A group of multiple myeloma experts from the International Myeloma Working Group recently published a review of management strategies for drug-induced peripheral neuropathy in patients with multiple myeloma.

This Beacon article, the third in a three-part series, summarizes the experts’ recommendations for prevention of peripheral neuropathy as well as future steps toward better management of the condition.

The first article in the series describes peripheral neuropathy and summarizes the symptoms of drug-induced neuropathy as well as the risk of developing neuropathy associated with myeloma therapies.  The second article summarizes the experts’ recommendations for the treatment of drug-induced peripheral neuropathy.

Prevention

Because there are currently no curative therapies for drug-induced peripheral neuropathy in myeloma patients, the authors of the recent review state that prevention is a key strategy for preserving patients’ quality of life as well as their future treatment options.

Prevention may be achieved through early detection and monitoring as well as by taking certain supplements and medications.

Early Detection And Monitoring

The International Myeloma Working Group experts recommend that all myeloma patients receive clinical assessment for signs and symptoms of peripheral neuropathy prior to and during treatment with neurotoxic anti-myeloma drugs. This would enable physicians to detect and manage peripheral neuropathy during the early stages of the disease before it becomes more severe.

Ideally, according to the experts, patients should be assessed with each dose of anti-myeloma therapy that they receive. Moreover, patients who have a history of peripheral neuropathy should be regularly monitored after receiving a stem cell transplant because symptoms may become worse even several months after the transplant.

The experts state that assessments performed by a neurologist after each cycle of therapy may also be helpful for detecting and managing drug-induced peripheral neuropathy in myeloma patients.

They suggest that neurological assessments may help neurologists detect early cases of peripheral neuropathy that may otherwise be undetected with regular assessments by the patient, nurses, or the patient's oncologist. In one study, 54 percent of myeloma patients who had a neurological assessment showed neuropathy-related symptoms at diagnosis, compared to only 20 percent of myeloma patients who had an assessment by a nurse or oncologist.

Additionally, neurological assessments involving electromyograms (EMGs) can be used to determine whether a patient’s peripheral neuropathy is caused by therapy or by the myeloma itself.

Neurologists can also determine the severity of a patient’s peripheral neuropathy and begin treatment of the disorder with anti-seizure or anti-depression medications.

The experts acknowledge the need for more sensitive tools to assess the symptoms of drug-induced peripheral neuropathy specifically in myeloma patients.

To this end, they propose the development of a “visual analog scale” that patients can use to compare their current symptoms to their symptoms during a previous medical visit. This method would allow physicians to quickly detect any improvement or worsening of symptoms related to peripheral neuropathy.

“It is potentially more objective to formalize peripheral neuropathy assessment with [a visual analog scale]. This may more reliably lead to caregivers being alerted to symptoms,” commented Dr. Paul Richardson of the Dana Farber Cancer Institute in Boston and the lead author of the review.

The experts also suggest that a more detailed understanding of the factors that predispose myeloma patients to peripheral neuropathy is needed to identify patients who are at risk of developing the disorder.

Supplements And Medications

According to the experts, drug-induced peripheral neuropathy may also be prevented by taking vitamin supplements (including vitamins B1, B6, B12, E, and folic acid), magnesium supplements, amino acid supplements, dietary potassium, fish oils, omega-3 fatty acids, evening primrose oil, and flax seed oil. 

Anti-seizure medications such as gabapentin (Neurontin) and Lyrica (pregabalin) and anti-depression medications such as amitriptyline (Elavil) and Cymbalta (duloxetine) may also help prevent peripheral neuropathy.

However, the experts acknowledge that further studies are needed to evaluate the effects of these supplements and medications in preventing peripheral neuropathy induced by specific anti-myeloma drugs.

Future Directions

The experts conclude their review by expressing the need for additional studies on drug-induced peripheral neuropathy in myeloma patients in order for physicians to be able to better manage and prevent the disorder.

Specifically, they express the need for further investigation of peripheral neuropathy in myeloma patients who receive different combinations of therapies.

They also recommend more research on the causes, risk, and severity of peripheral neuropathy in patients who are treated with newer, investigational anti-myeloma drugs.

Moreover, a more detailed understanding of the risk factors for peripheral neuropathy as well as better tools for identifying and monitoring the disorder are needed.

“We need to better understand who is at risk [of developing peripheral neuropathy] and why so in order to potentially tailor therapy [according to patients’ needs],” said Dr. Richardson.

Finally, the experts recommend further research on the specific benefits of certain drugs for the treatment of drug-induced peripheral neuropathy specifically in patients with multiple myeloma.

For more information, please see the article in the journal Leukemia (abstract).