Ask the Doctor: Neuropathic Pain Treatments

As with every kind of chronic pain, the most basic premise of treatment is for the physician to look "at the whole person", not just the part that is injured and hurts ("whole person approach"). There is a long line of diverse treatments for neuropathic pain ranging from medications to physical therapies, psychological treatments, injections and surgery. We will start exploring medications first.

There are two types of drugs that can help. Drugs that specifically work on "injured nervous tissues" and drugs that work as general pain killers.

1.The first class of drugs (often called "neuropathic drugs") are NOT regular pain killers and do not work like regular pain killers (eg. "I take the medication when I hurt and the pain will decrease within an hour or so"). For these drugs to work, they must be taken regularly every day, so that heir level in your blood remains steady. All these drugs have several indications, other than neuropathic pain and work on variable aspects of the pain systems within our bodies.

The older class of these drugs falls under the category of "tricyclic antidepressants" or TCAs, such as amitriptyline, nortriptyline, desipramine etc. Please note that I am using only generic names when I refer to drugs (and not company names known as "brand" names). Your doctor or pharmacist will tell you exactly what the commercial name of these drugs is. While they are good old drugs for depression, they have been also found to work in neuropathic pain and additionally help with sleep and mood. In terms of pain mechanisms, TCAs seem to work in several pain pathways within our nervous system that control neurochemicals called norepinephrine and serotonin.

Another class of neuropathic drugs includes drugs that work against epileptic seizures ("antiepileptics or anticonvulsants"). Examples of these drugs are gabapentin, pregabalin (and the oldest of all, carbamazepine). These drugs seem to work by blocking the activity of irritable nerves, the same way they suppress the explosive activity of an epileptic brain.

Other types of drugs with double and triple properties (for example against neuropathic pain, depression, anxiety etc) include duloxetine, while in some cases pills containing local anesthetic (exactly like the one your dentist gives you when he freezes your tooth), such as mexiletine, may work. All of these drugs work in some way or shape by affecting transmission of nerve impulses within the nervous system.

Very few of these drugs are approved formally by Health Canada for use specifically in neuropathic pain conditions, namely pregabalin and duloxetine. However, "off label use" (use of drugs for other than their approved indications) is widespread and nearly "standard practice".

As with all other drugs, your doctor will have to decide what is best for you based on a number of considerations: What is the effectiveness of the drug? What is the "side effect" profile (eg. what kind of side effects does this drug have and how safe is it for you, particularly if you take other drugs as well)? How expensive is the drug? How easy is it for you to take (eg. do you need to take many pills several time per day or just a few)? The doctor should also have a plan. Every such drug should be given on the basis of a "trial" with a lower dose to start, slow upwards increase based on how well it works and what kind of potential side effects it has, a period of stabilization and then re-assessment. Does it really work? And what happens if it does not work at all? How is the drug going to be reduced and stopped? What is the next alternative? What happens if it only works partially? Will you be given a second drug to increase the effect of the first one? These and other questions should be discussed with your doctor.

Money wise, each province has different regulations regarding neuropathic drugs paid by the provincial health care system for those over 65. Most extended health care plans will cover most or all neuropathic drugs of all classes I reported earlier.

Other classes of drugs are regular pain killers you can take over-the-counter, such as aspirin type of drugs (ibuprofen etc) and acetaminophen in different combinations (those found in Tylenol to name one). However, they do not work well for neuropathic pain. Even prescription drugs that are anti-inflammatories are not very good for neuropathic pain. There is a place for strong pain killers (morphine and morphine-like drugs called opioids), which could be quite helpful when combined with neuropathic drugs. However, their administration should be well thought (a subject of thorough discussion between you and your physician) due to several side effects and risks, and certainly they should not be the first ones or the only ones given for neuropathic pain. Remember, the same questions you will be discussing with your doctor for the neuropathic drugs that I cited earlier, should be asked as well when strong pain killers are contemplated.

Remember, drugs can be very valuable for restoration of our health, but they can also have side effects. An informed consumer, who takes responsibility for his /her health and works hand-in-hand with the doctor, makes a better patient.

Angela Mailis Gagnon, MD, MSc, FRCPC(PhysMed)
Director, Comprehensive Pain Program,
Senior Investigator, Krembil Neuroscience Centre
Toronto Western Hospital,
Chair ACTION Ontario www.actionontario.ca
www.drangelamailis.com