Hot flashes

Q:After menopause, sex became so uncomfortable that I started taking oral hormone replacement therapy (HRT). It’s helped immensely, but I’ve had two painful kidney stones in the past six months, which I’ve never had before. Could the HRT be to blame?

A:It’s possible. In a study of postmenopausal women published in the Archives of Internal Medicine, investigators found that those who took hormone replacement pills containing estrogen or estrogen in combination with progestin had a 21 percent higher risk of kidney stones than women who took a placebo. The study authors theorize that estrogen triggers the kidneys to release more uric acid into the urine, where it can clump together and form stones. What’s more, the researchers say estrogen may decrease levels of urinary citrate, a compound that prevents the formation of stones.

Since you’ve already experienced two painful episodes, your doctor has likely advised you on dietary strategies that can keep stones at bay, like avoiding nuts, okra, soy and other foods high in oxalates (a component of kidney stones) or limiting meats, shellfish and other foods that contain purines, which can raise uric acid levels. Drinking plenty of water is key, as is avoiding caffeine, which can speed fluid loss to encourage dehydration and prompt stones to form.

But if these diet changes haven’t helped, I suggest making an appointment with your gynecologist. She can recommend alternatives to oral HRT such as estrogen cream, which combats vaginal dryness and the tissue thinning that makes sex uncomfortable after menopause. It delivers lower doses of estrogen than pills do and it’s absorbed directly into tissues of the vagina and bladder only, so it doesn’t trigger stone formation.