Having traveled all over Europe, I tend to disagree with their statement. Often times these things are written by people who have no idea what they're talking about and have never even been to Europe.
It's also very unfair to categorize all countries outside of the U.S. as 'overseas' and then say don't trust any over-the-counter drugs in every country.
In fact, in many occasions, you'll find the products they sell in alot of countries in Europe are better than what we sell in the U.S.
For example, one thing we’ve learned during our travels in Europe, they have some outstanding bath, facial, and hand products that do not include many of the chemicals used in U.S. products. In fact, they have banned over 120 chemicals, which were used in these products, while the U.S. has only banned 10 of them. This was confirmed in an investigative national news report we saw in the U.S. not too long ago, so we always try to buy items like this when traveling overseas.
My wife once got a sinus infection when we were traveling in Europe and she went to the local pharmacist, who gave her some stuff that cleared her right up. It was wonderful. Came back to the U.S. and asked our doctor about it and he said it's great stuff but you can only get it by prescription here and it's alot more expensive. But he said the same thing; often times their products are better than ours, cost less, and contain less banned chemicals that we still use here.
Plus, alot of products we've come accustom to in the U.S. are now sold internationally and are exactly the same as what you find here.
Yes, you want to insure you take more prescription medication than you'll need - that's a no-brainer. But if you want to try and carry all the over-the-counter medications you might need, you'll have to have another whole suitcase! Let's see, if we want to make sure and pack all this stuff, let's not forget medication for diarrhea, nausea, eyes, nose, ears, throat, etc, etc, etc.
Keep in mind, if you're doing a cruise, the ship's store will have alot of this stuff anyway.
And yes, you do need to be careful in some third world countries.
As for medicare or any other health insurance plan, when traveling outside of the U.S. it's always highly suggested purchasing travel insurance through your travel agent as it will cover any out-of-pocket expenses not covered by your regular insurance.
But don't get spooked by articles like this when traveling to the normal tourist destinations in Europe. Their statements are too generalized and not correct for all places.