If the meds are prescribed it won't be a problem as long as the quantities aren't excessive, but the customs officer will want to see the prescription so you better have it with you. Should they choose the latter, I'd suggest having a very good story ready. They cater exclusively to US citizens coming across the border. They tend to focus on the expensive popular drugs, i.e. Viagra, Prozac, Propecia, etc. There are hundreds of these pharmacies scattered around.
Some pharmacists speak fluent English, others almost none.
Practice in a couple of pharmacies and see how low you can get the price before they refuse. Don't be afraid to suggest prices, or to walk out and go somewhere else. Figuring out differences between brand names and drug names is tough enough in English with a doctor that you trust. Trying to do it in a foreign language, with someone of uncertain qualifications who may be eager to make a sale is much harder. Because I had prescriptions for the all the medications I was interested in buying, my evaluations were based primarily on cost.