Q. I have been working with a nutritionist who trained as a pharmacist. She has been very helpful.
I emailed her a list of my husband’s medications and asked which ones could cause erectile dysfunction. She said it could be enalapril with hydrochlorothiazide.
She recommended L-arginine, an amino acid that increases nitric oxide and boosts blood flow. The instructions are to take 500 mg twice a day, preferably on an empty stomach. Can you tell me more?
A. L-arginine is a natural compound that is found throughout our bodies and in foods such as nuts, seeds, whole grains, seafood and chocolate. It is an amino acid that is a building block for proteins, and as you have said, it is important for nitric-oxide production.
Nitric oxide relaxes blood vessels and improves circulation. Drugs for erectile dysfunction (ED), such as Cialis and Viagra, work through the release of nitric oxide.
As a dietary supplement, L-arginine has a mixed record of success for ED. In one controlled trial, it worked no better than placebo (Urologia Internationalis, No. 4, January 2000); in another, it only helped men whose own nitric-oxide production was subpar (BJU International, February 1999).
Q. After my migraines began flaring up weekly, I started taking riboflavin (vitamin B-2) daily. Ten weeks into this regimen, I have only had two really bad headaches.
I still have Maxalt as a backup, but I haven’t needed to take it in a few months. The only side effect I’ve had from the B-2 is bright-yellow urine. Compared to the migraines, I’ll take it!
A. Riboflavin has been used as a way of preventing migraines for many years (Neurology, February 1998). A review of research suggests that it may work even better in combination with Coenzyme Q10 (Headache, Supplement s2, October 2012). While riboflavin will turn urine almost fluorescent yellow, other side effects are rare.
In their column, Joe and Teresa Graedon answer letters from readers. Write to them in care of this newspaper or email them via their Web site: www.PeoplesPharmacy.com. Their newest book is “Top Screwups Doctors Make and How to Avoid Them.”
2014 King Features Syndicate, Inc.