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Medications
for chronic back pain
Medications are frequently prescribed for back pain. Again, it is important
to remember that there is no one best medicine for back pain, despite what
your friends and relatives tell you. Rational use of medication depends on a
diagnosis of the cause of the pain. Medications for nerve irritation will not
work for joint pain, and vice versa. The most common medications used
for back pain include anti-infammatory medications,
muscle relaxants, medications for pain coming from injured nerves
(anticonvulsants, antidepressants, and others), and analgesics (non-specific
pain medications). The choice of a medication is based on which group is most
appropriate for a given diagnosis, and which member of the group is most
appropriate for the individual. Often the process involves trials of different
medications to judge the patient's therapeutic response and tolerance.
Anti-inflammatory
medications
Nonsteroidal anti-inflammatory drugs (NSAIDS) are
probably the most commonly prescribed medications for back pain. They reduce
inflammation in the body by interfering with the production of a group of
chemicals called prostaglandins. The rationale is based upon the concept that
much of the pain experienced is due to inflammatory processes which have run
amok and are no longer serving any useful purpose. In addition to the
anti-inflammatory action of these drugs, they all have a non-specific
analgesic effect similar to acetaminophen, (Tylenol). They all have similar
side effects related to the fact that some of the prostaglandins in the body
serve a useful function, like protecting the stomach from acid and regulating
blood flow in the kidney. Thus, common side effects include stomach
irritation (including gastritis and ulcers), impaired kidney function and
high blood pressure. Common NSAIDS in clinical use include Motrin, Relafen, Naprosyn, Clinoril, and others.
Newer NSAIDS are more COX2 selective, reducing side effects due to inhibition
of the "good" prostaglandins. These include Mobic
and Celebrex. There is recent evidence, however, that these COX2 selective
agents may increase the risk of heart disease and stroke.
Muscle
relaxants
Back pain frequently has at least a component of muscle tension or spasm
contributing to the symptoms. A cycle develops with muscle tension causing
pain which causes more muscle tension. The various medications used for
increased muscle tension work at different points in the cycle. Most have
drowsiness as the limiting side-effect. Common muscle relaxants include Flexeril, Zanaflex, Robaxin,
Soma, and Baclofen.
Medications
for pain coming from injured nerves
Pain can be caused by injury to the nerve fibers in the spinal nerve roots.
The mechanism of pain production is complicated, with secondary changes
taking place in the spinal cord and brain. Much of the pain seems to be due
to spontaneous firing of the injured nerves, with the brain interpreting this
firing as pain. There are two main classes of medications used to reduce this
firing: the antidepressants and the anticonvulsants. The antidepressants used
are the older tricyclic antidepressants such as Elavil and Pamelor. These have
an effect on the nerve fibers themselves. When they are effective, they are
effective at doses well below the antidepressant level. The anticonvulsants
probably work on the nerves themselves as well as having central actions. The
most common ones used are Neurontin and Lyrica. In both categories there are
numerous other medications with slightly different side effect profiles which
can be used if the primary ones are not tolerated or are not fully effective.
In addition to these two major groups there are some others which can be
effective for some people. Mexital (an oral form of
the anesthetic lidocaine) is one member of this
miscellaneous group, as are topical preparations like capsaicin creams and
topical Lidoderm patches.
Analgesics
These are medications which reduce pain in a non-specific fashion. All of the
NSAIDS can be used for this purpose, as well as Tylenol. If these are not
strong enough then the next level usually involves medications like Ultram. This is a non-narcotic pain medication, but some
people find it hard to stop after regular use without experiencing a
withdrawal syndrome. Other medications at this same level include Tylenol
with codeine, and Vicodin (Tylenol with hydrocodone).
More severe pain may require the use of opioid analgesics. Usually a
long-acting agent is taken on a regular basis, and a short-acting agent is
used for breakthrough pain. These are narcotics and require careful
supervision. They can be very effective and safe if used properly. People
using opioids on a regular basis develop
habituation (they must taper slowly or experience withdrawal), but rarely
develop addiction (drug-seeking behavior).
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