Use of Antidepressants in the Treatment of Chronic Pain

By Adler Giersch ps

Originally developed and approved to treat depression, antidepressant medication has been found effective for treatment of chronic pain. Preferring to blame and discredit the victim of traumatic injury, many insurance companies attempt to argue that prescription of antidepressants is proof that the patient’s symptoms are “all in their head” and not related to physiological injury. Many patients feel stigmatized by the label “antidepressant”, understanding the perceptions held by those outside the treatment arena. This perspective is founded in a misunderstanding of the neurophysiology of pain and ignorance of the medical literature on the subject.

Active treatment modalities are important for improved function and repair of traumatic injuries. Use of medications such as nonsteroidal antiinflammatories (NSAIDs), muscle relaxants and pain medication may be appropriate, but each has its own benefits and risks. Some (but not all) antidepressants have been found to be effective in treatment of pain, fatigue, sleep disturbance and health-related quality of life.1 These generally work without the risk of the gastrointestinal effects of NSAIDs or the risk of addiction of some pain medications, such as opioids. Side-effects of antidepressants, particularly the newer classes, are generally mild.

Antidepressants are believed to be effective for the treatment of chronic pain for a number of reasons:

The neurotransmitters associated with depression, serotonin and norepinephrine, are the same as those associated with pain. Increased levels of these neurotransmitters at nerve endings is believed to strengthen the system that inhibits pain signal transmission.

Chronic pain frequently leads to sleep disturbance. Certain antidepressants, such as amitriptyline, have a sedating effect, improving sleep. Improved sleep is often associated with increased tolerance to pain and is necessary for rehabilitation efforts to be maximized.

Patients with chronic pain often develop depression as a result of the pain and daily limitations as a result of injury. Breaking the pain-depression cycle may, again, improve tolerance to pain.

Despite the commonality of the neurotransmitter connection, depression and chronic pain respond differently to different types of antidepressant medication. These drugs are as effective for non-depressed patients as those who are depressed. Improvement in pain did not correlate with depression response in a review of studies which evaluated that connection.2

There are several classes of antidepressants available. Tricyclic antidepressants (TCAs) have been used in the treatment of both depression and pain for many years. This class includes amitriptyline (Elavil), desiprimine (Norpramin), and nortriptyline (Pamelor), among others. Amitriptyline is the most commonly used and most widely studied of this class. It is considered to be very effective for treatment of pain, however, it has a higher incidence of side effects than newer drugs.

Selective serotonin reuptake inhibitors (SSRIs), such as fluoxetine (Prozac), paroxetine (Paxil), citalopram (Celexa) and escitalopram (Lexapro), have fewer side-effects and are less sedating than the TCAs. These have been found effective primarily for headache prevention but inconclusive or disappointing in the treatment of neuropathic pain.

Selective serotonin and norepinephine reuptake inhibitors (SNRIs) generally have the fewest side-effects and are now the most commonly prescribed antidepressants for pain management. This class includes duloxetine (Cymbalta), venlafaxine (Effexor) and buproprion (Wellbutrin and Zyban). Venlafaxine has been shown to be effective in the treatment of neuropathic pain, such as diabetic neuropathy.3

Understanding how antidepressant medication and the general guidelines for its use can help the health care provider educate the patient on these medications and alleviate the stigma often attached to their use.

If your patient has suffered a traumatic injury due to the fault of another and has reached the stage of being prescribed antidepressants for chronic pain, any insurance company involved may attempt to use the stigma of the term”antidepressant” to discredit the patient and his or her experience of pain. Making a note in the patient’s chart on the reason and purpose of the prescription would go a long way in the rebutting an insurer’s response that the patient does not have real physical pain but only “in their head.” Also, the patient should consult with counsel experienced in the whole array of medical treatments and insurance company arguments to protect his or her legal rights and understand the real use of this treatment option.

1 Hauser W, Bernardy K, et al., Treatment of fibromyalgia syndrome with antidepressants: a meta-analysis. JAMA. 2009 Jan 14;301(2):198-209.
2 O’Malley PG, Jackson JL, et al, Antidepressant therapy for unexplained symptoms and symptom syndromes. J Fam Prac 1999 Dec; 48(12):980-90
3 Sarto T, Wiffen PJ Antidepressants for neuropathic pain. Cochrane Database Syst Rev, 2007 Oct 17;(4):CD005454.