Hello and thank you for your question.
The most common type of employment-related drug screening is a 5-panel test for the following: Marijuana (THC), Cocaine, PCP, Opiates such as codeine and morphine, and Amphetamines, including methamphetamine.
Sometimes a 10-panel test is used, which includes all of the above, but also tests for a variety of other prescription drugs that are legal to possess and use, if precribed.
Employers may also test for alcohol.
Phentermine is chemically similar to Amphetamines, so can potentially cause a positive result in screening tests for Amphetamines.
Usually you will be asked before submitting to the test to list what medications you have recently taken. If your screening shows a positive result for amphetamines, the lab could potentially retest the sample (or a new sample) with additional methods that can confirm the identity of the specific prescription drug (so if you got a positive result, but you'd reported that you are taking phentermine, the lab can confirm that the positive result is indeed due to the presence of phentermine).
You can present a doctor's prescription for the medication to your employer.
Employers cannot discriminate in their hiring practices based on an applicant's use of a prescribed medication for legitimate medical reasons, unless they can clearly establish that use of this medication would inhibit an applicant's ability to perform the job effectively or safely. This type of discrimination is a violation of the Americans with Disabilities Act.
So, no, a positive result should not be a reason that you are not hired, as long as you accurately list this as a medication that you have been prescribed and are currently taking.
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Edited by MJ on 5/30/2010 at 12:50 AM EST