Maybe I am just "lucky", but I have NEVER had anyone go thru any medications entering any country, and travel fairly frequently. If IOP order usually "hide" whatever at the bottom of a bottle of laxative pills - what customs agent is going to go thru a bottle of laxatives...

As for seizure letter and further scrutiny when entering the country - I highly doubt it - usually the right and left hand don't even know they are on the same body.