Painful diabetic peripheral neuropathy
By Nina Nazor
Painful neuropathy can be one
of the most distressing and debilitating of all the complications of diabetes. Usually the pain is most pronounced in the
lower limbs, although, in more severe cases, the fingers and hands may also be involved. Some people experience pain in all
their body, which increases at night. The pain can be so bad that the person might not even be able to stand the touch of
silk on the skin.
What are the symptoms of painful diabetic peripheral
Some of the most common are the following:
· Allodynia (pain from the touch of clothing)
Management of painful neuropathy
The first step must be to exclude other causes, particularly malignant disease and toxic causes (cancer, alcohol
abuse or HIV.)
Sometimes a visit to a neurologist who can measure the damage
to the nerves by a method called electromiography might be desirable, although this would simply confirm the presence of neuropathy
but does not indicate the underlying cause.
After diagnosis, the health
care team must provide you with a full explanation of the condition, allaying your fears and misconceptions, and informing
you that the pain may resolve in time can be extremely reassuring.
tips, such as the use of a bed cradle to lift the bedclothes off of the skin, can be really helpful. Advice on proper footwear
is very important too. In persons with relatively mild pain, simple analgesics or anti-inflammatory medications may be enough
to treat the discomfort.
Metabolic control and painful neuropathy
Some evidence suggests that stable glycemic control is very important.
A recent study using continuous glucose monitoring associated painful symptoms with erratic blood glucose levels.
Medications to treat painful neuropathy
Nonsteroidal and anti-inflammatory drugs are used for the management of mild symptoms. However,
these medications must be used with caution in people with renal impairment.
Tricyclic medications are used in the
management of neuropathic pain, but their use is restricted because of the frequency and severity of side effects, which include
dry mouth, blurred vision, cardiac arrhythmias, sedation, urinary retention, constipation, and postural hypotension. Amitriptyline
and imipramine are some of these drugs.
Selective serotonin reuptake
Some studies support the use of selective serotonin
reuptake inhibitors (paroxetine and citalopram) in dosages of up to 40 mg/day.
Anticonvulsants have been used in the
management of neuropathic pain for many years, but there is limited evidence to support the efficacy of phenytoin and carbamazepine.
Gabapentin is now widely used for neuropathy symptoms and its efficacy
has been confirmed. However, the side effects are a problem, although they seem to be less than those of the tricyclics. They
include sedation, dizziness, headache, and weight gain.
A newer drug, pregabalin,
may be a useful addition to the anticonvulsants therapy.
sodium valproate have also confirmed efficacy in randomized, controlled trials.
Local anesthetic arrhythmic agents
Mexiletine, an oral
analog of lidocaine, has been reported to be of benefit in some studies, but it is not widely used because of side effects
and the need for heart function monitoring with its use.
Some studies suggest
that the use of a 5% lidocaine patch in diabetic polyneuropathy is associated with relief of neuropathic symptoms without
serious adverse effects.
Opioids have not traditionally been used in the management of diabetic neuropathic pain, but tramadol has been confirmed
to be effective and it can be used safely for up to 6 months of sustained pain relief as well as controlled-release oxycodone.
The side effects of both drugs include somnolence, nausea, and constipation; addiction is also a problem.
Methadone, an opioid that has been widely used as a medication to prevent withdrawal in people
addicted to drugs, has recently proved to help in the treatment of neuropathic pain.
Topical and physical treatments
Capsaicin, an alkaloid
naturally found in red hot pepper, reduces chemically induced pain. This agent works better for those with localized discomfort
rather than those with widespread generalized pain.
Local application of
isosorbide dinitrate spray seems to be effective in relieving overall pain and burning discomfort.
Acupuncture. Different studies support the use of acupuncture and it seems that the effects can last for several
months, but there is a need for controlled studies to confirm these results.
physical therapies have been used, like percutaneous nerve stimulation, static magnetic field therapy, low-intensive laser
therapy, and monochromatic infrared light. These therapies need to be further studied.
New potential therapies currently being studied:
Parenteral administration of alpha-lipoic-acid, an antioxidant, has been shown to be effective in the management
of painful neuropathies.
Also, elevated protein kinase C activity is believed
to play an important role in the causes of diabetic microvascular complications and could be helpful with painful neuropathies.
All people with diabetes, regardless of their type of diabetes, duration of diabetes, or age, require a careful clinical
examination of legs and feet at least once a year.
Any person with diabetic
neuropathy must be considered to be at potential risk of foot ulceration or injury, and should receive preventive education
and referral to a podiatrist as necessary.
November 9, 2005
· Lewis Hays, Coleen Reid, Michelle Doran, and
Karyn Geary. Use of Methadone for the Treatment of Diabetic Neuropathy. Diabetes Care 2005: 28; 485-487.
Jennifer B. Marks. The Forgotten Complication. Clin. Diabetes 2005 23: 3-4.
· Andrew J.M. Boulton. Management of Diabetic
Peripheral Neuropathy. Clin. Diabetes 2005 23: 9-15.