- Neuropathic low back pain and neck pain
affect about 7-8% of the world's adult population.
- It is a leading cause of
occupational disability and results in a significant economic burden.
- Neuropathic pain does
not respond to conventional analgesics and anti-inflammatory drugs.
- Pharmacological agents
like tricyclic antidepressants, gabapentin, pregabalin and
serotonin-norepinephrine reuptake inhibitors (SNRIs) have been found the most
beneficial in pain management.
Neuropathic pain in the neck
and lower back affects
around 7-8% of the adult
population and leads to loss
of a significant
number of workdays. It does not respond to common analgesics and
anti-inflammatory drugs. A recent article in the US Pharmacist
reviewed the treatment options available and provided
chronic pain caused due to damage to the nervous system. It may be accompanied by damage to the nerve fibers as well.
Neuropathic pain may be associated with tingling, numbness
or a burning sensation
which spreads along the route of the nerve. While neuropathic pain is described
as a 'sharp, stabbing' pain, musculoskeletal pain is 'dull and aching' in
‘Pharmacological therapy with gabapentin, pregabalin and serotonin-norepinephrine reuptake inhibitors helps in neuropathic pain management.’
As mentioned earlier, common analgesics
do not provide relief in
case of neuropathic pain. Practice guidelines issued by American College of
Physicians and American Pain Society indicate evidence in support of
non-pharmacological treatments for chronic
back pain such as yoga
and physical therapy but little evidence exists to prove
in neuropathic pain.
The preferable and most accepted treatment
regimen or first line of treatment of neuropathic pain is as follows:
Line of Treatment
- Tricyclic Antidepressants (TCA) like amitriptyline, desipramine and nortriptyline relieve neuropathic pain
in both normal as well as depressed individuals. TCAs are beneficial in
pain-related insomnia (lack of sleep) too. They are well tolerated and
therefore are the first choice of treatment.
Associated side effects of TCAs may be
drowsiness, dizziness, dry mouth and general weakness.
- Anticonvulsants / Gaba Analogs:
Gabapentin and pregabalin are anticonvulsants
which have been found efficacious in the management of various neuropathic pain
syndromes and can be used as the first choice of treatment in patients in whom
TCAs are contraindicated.
side-effects that may occur with their use are constipation, dry mouth, nausea,
headache, and loss of balance.
reuptake inhibitors (SNRIs)
Duloxetine and venlafaxine are SNRIs which provide
relief in nerve-related pain and are also useful in treating concomitant depression.
Drowsiness, dizziness, dry mouth, and nausea are some of the
side-effects that may be observed with their use.
When the first line of treatment does not work
or its use is limited due to side-effects, the second line of treatment is used in the
form of tramadol
. Several trials have
shown that tramadol
provides effective symptomatic relief in neuropathic pain.
Other options include topical agents like capsaicin and lidocaine patches
. Lidocaine patch(5%)
can be used for pain relief in patients who are unable to tolerate oral drugs
due to side-effects. Lidocaine acts as a local anesthetic agent and provides
short-term relief from pain.
(8%) can be used topically but may result in a rise in blood pressure. It may also cause
burning and irritation at the site of application unless ice is applied.
like morphine are given the least
preference in the treatment of neuropathic pain and remain as third line
therapy and can provide
further relief when used in conjunction with gabapentin. Their
propensity to cause dependence is a major deterrent to their use.
The property of botulinum toxin A
to inhibit both the secretion of
inflammatory mediators and the
release of neurotransmitters from nerve fibers is utilized for pain
relief through subcutaneous injections of the toxin.
The general rule to be applied in the clinical
management of neuropathic pain is the use of a single drug at a time. The transition
from starting dose to target dose must be titrated and patient safety must be
kept in mind. In case a drug does not produce desired effects, a combination of
two may be tried. It is important to keep the patient's medical history, age, and comorbidities
in consideration while deciding on the line of treatment.
Certain other agents are also being researched
for the management
of neuropathic pain. One of these involves mutation of SCN9A, which blocks the pain signals that are carried
by the nerve cells. The loss of pain sensation is mainly due to the blockage of
voltage gated sodium channels (NaV)1.7 Studies are also under way to
research an agent which is associated with nitric oxide production in
neuropathic pain. Inhibition of nitric oxide production may result in pain
Owing to the various factors and complexities
involved in the management
of neuropathic pain, it may be advisable to use a multidisciplinary approach
involving the use
of pharmacological therapy as well as alternative treatments like
physiotherapy, rehabilitation, support groups and behavioral therapy.
Pharmacological therapy would still remain the mainstay of treatment. However,
informed decisions regarding treatment must be made according to the patient's
characteristics and comorbidities.