PLEASE READ!!!! PILLS

ok the thing is i have good job that pays good for the area i live in, about a year ago they started doing random saliva swab test. still i havn;t been tested. even though it has stopped me from smoking it didn;t stop me from growing again this year. everything is looking good so far this year and i already of tons of people who will swap loads of pills for the great smoke that i have grown. i was just wondering if anyone knew of any pain pills that can alter a drug test result, the ones they give are the usual 5 panel test for amp, meth, thc, coke, and opiates. are there any pain pills that can show up as these, i have also heared there are alot of over the counter pills that can alter a test to, if anyone has some info or a link to a site that has the info i am looking for let me know please. thnx