Alternative Names drug-induced polyneuropathies, drug-induced neuropathy
Definition Neuropathy secondary to drugs is a condition in which there is a loss of sensation in a part of the body, associated with the use of a medication that can damage nerves.
What is going on in the body? Neuropathy is caused by toxic effects of certain medications on the peripheral nerves, or nerves that are not in the brain or spinal cord. The normal function of the nerves is blocked due to the damage to part of the nerve. The person experiences abnormal sensations, including numbness or chronic pain. Examples of medication that may cause neuropathy include:
heart or blood pressure medications, such as amiodarone or hydralazine
chemotherapy medication used to fight cancer, such as vincristine or cisplatin
antibiotics used to fight infection, such as metronidazole, isoniazide, and nitrofuantoin
anticonvulsants used to prevent seizures, such as phenytoin
medications used to prevent alcohol use, such as disulfiram
What are the signs and symptoms of the disease? Symptoms of neuropathy include:
These sensation changes usually begin in the hands or feet, and progress toward the centre of the body.
What are the causes and risks of the disease? Neuropathy is not contagious.
How is the disease diagnosed? A complete history and physical examination is needed to diagnose neuropathy. Special studies such as electromyography and nerve conduction velocity tests can measure how fast signals travel down the nerves.
What are the long-term effects of the disease? The major long-term effect is chronic pain, which can be disabling. A person with neuropathy is at risk for injury because of a decreased ability to feel.
What are the treatments for the disease? Once the neuropathy is diagnosed, the medication causing the problem may be stopped, reduced in dose, or changed to another medication.
Pain caused by neuropathy may be treated with medications that are normally used to control seizures, depression, or pain. Sometimes topical agents on the skin are used. These agents may actually increase the pain in the beginning of treatment. Then, a person may feel a decrease in the pain associated with the neuropathy.
A person with loss of sensation should be instructed on safety measures to prevent injury. He or she should regularly examine the affected area for injury and seek treatment as needed.
What are the side effects of the treatments? Side effects depend on the medication used, but may include allergic reactions and drowsiness.
What happens after treatment for the disease? Unfortunately, treatments are not very effective. Only about 25% of each treatment may work each time it is tried.
How is the disease monitored? The doctor will monitor blood levels of medication used that may cause neuropathy. The goal is to maintain the amount of medication needed to treat the condition, while preventing toxic levels of the medication.
Author: Gail Hendrickson, RN, BS Reviewer: HealthAnswers Australia Medical Review Panel Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia Last Updated: 1/10/2001 Contributors Potential conflict of interest information for reviewers available on request