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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, Celebrex, and Bextra. 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, Norflex, 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 Tegretol. 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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