What Is "Neuropathy Secondary To Drugs"?

Today's post from nlm.nih.gov (see link below) talks about a condition called 'Neuropathy second to drugs'. It's neuropathy as we all know it but the causes are more specifically drug-related rather than anything else. I know, why do they have to create yet another term for something that can be easily described in plain English! However, you may come across it, or hear it from your doctor and now at least you'll know what it means. Actually, the article is helpful in that it provides a list of drugs to watch out for. If you find you're showing symptoms of neuropathy, or your neuropathy is getting worse, while on these drugs, you should talk to your doctor - there are nearly always alternatives which don't have nerve damage as a possible side effect. However, bear in mind that everyone is different and reacts differently to a particular drug so hearsay from a friend may not apply in your case.

 
Neuropathy secondary to drugs
Medline Plus  A service of the U.S. National Library of Medicine

Neuropathy secondary to drugs is a loss of sensation or movement in a part of the body due to nerve damage from a certain medicine.
Causes

The damage is caused by the toxic effects of certain medications on the peripheral nerves (nerves that are not in the brain or spinal cord). There may be damage to the axon part of the nerve cell, which interferes with nerve signals.

Most commonly, many nerves are involved (polyneuropathy). This usually causes sensation changes that begin in the outside parts of the body (distal) and move toward the center of the body (proximal). There may also be changes in movement, such as weakness.

Many medications may affect the development of neuropathy, including:

Heart or blood pressure medications
Amiodarone
Hydralazine
Perhexiline
Drugs used to fight cancer
Cisplatin
Docetaxel
Paclitaxel
Suramin
Vincristine
Drugs used to fight infections
Chloroquine
Isoniazid (INH) -- used against tuberculosis
Metronidazole (Flagyl)
Nitrofurantoin
Thalidomide (used to fight leprosy)
Drugs used to treat autoimmune disease
Etanercept
Infliximab
Leflunomide
Drugs used to treat skin conditions (Dapsone)
Anticonvulsants (phenytoin)
Anti-alcohol drugs (disulfiram)
Drugs to fight HIV
Didanosine (Videx)
Stavudine (Zerit)
Zalcitabine (Hivid)
Arsenic
Colchicine
Gold

Symptoms
Numbness, loss of sensation
Tingling, abnormal sensations
Weakness

Sensation changes usually begin in the feet or hands and move inward.
Exams and Tests

A brain and nervous system examination will be done.

Other tests include: 
 
Blood tests to check levels of the medication (even normal blood levels of certain drugs may be toxic in elderly or certain other persons)
EMG and nerve conduction test of the electrical activity of nerves and muscles
Treatment

Treatment is based on the symptoms and how severe they are. The medication causing the neuropathy may be stopped, reduced in dose, or changed to another medication. (Never change any medication without first talking to your health care provider).

The following medications may be used to control pain:
 
Over-the-counter pain relievers may be helpful for mild pain (neuralgia).
Phenytoin, carbamazepine, gabapentin, pregabalin, duloxetine, or tricyclic antidepressants such as nortriptyline may reduce the stabbing pains some people experience.
Opiate pain relievers, such as morphine or fentanyl, may be needed to control severe pain.

Whenever possible, avoid or reduce medication use to lessen the risk of side effects.

If you have lost sensation, you may need to take safety measures to avoid injury. 

Outlook (Prognosis)

Many people can partially or fully return to their normal function. The disorder does not usually cause life-threatening complications, but it can be uncomfortable or disabling.
Possible Complications
Inability to function at work or home because of permanent loss of sensation
Pain with tingling in the area of the nerve injury
Permanent loss of sensation (or rarely, movement) in an area
When to Contact a Medical Professional

Call your health care provider if you have a loss of sensation or movement of any area of the body while taking any medication.

Prevention

Your health care provider will closely monitor your treatment with any medication that may cause neuropathy. The goal is to keep the proper blood level of medication needed to control the disease and its symptoms while preventing the medication from reaching toxic levels.
References

Katirji B, Koontz D. Disorders of peripheral nerves. In: Daroff RB, Fenichel GM, Jankovic J, Mazziotta JC. Bradley’s Neurology in Clinical Practice. 6th ed. Philadelphia, PA: Elsevier Saunders; 2012:chap 76.

Weimer LH, Sachdev N. Update on medication-induced peripheral neuropathy. Curr Neurol Neurosci Rep. 2009;9(1):69-75.
Update Date: 2/27/2013

Updated by: Luc Jasmin, MD, PhD, Department of Neurosurgery, Cedars Sinai Medical Center, Los Angeles and Department of Anatomy, University of California, San Francisco, CA. Review provided by VeriMed Healthcare Network. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.

http://www.nlm.nih.gov/medlineplus/ency/article/000700.htm