Neuropathy refers to damage affecting peripheral nerves, nerves outside the brain and spinal cord. These nerves transmit information between the central nervous system and the rest of the body. When damaged, their communication with the brain is interrupted, leading to symptoms.
It commonly results in weakness, numbness, and pain, often in the hands and feet. Certain medications can cause nerve damage. Understanding neuropathy’s signs and associated drugs helps individuals take appropriate next steps.
Recognizing Neuropathy Symptoms
Neuropathy symptoms vary depending on the affected nerves. They often begin subtly and progress over time.
Sensory Neuropathy
Sensory nerves, responsible for sensations like touch and pain, can be affected. Symptoms include gradual numbness, prickling, or tingling, often starting in the feet or hands and spreading upwards. Sharp, jabbing, throbbing, or burning pain, and extreme sensitivity to touch are also common. A diminished ability to feel pain or temperature, especially in the feet, is common.
Motor Neuropathy
Motor nerves control muscle movement, and damage to these nerves results in motor neuropathy. Symptoms can include muscle weakness, twitching, and cramps. Individuals might experience a loss of balance and coordination, difficulty walking, or reduced dexterity. Muscle thinning or wasting can occur, especially in the feet, lower legs, and hands.
Autonomic Neuropathy
Autonomic nerves regulate automatic bodily functions such as blood pressure, heart rate, digestion, and sweating. While less common with drug-induced neuropathy, damage to these nerves can lead to symptoms like dizziness or fainting due to sudden drops in blood pressure. Digestive issues, sweating problems, urinary problems, or sexual difficulties can also occur.
Medications Associated with Neuropathy
Many medications can lead to neuropathy, with risk and severity depending on the drug, dosage, and treatment duration. Individual susceptibility varies, and not everyone develops nerve damage. Awareness of these associations aids monitoring and early intervention.
Chemotherapy Drugs
Chemotherapy drugs are a common cause of drug-induced peripheral neuropathy. These agents can damage nerve cells. Common culprits include platinum-based drugs (e.g., cisplatin, oxaliplatin), taxanes (e.g., paclitaxel, docetaxel), and vinca alkaloids (e.g., vincristine). Proteasome inhibitors like bortezomib and immunomodulatory drugs such as thalidomide can also cause neuropathy.
The incidence of neuropathy in chemotherapy patients can range from 19% to over 85%. In some cases, symptoms may worsen even after treatment stops, a phenomenon known as “coasting.”
Antiretroviral Medications
Antiretroviral medications, particularly older drugs used to treat HIV, have been associated with neuropathy. Nucleoside reverse transcriptase inhibitors (NRTIs) like didanosine (ddI), stavudine (d4T), and zalcitabine (ddC) are known to cause a painful neuropathy. Newer antiretrovirals are less likely to cause this side effect, but older agents highlight medication’s potential to impact nerve health.
Antibiotics
Certain antibiotics can lead to nerve damage, especially with high doses or extended use. Fluoroquinolones (e.g., ciprofloxacin, levofloxacin) have been linked to peripheral neuropathy, with symptoms sometimes persisting after the drug is discontinued. Metronidazole and isoniazid, used for infections, are also recognized causes. Other implicated antibiotics include nitrofurantoin, dapsone, and ethambutol.
Immunosuppressants
Immunosuppressants, used for autoimmune diseases or organ transplants, can cause nerve issues. Thalidomide is known to induce neuropathy. Cyclosporine and tacrolimus, used to prevent organ rejection, have been associated with neurotoxicity, including peripheral neuropathy. Tumor necrosis factor-alpha (TNF-α) inhibitors (e.g., adalimumab, infliximab, etanercept), used for inflammatory conditions, have also been linked to various neuropathies.
Cardiovascular Medications
Cardiovascular medications rarely cause neuropathy. Amiodarone, an antiarrhythmic, can cause sensory and motor deficits with prolonged or high-dose use. Hydralazine, for high blood pressure, is also a potential cause. Statins, widely prescribed to lower cholesterol, have shown a slight increase in neuropathy incidence with long-term use.
Other Medications and Substances
Other medications and substances can also contribute to neuropathy. Excessive vitamin B6 (pyridoxine) from supplements can lead to sensory neuropathy. Colchicine (for gout) and certain anticonvulsants like phenytoin have also been linked to nerve damage.
Steps to Take for Suspected Neuropathy
If you suspect neuropathy symptoms, consult a healthcare professional. Self-diagnosing or changing prescribed medications without medical guidance can be harmful. A doctor can accurately assess symptoms and determine the cause.
When consulting your doctor, provide a comprehensive medical history, including all current medications. This information is crucial to evaluate potential drug-induced neuropathy and differentiate it from other causes. Also, mention any pre-existing conditions, as some can increase neuropathy risk.
Prescription drugs
Over-the-counter medications
Supplements
Herbal remedies
Your doctor will likely perform a physical examination and may order tests to confirm diagnosis and identify the cause. If medication is the cause, your healthcare provider can discuss strategies. These may include adjusting the implicated drug’s dosage, switching to an alternative medication, or managing symptoms. Early detection and management prevent further nerve damage and improve outcomes.