Back Pain Medications and Injections

Back Pain Medications and Injections
By Brennan Howe
Among the common pain relief medications prescribed by physicians are muscle relaxants, antidepressants, NSAIDs (nonsteroidal inflammatory drugs) and COX –2 inhibitors.  Some popular muscle relaxants are cyclobenzaprine (Flexeril), carisoprodol (Soma), methocarbamol (Robaxin) and gabapentin, in seizure medications.  The NSAIDs help with stiffness and in reducing inflammation.  Opiates like Duragesic or OxyContin may be prescribed but are not a popular choice with a low risk of possible addiction.
 
With all medications, other treatment strategies should be combined into the relief program.  So physical therapy, movement and posture techniques and other treatment options should be carefully assessed to see which combination best helps relief over time.

Doctors may also prescribe injections, such as Sacroiliac joint blocks, Thoracic Facet Joint injections, Epidural steroid injections, selective nerve root block, and Facet rhizotomy.

Muscle relaxants act on the brain, not on the muscle.  They help relieve pain so that patients are able to exercise and have other physical treatments that would otherwise be too painful.  Muscle relaxants are sedatives, so doctors may prescribe them to be taken at night to avoid daytime drowsiness.  They should not be taken when driving or operating heavy machinery.  Muscle relaxants have been shown to be effective alone or in conjunction with anti-inflammatory medications within a week of the onset of severe muscle spasm in the lower back.  Side effects include drowsiness, dizziness, addiction after one week of use, dry mouth and urinary retention.  Some common muscle relaxants are carisoprodol (Soma), cyclobenzaprine (Flexeril), diazepam (Valium), metaxalone (Skelaxin), methocarbamol (Robaxin).

Low doses of tricyclic antidepressants have been used to relieve chronic back pain.  They work by increasing the level of certain chemicals in the brain that change the way the brain perceives pain.  They are not used for sudden and acute pain, and usually take two to three weeks to go into effect.  Side effects include constipation, dry mouth, blurred vision, drowsiness, fatigue, low blood pressure, weight gain, increased appetite, sweating, and urinary retention.  Since side effects vary from medication to medication, it is worth trying another antidepressant if one does not work well.  Some common antidepressants used to treat are amitriptyline (Amitril, Elavil, Endep), doxepin hydrochloride (Sinequan), imipramine hydrochloride (Janimine, Tofranil), nortriptyline (Pamelor), and desipramine (Norpramin).

NSAIDS and COX-2 inhibitors are effective in relieving pain and reducing inflammation.  They are generally the first line of treatment in acute low back pain.  NSAIDS are usually taken for one to three weeks but can be taken for four weeks or longer.  People under the age of twenty should not take NSAIDS because they can cause Reye’s syndrome, a central nervous system disorder.  Other people who should not take NSAIDS include those taking blood thinners, corticosteroids, lithium, and oral antidiabetic medication.  Before taking NSAIDS you should let your doctor know if you are pregnant, trying to get pregnant, breastfeeding, or have a peptic ulcer, history of gastrointestinal bleeding, nasal polyps, kidney or liver disease, allergic reactions to aspirin or related drugs, anemia, or a blood-clotting defect.  Short-term side effects can include stomach irritation, which can be minimized by taking them with food and a full glass of water.  Taking NSAIDS long term can cause ulcers.  In rare cases, naproxen, ibuprofin and rofecoxib have caused meningitis.  A common nonprescription NSAID is aspirin (Anacin, Bayer, Bufferin).  A common prescription NSAID is naproxin (Naprosyn).  Some common COX-2 inhibitors are celecoxib (Celebrex), rofecoxib (Vioxx), and valdecoxib (Bextra).

COX-2 inhibitors are less likely to cause stomach problems,

but they may increase the risk of heart attack.  If you have a history of heart trouble, talk to your doctor to see if COX-2 inhibitors are best to treat your back pain.

Injections
Spinal injections have been used to as an alternative to surgery in treating since the early 1900s.  Studies have shown injections to be effective in up to 50% of patients.  They are typically given after medication and physical treatments have been utilized, but before surgery.  Injections tend to be more effective than oral pain medication because they deliver medicine right to the source of the pain.

Sacroiliac (SI) joint blocks are injections used to treat low back pain.  The sacroiliac joints are located next to the spine and connect the sacrum to the pelvis. Painful joints cause pain in the lower back, buttocks, abdomen, groin, and legs.  SI joint blocks work in three ways: 1) they are used to determine if the SI joint is the source of (if the injection makes the pain better, that’s where the pain is coming from), 2) the numbing medication used in the block gives temporary relief so the patient can have chiropractic or other physical treatments immediately after the block is administered, and 3) a time-release steroid gives extended pain relief by reducing inflammation.
During an SI block, the patient lies on his stomach and live x-ray, known as fluoroscopic guidance, is used to allow the doctor to see the joints.  The skin is sterilized and numbed.  The doctor then inserts a very small needle into the joint and injects it with lidocaine (a numbing agent) and a steroid (an anti-inflammatory).  After treatment the legs sometimes feel numb or weak for a few hours.  Side effects are rare and include allergic reaction, infection, excessive bleeding, nerve damage, and chemical meningitis.
 
Thoracic Facet joints are small joints about the size of a thumbnail and are located in pairs along the back of the spine.  If they become irritated, middle occurs.  Thoracic facet joint injections have the same purpose as SI joint injections, are performed in exactly the same manner, and have the same side effects.  The only difference is they treat middle instead of lower back pain.

Epidural steroidal injections are similar to SI and thoracic facet join injections, except the cortosteroid is injected into the spinal canal surrounding the spinal cord.  They are used to treat chronic and not acute low back pain.  This procedure has the same side effects of other injections.  Relief generally lasts anywhere from one week to one year.

Selective nerve root blocks (SNRB) are used primarily as a diagnostic tool and secondarily as treatment for pain.  Back pain can occur when nerve roots become compressed and inflamed.  While MRIs can be used to show which nerves are causing the pain, they don’t always work successfully.  In cases when this happens, an SNRB injection can be performed in order to isolate the source of the pain.  SNRBs are also used to treat disc that rupture outside of the spinal canal, or far lateral herniated discs.  The procedure is the same for other types of injections.  As with other injections, SNRBs should not be performed more than three times per year.  SNRBs are considered more difficult to perform than other types of injections and should be done only by a physician experienced in them.

Facet rhizotomy may be recommended if three facet blocks have been performed but more pain relief is needed.  Facet rhizotomy injections disable the sensory nerves that lead to the facet joint, thereby providing pain relief.  The procedure for facet rhizotomy injections is different from that of other injections.  A needle with a probe is inserted just outside the joint, is heated with radio waves, and applied to the sensory nerve.  This disables the nerve and keeps it from sending pain signals to the brain.