Puff... As Rick said take the "pink stuff", a "slug" each morning. If you eat and drink at the Hotels and bigger restaurants you won't have too much to worry about, but better safe than "sorry meester".
Haven't been to PV but if it is anything like Mazatlan then every store and shop will have a sign "Cuban Cigars". Be vewy, vewy afwaid. You would be better off going to a "reputable" internet site and buying a box of cubans there. As some said even at the "habano house" it will costs $15 to $40 per stick for "cubans". The cigars I mean.
Also, an interesting fact was that the last time we were down there, September, almost all the beach sellers were hustling POT. I have been there 8 times now and had never had any mention of this but the last time it was like "Hey Senor, you need some smoke? I got the good stuff." Or the guys with the jewelry would come up and point to a bracelet or ring with a pot leaf emblem on it and say "You want it, I got it".
Just a "smoking fact".
Anyway have a great time down there and try the sail fishing if you get a chance. A real experience.
Various corn doritos, amigo...69