Neuropathy secondary to drugs

Neuropathy is injury to one or more peripheral nerves. These are nerves that are not in the brain or spinal cord. Neuropathy secondary to drugs causes a loss of sensation or movement in a part of the body due to nerve damage from taking a certain medicine, combination of medicines, or illicit (street) drugs.

Loss of sensation

Numbness and tingling are abnormal sensations that can occur anywhere in your body, but they are often felt in your fingers, hands, feet, arms, or le...

Image

Read Article Now Book Mark Article

Causes

The damage is caused by the toxic effect of certain medicines or illicit (street) drugs on the peripheral nerves. There may be damage to the axon part of the nerve cell, which interferes with nerve signals. Or, the damage may involve the myelin sheath, which insulates the axons and increases the speed of transmission of signals through the axon.

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. There may also be burning pain.

Proximal

Proximal means nearer to the center (trunk of the body) or to the point of attachment to the body. If another reference point is given, such as the ...

Image

Read Article Now Book Mark Article

Many medicines and substances may lead to development of neuropathy. Examples are listed below.

Heart or blood pressure drugs:

• Amiodarone
• Hydralazine
• Perhexiline

Drugs used to fight cancer (chemotherapy drugs):

• Cisplatin
• Docetaxel
• Paclitaxel
• Suramin
• Vincristine

Drugs used to fight infections:

• Chloroquine
• Dapsone
• Isoniazid (INH), used against tuberculosis

  Tuberculosis

  Pulmonary tuberculosis (TB) is a contagious bacterial infection that involves the lungs. It may spread to other organs.

  

  Image

  Read Article Now Book Mark Article
• Metronidazole (Flagyl)
• Nitrofurantoin
• Thalidomide (used to fight leprosy)

  Leprosy

  Leprosy is a disease caused by the bacterium Mycobacterium leprae. This disease causes skin sores, nerve damage, and muscle weakness that gets worse...

  Read Article Now Book Mark Article

Drugs used to treat autoimmune disease:

Autoimmune disease

An autoimmune disorder occurs when the body's immune system attacks and destroys healthy body tissue by mistake. There are more than 80 autoimmune d...

Image

Read Article Now Book Mark Article

• Etanercept (Enbrel)
• Infliximab (Remicade)
• Leflunomide (Arava)
• Tacrolimus

Drugs used to treat seizures:

• Carbamazepine
• Phenytoin
• Phenobarbital

Anti-alcohol drugs:

• Disulfiram

Drugs to fight HIV/AIDS:

• Didanosine (Videx)
• Emtricitabine (Emtriva)
• Stavudine (Zerit)
• Tenofovir and emtricitabine (Truvada)

Other drugs and substances that may cause neuropathy include:

• Colchicine (used to treat gout)
• Excess pyridoxine (Vitamin B6)
• Arsenic
• Gold
• Illicit drugs (such as methaqualone)
• Glue sniffing
• n-Hexane
• Nitrous oxide (laughing gas)

Symptoms

Symptoms may include any of the following:

• Numbness, loss of sensation

  Numbness

  Numbness and tingling are abnormal sensations that can occur anywhere in your body, but they are often felt in your fingers, hands, feet, arms, or le...

  

  Image

  Read Article Now Book Mark Article
• Tingling, abnormal sensations

  Abnormal sensations

  Numbness and tingling are abnormal sensations that can occur anywhere in your body, but they are often felt in your fingers, hands, feet, arms, or le...

  

  Image

  Read Article Now Book Mark Article
• Weakness
• Burning pain
• Loss of balance
• Trouble walking

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 medicine (even normal blood levels of certain drugs may be toxic in older adults or certain other people)
• EMG (electromyography) and nerve conduction studies (NCS) of the electrical activity of nerves and muscles

  EMG

  Electromyography (EMG) is a test that checks the health of the muscles and the nerves that control the muscles.

  

  Image

  Read Article Now Book Mark Article

  Nerve conduction studies

  Nerve conduction velocity (NCV) is a test to see how fast electrical signals move through a nerve. This test is done along with electromyography (EM...

  

  Image

  Read Article Now Book Mark Article
• Skin biopsy to measure nerve fibers (usually for small fiber neuropathy if EMG and NCS are normal)

Treatment

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

Your provider may suggest the following drugs to help control pain:

• Over-the-counter pain medicines 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.
• Opioid pain medicines such as morphine or fentanyl, may be needed to control severe pain.

There are currently no medicines that can reverse the loss of sensation. If you have lost sensation, you may need to take safety measures to avoid injury.

Ask your provider if there are exercises that can help relieve your symptoms.

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

Complications may include:

• 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 of the body

When to Contact a Medical Professional

Contact your provider if you have a loss of sensation or movement of any area of the body while taking any medicine.

Prevention

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