The next time you’re traveling overseas, an important caution when packing your prescription or even over-the-counter medications.

For example, what might seem a harmless allergy drug may be banned in the country where you’re going. Sudafed is banned in Japan and Mexico.

And certain pain relievers that contain codeine are also illegal in the United Arab Emirates, Indonesia, and Greece.

As a precaution, keep your medications in their original containers (no generic pill boxes) and make sure your doctor writes you a letter that explains your condition, and identifies your medications by their brand as well as their generic names.