Anti-depressants might not be the first drugs to pop into your brain with regards to pain. Ignoring the fact that many people with chronic pain suffer from some anxiety &/or depression, research has shown that many anti-depressants have direct analgesic (pain relieving) properties! With regards to pain, there are three classes of anti-depressant that are commonly used.
Tricyclic Antidepressants (TCA's)
Selective Serotonin Reuptake Inhibitors (SSRI's)
Serotonin-Norepinephrine Reuptake Inhibitors (SNRI's)
Tricyclic Antidepressants (TCA's)
This class of medication has been used for many many years with regards to pain. They are approved to treat headaches, fibromyalgia, sleep disorders and many other 'off-label' uses. Tricyclic antidepressants are commonly used to treat neuropathic pain.
Common sources of neuropathic pain include diabetic neuropathy and herpes zoster (shingles) infections. They believe that TCA's may have an effect on the serotonin and dopamine levels in the spinal cord, but they do not know exactly how they work for pain.
One bonus is the doses required for pain relief are much lower than that for depression. However, no medication comes without its risks. TCA's commonly slow the heart rate due to something called an 'anticholinergic' effect. If combined with other medications that lengthen the QT interval of our heartbeat, they can stop the heart. Many seniors are on this type of medication, and therefore TCA's are avoided. Unfortunately this is not the only side effect. These include; weight gain, orthostatic hypotension (drop in blood pressure when you change positions), and can be lethal if overdosed. Examples of TCA's include: amitryptiline, nortryptiline, and doxepin.
Selective Serotonin Reuptake Inhibitors (SSRI's)
As their name suggests, SSRI's prevent the reuptake of serotonin in the nervous system. The research suggests that any effect on pain is minimal, however they may be useful in cases of neuropathic pain with accompanying depression. For this, the medications citalopram and paroxetine seem to be the most effective. Again, no medication comes without risks &/or side effects. The SNRI's have been known to cause weight gain, sexual dysfunction, and can have uncomfortable effects if discontinued suddenly.
Serotonin-Norepinephrine Reuptake Inhibitors (SNRI's)
This class of medication includes duloxetine (left), and venlaflaxine. The pain relieving qualities of these medications have helped researchers understand that pain is not caused by one single factor - rather a balance between the neurotransmitters serotonin, norepinephrine, other neurotransmitters, and their receptors.
These medications produce inhibition of the descending pain pathways in the body, while simultaneously having effects on the central pain processing system. Common side effects of the SNRI's include dry mouth, nausea, fatigue, insomnia, constipation, and sexual dysfunction.
Many naturopathic modalities have the bonus of acting on both the pain pathways, and being mood stabilizers. For example, the plant Rhodiola rosea. Studies have shown rhodiola to have a large anti-inflammatory effect, while also helping improve many symptoms of depression (eg: fatigue).
This is only one example of a tool in the naturopathic tool box!
This post is intended for educational purposes only and should not be substituted for medical advice.