When The Drugs You Take For Other Conditions Can Cause Neuropathy As A Side Effect

Today's extensive post from medindia.net (see link below) looks in detail at one of the great ironies associated with nerve damage and that is that some of the drugs we're given to treat other complaints, can very often be the cause of our neuropathy itself. It's so unfair but it's a fact of life and it's up to us, along with our doctors, to carefully examine our whole medication intake so as to avoid interactions which may cause nerve damage. This isn't always as easy as it seems. With cancer treatment for instance, doctors sometimes have to make a choice based on what's going to do us more harm in the long run...chemotherapy drugs which kill cancer cells, or the neuropathy which often results from those very cancer drugs that can save our lives. In most cases however, it's simply a question of being alert to what we put in our bodies. For that we need to do our own research and if necessary, question our doctors carefully to make sure that the drugs they're prescribing won't do us more harm than good. It may be worth reading this article and scanning the list to see if any of the drugs you're taking can cause nerve damage (or make it worse) as a side effect. After that, be brave and ask your doctor some serious questions. There are very often alternatives available which won't damage your nerves any further. If you already have neuropathy, you'll know that putting in the hard work is worth the effort!

Drug-Induced Neuropathy 
Written by Jayashree Thakwani | Medically Reviewed by The Medindia Medical Review Team on May 31, 2018


Overview

Causes

Symptoms and Signs

Diagnosis

Treatment

Risk Factors and Complications

Prevention

Frequently Asked Questions

Glossary

Latest Publications and Research

References 
What is Drug-Induced Neuropathy?  Neuropathy is a disorder in which the peripheral nervous system gets damaged.

The peripheral nervous system is responsible for sending messages from the brain and spinal cord (central nervous system) to the rest of the body. A blood-nerve barrier protects the peripheral nerves. In some patients, genetic and metabolic factors could cause peripheral nerve toxicity which affects the peripheral nervous system.

Neuropathy leads to a loss of sensation or movement in parts of the body.

Peripheral nerve disorder is also known as peripheral neuritis or peripheral neuropathy.

Some commonly used therapeutic medications can cause adverse effects that could include neuropathy. This is known as drug-induced neuropathy. These medications cause nerve damage which may be reversible when the drug is discontinued; or in extreme cases, the nerve damage can be permanent.

Peripheral neuropathy is known as mononeuropathy when only one nerve is affected. In most cases, many nerves are involved; in that case, it is called polyneuropathy.

Some common symptoms can be numbness or tingling, muscle weakness or paresthesia (pricking sensation).

Peripheral neuropathy can be a slowly progressing condition and at times can be severe and debilitating. If diagnosed at an early stage, the progress of peripheral neuropathy can be controlled.
What are the Causes of Drug-Induced Neuropathy? Some medications can be toxic to the nerves and drug-induced neuropathy is caused by such medications. For example, many chemotherapy drugs used in cancer treatment are highly toxic and can kill neurons. Chemotherapy induced peripheral neuropathy (CIPN) is a common adverse effect of many commonly used cancer treatments.



What are the Drugs that are Known to Cause Neuropathy? Some categories of drugs are known to cause neuropathy:

Antimicrobials
Isoniazid
Ethambutol
Nitrofurantoin
Metronidazole
ChloroquineAntineoplastic agents
Vinca alkaloids (vincristine)
Paclitaxel
Cisplatin
DocetaxelBlood pressure or Cardiovascular drugs
Perhexiline
Hydralazine
Amiodarone – a blood pressure medication
Hypnotics and psychotropics
Methaqualone
ThalidomideDrugs for Autoimmune disease
Infliximab
LeflunomideAnticonvulsants
Phenytoin
Carbamazepine
PhenobarbitalDrugs to treat HIV/AIDS
Didanosine
Emtricitabine
Tenofovir

Antirheumatics
Indomethacin
GoldOthers
Disulfiram - used to treat alcoholism
Dapsone - to treat leprosy and severe dermatological conditions
Allopurinol - to treat gout
Thalidomide - to treat multiple myeloma and leprosy
Statins - to lower cholesterol
Colchicine - used to treat goutWhat are the Symptoms and Signs of Drug-Induced Neuropathy? There are three known types of peripheral neuropathy, and the symptoms associated with each vary depending on the type:
Sensory neuropathy - In this type, the sensation is affected due to damage to sensory fibers. Common symptoms include pricking and tingling sensation, numbness particularly in the feet, and loss of balance.
Autonomic neuropathy - Affects the functioning of internal organs. This type results in damage to autonomic nerves which are typically responsible for involuntary movements in the body. These include breathing, heartbeat, bladder function, digestion, swallowing, bowel control, and sexual functions.
Motor neuropathy - In this type, motor nerves in the muscles get affected, and the patient is unable to move muscles as they become weak or experience muscular atrophy. Common symptoms include muscle weakness or paralysis, muscle cramps and foot drop.The common symptoms of peripheral neuropathy include:numbness in the feet and hands, accompanied by tingling or shooting pain
difficulty in walking or losing balance while walking
weakness of limbs
poor gripping power of hands
burning sensation
muscle cramps
a feeling of wearing gloves or stockings, even when not wearing them
inability to feel normal pain
incontinence
breathing difficulties
excessive sweating
excessive sensitivity to touch
non-cardiac tachycardia
problems in sexual performance
How do you Diagnose Drug-Induced Neuropathy? Peripheral neuropathy cannot be diagnosed with a single test.

A thorough investigation of the patient’s medical history is required to understand the symptoms and the likely cause of symptoms.

The physician may advise general blood tests to check diabetes, vitamin deficiencies, liver or kidney dysfunction, metabolic disorders and signs of an abnormal immune system.

