DEAR DR. ROACH: I was in excellent health until December 2020, when I was admitted to the hospital with high-risk multiple myeloma (MM). I’ve been participating in a Phase 2 clinical trial since January 2021, and I was fortunate to achieve minimal residual disease (MRD)-negative status in November 2023 — a milestone that is reached by only 10% of over 20 participants.

However, as a side effect of four years of treatment, including Velcade injections (16 total), I’ve developed neuropathy, mainly in my feet. My primary issue is overall numbness and a lack of feeling in my feet. This creates a sensation of swelling and leads to a lack of confidence in my balance and walking.

I’m seeking advice on how to treat this condition. I previously tried gabapentin for three months in 2021 without success, and it was discontinued then. I also underwent ultrasound treatments for a year, which provided some relief, but the provider went out of business. I’m unsure about the most effective and reliable next steps. They talk about pink Himalayan salt; do you think this would be effective?

— D.P.

ANSWER: It’s very good news that you have reached MRD-negative status, which gives you an excellent prognosis for being progression-free — and for your overall survival. Unfortunately, it’s come at a cost of side effects from chemotherapy.

Bortezomib (Velcade) is an effective medication for MM, but it is well-known to cause peripheral neuropathy, which specifically damages the small nerve fibers and often causes pain and burning sensations. One treatment that is moderately effective for these symptoms is pregabalin, which is related to the gabapentin that didn’t work for you.

Unfortunately, my experience is that treating numbness is harder than treating pain or burning. Numbness can lead to difficulty walking, as your body may not know exactly where your feet are or when you’re touching the ground. In my literature review, I found that an unrelated medicine, duloxetine, can sometimes help with numbness, but I personally haven’t seen success.

I see Himalayan salt marketed for many conditions, but it’s really just salt with tiny amounts of minerals, such as the iron that gives it its pink color. There isn’t any reason to think that it’d be effective, and there’s no evidence for it.

Your best bets are protective shoes, daily inspections of your feet to look for injuries, and physical therapy to help with balance, coordination and strength.