Can Valtrex be used as a "day after" drug to prevent genital herpes?

Q: I know Valtrex is prescribed to treat genital herpes. If someone is exposed to a partner with herpes, will taking Valtrex right away destroy any of the virus that may have been acquired before it has a chance to take hold and become dormant? In other words, can Valtrex be used as sort of a "day after" medication?

A: We were intrigued by the idea that Valtrex might protect someone against genital herpes, so we asked the manufacturer, GlaxoSmithKline. GSK has never done a study to investigate this scenario. As a result, there aren't any clinical data to support the use of Valtrex as a "day after" medication or as a prophylactic drug in uninfected individuals whose sexual partners have genital herpes.

Q: My nails break, crack, split, peel and grow very slowly. They're not strong enough to open a soda can.

I take Synthroid for my thyroid, hydrochlorothiazide for blood pressure control, simvastatin for high cholesterol and Prevacid for heartburn. Could any of these affect my nails? Is there anything natural I could take or use? Nail hardeners seem to make the problem worse.

A: Many things may affect nail health. The proper balance of thyroid hormone has an impact. Cholesterol-lowering drugs like simvastatin (Zocor) have been linked to nail changes, and so has the acid-suppressing drug lansoprazole (Prevacid).

Avoid nail hardeners, since they may aggravate the situation. Some readers report that taking a dietary supplement called MSM (methylsulfonylmethane), commonly used for arthritis, may be helpful. Others tell us that moisturizing the nails with products such as Elon, Epilyt or almond oil helps.

For more details on these approaches, check out our guide to hair and nail care. To order a copy, send $3 in check or money order with a long (No. 10), stamped (59 cents), self-addressed envelope to: Graedons' People's Pharmacy, No. H-31, P.O. Box 52027, Durham, NC 27717-2027. It also can be downloaded for $2 at www.peoplespharmacy.com.

Q: I've had an odd experience. I'm 66 and in good health, but my eyesight has deteriorated.

When I take Lunesta to go to sleep, the next day my eyesight is crystal-clear and needs no correction. Then, the following day if I don't take the sleeping pill, my eyes are so blurry and out of focus I have a hard time even with my glasses.

Has anyone else reported this?

A: We have searched the official label information and the medical literature and could find no reference to beneficial effects of Lunesta on vision. Have you considered the possibility that getting a good night's sleep makes the difference?

Write to Joe and Teresa Graedon c/o King Features Syndicate, 888 Seventh Ave., New York, NY 10019, or via their Web site: www.peoplespharmacy.org