Dear Dr. Roach: In March 2023, my 94-year-old mother had a shingles episode on the right side of her neck, head, ear and (to a lesser degree) right cheek. The active blisters lasted about three weeks. Since then, she’s been experiencing continued neuropathy that involves itchiness, a sense of desperation, and some pain. She’s been prescribed gabapentin and has been taking two pills per day that are 300 mg each. However, they don’t seem to help much. Her acupuncturist has indicated that gabapentin may not be the answer for her.
Her other medications include duloxetine. She has Alzheimer’s, diabetes, a history of falls, and hypothyroidism. She’s had three mini strokes and been diagnosed with congestive heart failure. Is there anything else that can help alleviate her condition? Will the neuropathy ever go away?
K.B.
Your mother unfortunately developed a complication of shingles called postherpetic neuralgia (PHN). The pain varies from annoying to excruciating, and itching can sometimes be worse than the pain. Both the pain and itching can lead to desperation. Combined with Alzheimer’s, it must be heartbreaking to see her in so much discomfort.
The natural history of PHN is variable, but as a general rule, the older a person is when they develop shingles, the more likely they are to develop PHN. The longer it tends to last as well. Women are more likely to develop PHN, and I have read estimates that somewhere between 13% to 30% of people over 80 with shingles will develop PHN.
Now that she’s had symptoms for over a year, she has about a 50% chance of recovery during the next year. I don’t know of any treatment that will improve the likelihood of her recovery. However, both the gabapentin she is on and duloxetine (an antidepressant often used to help with pain) may have benefit in relieving symptoms.
I often see patients like your mother being treated with moderate doses of gabapentin. She is taking 600 mg daily, but in the study that got gabapentin approved for PHN by the Food and Drug Administration, the researchers had a goal dose of 3,600 mg per day! This dose can be very sedating, and it takes a long time of slowly titrating the dose up for most people to tolerate it.
Some people (especially older people) just can’t tolerate such a high dose. However, it’s worth a try. Even 300 mg three times daily is likely to be significantly more effective than what she is currently on. If she can tolerate it, her doctor might slowly increase the dose further. I always increase the nighttime dose before the other doses, since it will make people sleepy at a time when it’s a good thing.
Finally, it’s too late for your mother, but older people who have not had the newer two-dose shingles vaccine (Shingrix) should get it, even if they had the old one-dose vaccine (Zostavax) or had shingles in the past. The downsides of the vaccine (i.e., a sore arm, or a day or so of feeling under the weather) is absolutely worth the benefit of an over 90% reduction of the risk of PHN, in my opinion.
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