For the past several years, TriCyclic AntiDepressants (TCAs) have been used successfully to manage and control a variety of Chronic Pain conditions. Diabetic Neuropathy, post herpetic Neuralgia, and Chronic MusculoSkeletal Disorders are just a few examples.
TCAs have met with some success in treating Chronic OroFacial Pain that may be due to Neurogenic or MusculoSkeletal Dysfunction.
The most frequently used TCAs include the Tertiary Amines, Amitriptyline and Doxepin, as well as the secondary amines, Nortriptyline and Desipramine. TCAs exert at least some of their effects by blocking the re-uptake of the NeuroTransmitters Serotonin and NorEpinephrine.
TCAs are indicated for Chronic OroFacial Pain of Neurogenic or MyoFascial origin when other treatments have failed and Pain remains the chief complaint. These Pains are described variously as deep, dull, and aching (MyoFascial) or as electrical, burning, shooting, stabbing, or lancinating (Neurogenic).
Examples include Fibromyalgia, Trigeminal Neuralgia, and Facial and Tooth Pain that occurs after an invasive procedure or tooth extraction.
TCAs are not particularly helpful in inflammatory pain syndromes, and they should not be initiated if the primary finding indicates joint, bone, or inflammatory muscle involvement. However, in painful conditions of mixed Etiology where inflammation is but one finding, TCAs may be useful as adjunctive therapy.
When comparing TCAs for Pain Control vs. Depression, they are usually given at a lower dose for Pain management. Their onset of action may require less time for controlling Pain than for controlling symptoms of Depression.
The duration of therapy with TCAs is variable. Treatment periods as short as a few weeks and as long as several years have been used to manage Chronic or Intractable Pain Syndromes.
Therapy duration should be determined by clinical observation of patient response as
well as patient tolerance. The side effects of TCAs are related to their ability to effect other Receptor Systems, including the Adrenergic, Cholinergic, Histaminergic, and Dopaminergic.
Patients taking TCAs should be monitored for two reasons: 1) to determine patient compliance with the regimen, and 2) to avoid SupraTherapeutic dosing. TCAs are not habit forming, and there have been only a few reported cases of organ toxicity with long term use.
TCAs can be a valuable addition to the therapeutic armamentarium, particularly in Neuropathic Pain syndromes. They should be initiated at a low dosage and gradually titrated upward until adequate Pain relief is achieved or until side effects limit dosing.
In addition to reducing Pain severity, they can decrease other symptomatic complaints that often accompany Chronic Pain, including Depression and sleep disturbance.
Dentists and physicians should have a firm understanding of the increasing use of TCAs for managing both Pain and Depression, even if they are not comfortable prescribing these medications.
