What Is a Tricyclic Antidepressant?

Tricyclic antidepressants, or TCAs, have been in use for years to treat behavioral health disorders. Recently, they have been found to be effective for other health problems also. Amitriptyline (brand name Elavil), desipramine (brand name Norpramin), nortriptyline (brand name Pamelor), doxepin (brand name Sinequan), imipramine (brand name Tofranil), protriptyline (brand name Vivactil) and trimipramine (brand name Surmontil) are common tricyclic antidepressants.

Depression and Anxiety

Tricyclic antidepressants are most often prescribed for depression and anxiety. They can often work when selective serotonin reuptake inhibitors (SSRIs), now the first-line treatment for these disorders, fail. Three neurotransmitters in the brain, serotonin, norepinephrine and dopamine, control anxiety and state of mind. TCAs work to keep more of these neurotransmitters available, which improves mood.

Pain Control

TCAs are also useful for patients with chronic pain conditions but who aren't necessarily experiencing depression or anxiety. Doctors aren't sure why tricyclic antidepressants work for pain control, but they theorize they may increase the neurotransmitters in the spinal cord that act on pain signals. TCAs work best for pain from diabetes, shingles, tension and migraine headaches, low back pain and fibromyalgia. Unlike medications strictly for pain control, TCAs take a few weeks to start working.

TCAs and TMJ

Some of the TCAs are also effective for tempromandibular joint disorder, or TMJ, a common condition where the jaw joint does not work properly. TMJ can cause significant pain, not only in the jaw, but in the shoulders, neck and head. TCAs can help in a variety of ways. Because they have a sedating effect, they can help the TMJ patient sleep better. They also reduce bruxism, or teeth grinding, a problem many TMJ sufferers experience. In addition, they can give some pain relief. Because TMJ is a chronic condition, many patients also suffer from depression, and the TCA has the added benefit of helping with that.

Side Effects

Although they are not addictive, TCAs have a number of side effects that can be intrusive on a patient's daily life. Side effects include drowsiness, dry mouth, dizziness, headache, nausea, weight gain and blurred vision. Since all the TCAs are effective, doctors tend to choose one based on other problems a person has and other drugs he may be taking. Some of the TCAs, especially amitriptyline, can cause marked drowsiness, so they are often prescribed for patients who are experiencing anxiety and depression with agitation. The TCAs that rarely make people sleepy, such as imipramine, are usually given to depressed patients who are lethargic and withdrawn.

Drug Interaction

Patients who are already taking antihistamines, other allergy medications, tranquilizers, pain medication seizure medication or muscle relaxers should talk to their doctor before combining them with TCAs. They should also avoid combining TCAs with alcohol or any substance that makes them sleepy.