Q. I was given gabapentin in the hospital following surgery. A few days post-surgery, the doctor removed drains along with a pressure bandage. At that point, I began to feel very light-headed and had awful diarrhea.

At home, I had several additional episodes of dizziness and diarrhea. On the fourth day home from the hospital, I began to feel extremely light-headed and called to my husband. He caught me as I was passing out, cracking my head on the kitchen counter as I went down.

My primary care physician checked me thoroughly and immediately took me off gabapentin. I haven’t had any issues since and will never take that drug again.

A. Doctors are turning to gabapentin for relieving pain after surgery, so that they can prescribe fewer opioids. Dizziness is a fairly common side effect of the drug, and diarrhea has also been reported.

A recent review in JAMA Internal Medicine (Nov. 1, 2022) criticized the prescribing of gabapentin to control pain in older adults after surgery. The authors noted that this medication is associated with delirium, dizziness, visual problems and pneumonia. You were fortunate that your fall did not result in serious complications.

Q. Thank you for writing to suggest that if fungal remedies don’t work on stubborn toenail fungus, the culprit may not be a fungal infection. Apparently, a bacterial infection could cause similar symptoms.

For 20 years, I tried a lot of remedies on my thick, ugly, yellow, crumbling toenails. Nothing, including Vicks VapoRub, worked until you suggested trying Neosporin. I applied it at bedtime, and the overnight result was astonishing! The next morning, my nails were pink, and the crumbling yellow-white crud was gone! My podiatrist was also amazed. I use it regularly now.

A. We have been amazed by the number of messages we have received just like yours. Many people who could not get rid of their nail “fungus” with home remedies or anti-fungal agents report success with topical neomycin plus polymyxin B (Neosporin ointment). That suggests bacteria may be partially responsible for some infections (Journal of the American Podiatric Medical Association, March 1, 2021). Thank you for letting us know that this approach was successful.

Q. My son kept his acne under control with our dermatologist’s recommendation: niacinamide gel and a prescription topical Retin-A cream, alternating with benzoyl peroxide. The benzoyl peroxide and the niacinamide were over the counter.

The doctor said that niacinamide is an anti-inflammatory which often helps with skin conditions. When my son ran out for a week, the acne started coming back, so I know it really made a difference.

A. Acne often responds well to topical combination therapy. Tretinoin (Retin-A) was introduced over 40 years ago and remains a key acne treatment. Skin irritation, redness and sensitivity to sunlight are possible side effects.

Benzoyl peroxide can cause redness, burning, itching and peeling. Niacinamide is a kind of B vitamin and does indeed have anti-inflammatory activity.

To learn more about acne in teenagers and adults, you may find our “eGuide to Acne Solutions” of value. It describes an anti-acne diet and a variety of other treatments. You will find this online resource under the Health eGuides tab at www.PeoplesPharmacy.com.

In their column, Joe and Teresa Graedon answer letters from readers. Write to them in care of King Features, 628 Virginia Drive, Orlando, Fla., 32803, or email them via their website: www.PeoplesPharmacy.com. Their newest book is “Top Screwups Doctors Make and How to Avoid Them.”