I'm taking Zithromax 3 times a week (Monday, Wednesday, and Friday), and have been since December 2002. I believe it's the 500mg dosage. It seemed to help a lot at first, and I think it still is, but as time goes by, I get worse. So though it gets harder, I think the Zithromax is still keeping a lot at bay, so to speak. My only problem, being female, is that constantly being on antibiotics is a hassle as far as yeast infections go. Somewhere after I started it, I started taking two extra pills a day. Both over the counter, called Acidophilous, and the other being AZO yeast, and for the most part, they keep me yeast-infection-free. The only time I have trouble now is when I go on IV antibiotics, because those are much stronger. So if you're having trouble with the yeast issue, ask your doctor, and look for those two OTC drugs. They're very helpful in preventing the problem. -Emily