More specialized neurological examinations could be conducted to check muscle strength and efficiency of nerve conduction; some of these include Electromyography (EMG) and Nerve conduction velocity test (NCV).

Magnetic Resonance Imaging (MRI) can help understand muscle quality and identify the cause of neuropathy in tumors or herniated discs.

Genetic tests may be suggested to understand the presence of inherited neuropathies.

A skin biopsy may be suggested to diagnose any fiber damage.

Spinal tap (lumbar puncture) test can be conducted to detect infections, tumors or autoimmune disorders like multiple sclerosis. 
What are the Treatment Options for Drug-Induced Neuropathy? Drug-induced neuropathy though uncomfortable and debilitating, is not life-threatening. Symptoms usually go away when the toxic drugs are changed or discontinued or if the dosage is reduced according to the doctor’s advice.

Treatment however is based on the severity of symptoms and may include the following:
Reducing the dose of the causative drug that induces neuropathy
Substituting a less toxic medication
Pain caused due to neuropathy can be treated with two types of medications - anti-depressants and anti-seizure medications; they can be used individually or in combination. At times, the side effects of these medications can be worse than the neuropathy symptoms. Hence, it is important for the physician to evaluate the course of medication for each patient
Morphine, an opiate pain reliever may need to be prescribed to control severe pain
The healthcare provider may advise use of special shoes or footwear



 
What are the Risk Factors and Complications of Drug-Induced Neuropathy?

 The high-risk factors for drug-induced neuropathy include the use of medications to treat the following conditions:

Diabetes mellitus
Alcohol abuse
Vitamin deficiency
Infections such as shingles, hepatitis C, Epstein-Barr virus
Kidney, liver or thyroid disorders
Autoimmune diseases, such as rheumatoid arthritis and lupusComplications could include:
Inability to work because of permanent loss of sensation
Burns and skin trauma - as the person may not feel temperature changes or pain on parts of the body which have become numb
Infections - Loss of sensation in a particular area of the body can lead to infections, as the area can get injured without the person knowledge
Loss of movement or being susceptible to falls - due to lack of balance
How do you Prevent Drug-Induced Neuropathy?Patients who consume drugs known to be neurotoxic must regularly undergo neurological examination and functioning of the motor and sensory nerve conduction.

In general, patients who are under therapeutic treatment and who experience symptoms like pain, muscle cramps, and paresthesia during treatment must undergo neurological testing and motor-sensory nerve conduction.

Drugs must be cautiously used in patients with a risk of developing neuropathy, for example, in patients suffering from renal or hepatic failure, diabetes mellitus or malnutrition.

One must exercise regularly to overcome the occurrence of neuropathy.

The diet should be nutritious and should include fruits and vegetables, ginger and a right quantity of water. Foods containing gluten, refined grains, sugar and saturated fats must be avoided.


Latest Publications and Research on Drug-Induced Neuropathy

 Oral Anti-Vascular Endothelial Growth Factor Drugs and Ocular Side Effects. - Published by PubMed
Retinal ganglion cell loss in neuromyelitis optica: a longitudinal study. - Published by PubMed
Pathophysiology of drug-induce peripheral neuropathy in patients with multiple myeloma. - Published by PubMed
Ontology-based literature mining and class effect analysis of adverse drug reactions associated with neuropathy-inducing drugs. - Published by PubMed
Determinants of anti-retroviral regimen changes among HIV/AIDS patients of east and west Wollega zone health institutions, Oromia region, west Ethiopia: a cross-sectional study. - 

Published by PubMed

Latest Publications and Research on Drug-Induced Neuropathy

J Ocul Pharmacol Ther 2018 Jul 13

Oral Anti-Vascular Endothelial Growth Factor Drugs and Ocular Side Effects.

Fraunfelder FT, Fraunfelder FW

To evaluate possible associations between oral anti-vascular endothelial growth factor (VEGF) drugs and ocular side effects.... Read More

Source: PubMed

J. Neurol. Neurosurg. Psychiatry 2018 Jun 19

Retinal ganglion cell loss in neuromyelitis optica: a longitudinal study.

Oertel FC, Havla J, Roca-Fernández A, Lizak N, Zimmermann H, Motamedi S, Borisow N, White OB, Bellmann-Strobl J, Albrecht P, Ruprecht K, Jarius S, Palace J, Leite MI, Kuempfel T, Paul F, Brandt AU

Neuromyelitis optica spectrum disorders (NMOSD) are inflammatory conditions of the central nervous system and an important differential diagnosis of m... Read More

Source: PubMed
J. Physiol. Pharmacol.

Pathophysiology of drug-induce peripheral neuropathy in patients with multiple myeloma.

Luczkowska K, Litwinska Z, Paczkowska E, Machalinski B

Multiple myeloma (MM) is a disease of unknown, complex etiology that affects primarily older adults. The course of the disease and the patients' survi... Read More

Source: PubMed
J Biomed Semantics

Ontology-based literature mining and class effect analysis of adverse drug reactions associated with neuropathy-inducing drugs.

Hur J, Özgür A, He Y

Adverse drug reactions (ADRs), also called as drug adverse events (AEs), are reported in the FDA drug labels; however, it is a big challenge to proper... Read More

Source: PubMed
BMC Pharmacol Toxicol

Determinants of anti-retroviral regimen changes among HIV/AIDS patients of east and west Wollega zone health institutions, Oromia region, west Ethiopia: a cross-sectional study.

Bokore A, Korme B, Bayisa G

Human Immunodeficiency Virus (HIV) is one of the main causes of morbidity and mortality; because of this it continues to be a major global public heal... Read More

Source: PubMed

Published on May 30, 2018
Last Updated on May 31, 2018

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