As long as you have a valid script. it does not where as long as it is from a US MD and a US pharmacy. I do drug testing using the '5 panel' test. it test for PCP, THC, Cocaine, speed and opiates (morphine/ codeine). when it comes back positive several things happen:
First it is tested useing Gas spectromtery. meaning it can differtiate between all types of meds ie hydro vs heroine.
the 5 panel test is extreamly sensitve to chemicals, but can only say + or -. the retest can tell exactly what is causing the + results. if it comes back as ie an antibiotic the MRO will not even call you . if it comes back as a controlled med ie pain meds they will then call the person get info such as what is med, what is number for pharmacy to confirm a script for the med is on file and may even call the patient PMD. if there is a valid script , again from a valid MD there is No problem.

If you have any certin qustions feel free to PM me again I do drug testing/ work in a lab and will answer any questions I can

JOhn