You need to also get some probiotics (opposite of antibiotics) to take. Acidophilus caplets with live, good bacteria, or yogurt, or preferably both. I don't think the yogurt alone is strong enough and it's just easier to pop a caplet than to remember to eat yogurt everyday. Next time you take an antibiotic, start taking acidophilus also. Do not take it at the same time though. If you take it at the same time as the antibiotic, the antibiotic will kill off the good bacteria in the acidophilus. Take this through the whole course of the antibiotics and at least a week afterwards. If you have stomach issues from the antibiotics (diarrhea) it will help with that also. You can also take acidophilus all the time as it is just a good immune system booster.
I also take one teaspoon of garlic juice a day. This is a natural way to kill off yeast in your intestinal tract. I buy it at the grocery store where the spices are sold, or if you are really industrious, you can squeeze your own.
To answer your question about the topical cream, it works because you are growing yeast on your skin, but I agree you need to work on this systemically also so it doesn't come right back.