People’s Pharmacy: Cold sores disappear quickly with antiviral pills

Q. I have had cold sores for years, generally when I’ve been stressed. While working, I had good insurance and I always used prescription Zovirax cream. Now that I’m retired, this cream is not covered by my Medicare. The cost for a small tube requires a home mortgage.

My dermatologist recommended two prescription valacyclovir pills every 12 hours for one day. Comparing the pills with the cream, he said it’s like taking a gun to a knife fight – an obvious reference to Indiana Jones. He is right on. At the first sign of a tingle, I take two pills, and the cold sore is gone the next day. The cream used to take several days to get rid of it, and the pills cost a lot less than the cream.

A. Thank you for the testimonial. Until you alerted us, we had no idea that Zovirax cream was so pricey. In our area, we found it would cost more than $900 for a 5-gram tube. Even the generic acyclovir cream is unbelievably expensive at more than $800.

Cold sores are caused by herpes simplex virus type 1 (HSV1). There’s no cure for this virus that shows up as a lesion when the immune system isn’t able to hold it back. But oral medications like acyclovir and valacyclovir can quickly heal the lesion. It makes sense to use the tablets as you do. The cost is minimal, a few dollars for a day’s supply.

Q. I read on your website about using Selsun Blue to help control eczema. Intrigued, I tried it. To my surprise, it has greatly reduced the itching, and I now have almost none. This is after many years of applying many prescription and nonprescription products.

Since I use it on my legs in the shower, it is difficult to keep it from washing off. I’ve searched for an ointment or cream that could be used outside the shower. I wonder if you are aware of such a product.

A. The original Selsun Blue dandruff shampoo contains selenium sulfide. We have heard from many readers that this ingredient can be helpful against rosacea when diluted as a face wash. People rinse it off after washing.

There are prescription-strength (2.25% to 2.5%) formulations of selenium sulfide for seborrheic dermatitis and tinea versicolor (a fungal infection of the skin). They need to be rinsed off just like shampoo. If you are getting good results with an OTC product like Selsun Blue, you might find that safer and more cost effective.

Q. I have been taking a PPI daily for many years to treat Barrett’s esophagus. During that time, I have been struggling with symptoms of low thyroid activity even though I take levothyroxine conscientiously. My TSH is elevated, and my doctor keeps increasing my dose of levothyroxine. Do you have any suggestions?

A. There is a strong likelihood that the proton pump inhibitor you are taking for acid reflux is interfering with absorption of your thyroid medicine (Clinical Drug Investigation, March 2015).

There are two possible solutions to this problem. Your gastroenterologist could find a different way to treat the Barrett’s esophagus. Alternately, your doctor could prescribe a soft-gel form of levothyroxine (Tirosint). Unfortunately, Tirosint can be pricey if your insurance does not cover it.

You can learn more about this and other interactions with levothyroxine in our eGuide to Thyroid Hormones. You will find it in the Health eGuides section at peoplespharmacy.com.