pack. you've heard of it. your kids have probably been prescribed it. it could trigger an irregular and potentially deadly heart matter. it is prescribed to treat bacterial infections. pneumonia, ear infections that kids get so often. it was prescribed to 40 million americans in 2011, and sales in the last year exceeded $435 million. it's a block-busker drug. dr. manny alvarez is senior managing editor at foxnewshealth.com and a member of the fox news medical a team. surprising news about z pack. >> the news came out last year in 2012, finally the fda looked very carefully at the study and they concluded indeed that for certain groups of peep, especially people who have heart irregularities, low magnesium, low poe tas time, you can get a