Topical Drug Combos May Be Beneficial for CIPN

Chemotherapy-induced peripheral neuropathy (CIPN) is a common adverse effect for patients undergoing cancer treatments, and while certain topical agents may help with the symptom, more research is needed, explained Richard Lee, MD.

Lee, who is the Cherng Family Director's Chair, Center for Integrative Oncology, at City of Hope, conducted a review of research conducted on topical agents for CIPN. The results were presented at the 2024 Society for Integrative Oncology (SIO) Annual Conference and later discussed in an interview with Oncology Nursing News.

Oncology Nursing News: Can you provide a brief overview on your abstract on peripheral neuropathy from SIO?

Lee: So this year, at the SIO 2024 conference, our research team presented an abstract which did a systematic review of the literature looking at topical agents for the treatment of chemotherapy-induced peripheral neuropathy, or CIPN. This is a, unfortunately, a common neurological side effect that occurs with some types of chemotherapy, and in some instances, it can become chronic.

What we were able to identify were 6 randomized control trials that looked at different types of topical agents. Some of these were single agent using different types of essential oils and some more combination. Out of the 6 studies, we did identify 2 that seemed to have positive results. The first was a combination of different agents, put together baclofen, amitriptyline, and ketamine, and they called it BAK combination.

Patients seemed to show benefit in a large randomized trial of over 200 patients in the single-agent area, different things were tested, such as CBD, peppermint geranium, black pepper, Rosemary oil combination, and also a crepe ginger essential oil. And what we found was this crepe ginger essential oil did show some initial benefit, although it's a relatively small study, and so I think that these topical agents have the advantage of not being ingested, and it's easier to utilize with fewer side effects.

We still need to do more research to really understand if these agents are appropriate and who might most be beneficial for.

There was one other study that was positive, which was the CBD study, also topical CBD, in one study, did show some benefit, although I think there's growing mixed data, but I think there's another publication recently that didn't show benefit.

Wheat factors would you consider when assessing a patient's suitability for topic topical agents for CIPN?

I don't think we really know yet, just because there's so few studies in this area, and so I think we need to do additional, larger randomized controlled trials of these different agents, like the crepe ginger and the CBD, or the combination of baclofen and amitriptyline and ketamine.

The last one was the largest, so that one seems to be more reasonable to consider, although that combination is not easy to find, you wouldn't find it premade. It would have to be pharmacy that would have to make that combination. So I think that limits its applicability for patients. So I think we just need more research, looking at these different initial studies and figure out which one might be best, and then also for which patient it might best work for.

With these promising yet mixed results, are you telling patients that this is something they can and should use, or are we still waiting for more research?

I think it's still a little bit preliminary and not quite ready to be utilized as standard of care. I do think if you have patients who might have already tried standard of care options and not getting enough relief, this could be something you consider. However, I think we need to inform our patients that the data is still preliminary, and so we don't really know for sure which agent and for which patient quite yet.

What are current standard of standards of care for treating chemotherapy induced peripheral neuropathy, and why do we need more?

Early on, even before [CIPN] develops, we need to be monitoring patients very carefully while they're on active treatment. So I think that strategy of close monitoring and prevention is probably the best strategy in regards for treatment. The only medication that's been shown in clinical research is duloxetine, and that's been shown to help with the symptoms.

There are other agents with more mixed results, such as gabapentin, as commonly utilized, although the data is not as robust as with duloxetine. There are ongoing clinical trials looking at things like acupuncture, which is shown promise, but again, I think it's still a little bit preliminary in terms of which patients and how effective it might be.

Overall, what should oncology nurses and advanced practice providers know about CIPN and its management?

The most important aspect is talking with your patients about this symptom so that they're aware and making sure that if the symptoms do develop, they communicate that early and regularly with treatment.

Have a discussion that if it does develop, oftentimes, it's temporary, and so after we stop the chemotherapy that's causing this, it may actually recover on its own. So that is something to keep in mind.

So many patients will usually feel better within the first 3 to 6 months. If it does become chronic, that's where we need to think about more standard options, and then potentially, if that doesn't help enough, to think about some of these other strategies, like some of the topical agents we talked about.

Reference

Hoang Tran P, Fertal JC, Ku S, et al. A Scoping Review of the Efficacy of Topical Agents for Chemotherapy-Induced Peripheral Neuropathy. Presented at: Society for Integrative Oncology 2024 Conference. October 25-27, 2024. Costa Mesa, California.