DOE-puh-mene). Research suggests that abnormalities in neurotransmitter activity can affect mood and behavior.

How TCAs work

Tricyclic antidepressants (TCAs) inhibit the reabsorption (reuptake) of serotonin and norepinephrine. To a lesser extent, TCAs also inhibit reabsorption of dopamine. These antidepressants also block certain cell receptors, which accounts for many of their side effects. TCAs are called tricyclic because of their chemical structure. They were among the earliest of antidepressants, hitting the market in the 1960s, and they remained the first line of treatment for depression through the 1980s, before newer antidepressants arrived.

TCAs approved to treat depression

Here are the TCAs that have been approved by the Food and Drug Administration specifically to treat depression, with their generic or chemical names followed by available brand names in parentheses:

Amitriptyline
Amoxapine
Desipramine (Norpramin)
Doxepin (Sinequan)
Imipramine (Tofranil)
Nortriptyline (Pamelor)
Protriptyline (Vivactil)
Trimipramine (Surmontil)

Some of these medications come in forms that must be injected or as oral solutions that must be mixed with liquids, such as water or juice.

Some of these medications may also be used to treat conditions other than depression.

Side effects of TCAs

Because TCAs are less selective about which cells they affect, they typically have more side effects than other antidepressants.

Side effects of TCAs include:

Drowsiness
Dry mouth
Blurred vision
Constipation
Urinary retention
Dizziness
Impaired sexual functioning
Increased heart rate
Disorientation or confusion
Headache
Low blood pressure
Sensitivity to sunlight
Increased appetite
Weight gain
Nausea
Weakness

Safety concerns with TCAs

In general, avoid tricyclic antidepressants if you have narrow-angle glaucoma, an enlarged prostate (benign prostatic hyperplasia) or certain types of heart disease. TCAs are associated with a higher risk of heart attack. TCAs may affect blood sugar levels. If you have diabetes, you may need to check your blood sugar more often. TCAs should be used with caution if you have a history of seizures or thyroid problems.

Stopping treatment with TCAs

TCAs aren't considered addictive. However, stopping treatment abruptly or missing several doses can cause withdrawal-like symptoms, including:

Nausea
Headache
Dizziness
Lethargy
Flu-like symptoms

This is sometimes called discontinuation syndrome. Talk to your doctor before stopping so that you can gradually taper off the medication.

Suicidal feelings and TCAs

In some cases, antidepressants may be associated with worsening symptoms of depression or suicidal thoughts or behavior, particularly early in treatment or when you change your dosage. Be sure to talk to your doctor about any changes in your symptoms. You may need more careful monitoring at the beginning of treatment or upon a change in treatment, or you may need to stop the medication if your symptoms worsen.