I will be submitting a urine specimen for a drug screen in several days. I currently take Sustiva, which is known to sometimes cause false positives for cannabinoids. While the specimen is going to a major reference lab for testing, I do not know the how the sample will be processed (EMIT, GC/MS). If I put sustiva on the list of prescriptions I am currently taking, will this be reported to my employer. I am not worried about my status at the collection facility, as it is the same one I have my HIV labs collected.

The testing agency should not be reporting meds to your employer for this screen. YOu are correct to be concerned about which assay they use, though. Rather than naming the medication, why not just tell them that, for an accurate result, your pharmacist has told you that your sample needs to be tested using the GC/MS test? Ask them to verify that they'll use that assay, and you'll protect your information and be able to relax.

Your status at the collection facility is a confidential matter. Such agencies are subject to huge suits and fines if they disclose results to anyone other than the treating physician or the patient.