Medications

A better understanding of the wide variety of medication choices that are utilized for pain management begins with an understanding of some neurological pain pathways. When a structure such as your spine or knee are injured, the signals are carried into the spinal cord through sensory nerves that connect to a second pain nerve cell, which then carries the signal to the brain. The injury causes inflammation which in turn causes certain reactive neuroinflammation changes in the nerve at the injury site, within the spinal cord, and in the brain. There are also pathways in the brain and deeper structures of the brain and spinal cord that fight or inhibit pain. The brain can send signals down to the spinal cord and quiet the pain signaling, thus lessening your pain. The brain responds to and sends these pain inhibiting signals using a complex variety of chemicals. The medications used for pain management include both those that decrease the incoming pain signaling and those that enhance the brain’s downward signaling to the spinal cord to dampen or reduce the effect of the pain signaling. Some medications have both effects by having more than one action on the nervous system and body.

Injury to the spine or other areas of the body sparks inflammation at the injury site and also starts an inflammatory chain reaction. This causes hypersensitivity of the nerve endings at the injury site, and those nerves then also promote more inflammation early on after the injury. These signals also spark changes in certain cells within the spinal cord and brain (microglia and astrocytes) that enhance inflammation within these central nervous system areas. These changes, known as neuroinflammation, increase the sensitivity to pain. This is normally a temporary increase in pain sensitivity, but when this doesn’t quiet down normally, can lead to chronic pain.

Classifications

For the purposes of classifying which medication or medications your medical provider may suggest, pain can be thought of as acute, or pain that is due to a new injury and present for less than 6 weeks, and chronic, or pain that has been present for a long time, generally 3 months or more.

One important class of medications that are utilized both early after an injury and sometimes with chronic pain are the anti-inflammatory medications. These can be divided into two classes:

• Steroids (corticosteroids) – For pain management, the corticosteroid medications such as prednisone, methylprednisolone, or dexamethasone, are generally used for days at a time, and not on a frequent basis.
• Non-steroidal anti-inflammatory drugs (NSAIDs) – Anti-inflammatories can be used for days, a few weeks, or longer, with careful watch for any side effects. Some commonly used options from these drug classes include ibuprofen, naproxen, etodolac, meloxicam, diclofenac, nabumetone, indomethacin, and ketorolac.

These drugs are often used in the early stages following injury, on an as needed basis for chronic pain, and much less frequently on a long-term basis. Drugs within both classes have risks to the stomach, kidneys and liver, and these risks increase the higher the dose and the longer you use them.

Pain Relievers (Analgesics)

Along with the NSAIDs above, acetaminophen (Tylenol), Tramadol, and opiates are most used. Acetaminophen has a complex action, including stimulation of cannabinoid receptors in the brain and brain stem. It can be helpful alone, or in combination with anti-inflammatory drugs or other medications. It may have a central brain anti-inflammatory effect, as well.

Atypical Opioids

There are opioids that have combination effects, including stimulation of the opioid receptors in the brain, as well as some of the same chemicals (neurotransmitters) that are affected by antidepressant medications. Tramadol and Tapentadol (Nucynta) are examples of these that we prescribe. These medications provide some opioid effect, boosted by other chemical effects on the brain, and are somewhat safer with less potential for misuse. Buprenorphine has emerged as a very important pain reliever, which also stimulates the opioid receptors in the brain and brain stem, but with less potential for overdose. This comes in patch and oral dissolving film and pill forms. These atypical opioids are often better choices for pain management than traditional opioids.

Muscle Relaxants

Muscle relaxants generally have complex actions on the brain and spinal cord, helping to reduce muscle tension and pain. These may have a sedating effect and are occasionally used both for promotion of sleep and pain relief. Commonly used muscle relaxants include cyclobenzaprine (Flexeril) tizanidine, and methocarbamol. Because of their potential for sedation, they should be used cautiously with opioids, sleeping medications, and should not be mixed with alcohol.

Antidepressant Medications

The antidepressant medications, especially those that increase levels of the neurotransmitter norepinephrine, are very useful for pain management. These can be helpful alone or in combination with other pain medications. Some are also useful for promotion of sleep. Venlafaxine, Duloxetine, as well as Amitryptyline, nortriptyline, and others are helpful for pain management, as well as promote sleep. Some antidepressants are excellent for sleep promotion, such as trazodone and low dose doxepin.

Antiseizure Medications

Antiseizure medications quiet pain signaling, thus reducing pain. Some people find that they also have a sedating effect, and can be used at night for sleep, or a calming effect, which can treat anxiety in addition to pain. The most commonly used drugs from this class include gabapentin (Neurontin) and pregabalin (Lyrica).

Topical Medications

Topical medications can be very helpful alone or complementary to other pain medications. These commonly include lidocaine, menthol, diclofenac, or capsaicin. These can be found in over-the-counter preparations.

NMDA-Receptor Antagonists

This is a very complex set of medications which often has significant side effects. They include ketamine, dextromethorphan, memantine, and amantadine. The opioids methadone and levorphanol are also NMDA-receptor antagonists. Your provider at The Denver Spine and Pain Institute can counsel you regarding the pros and cons of these medications.

Migraine Medications

Migraine medications take the form of preventative medications, and those that are used to treat headaches as they arise. Medications used to prevent migraine headaches include betablockers, antiseizure medications, and CGRP inhibitors. There are also medications designed to stop a migraine headache as it starts. There are also certain supplements that may help with headache prevention, including magnesium, riboflavin, coq10, feverfew and omega 3 fatty acids.

Alpha Agonists

Alpha 2 agonist medications such as tizanidine are used for muscle relaxation. Others such as clonidine can be used to stop withdrawal symptoms that may arise due to tapering or stopping of opioid medications. This medication can sometimes be helpful in helping someone ween from opioid use in a comfortable manner.