Phentermine drug testBe advised that if your employer requires periodic drug testing, having Phentermine in your system . testing of the urine will determine if these interfering drugs are present. . A drug test is a technical analysis of a biological specimen — for example urine, hair, blood, sweat, or oral fluid / saliva — to determine the presence or absence of . . . . . . . . Best Answer: i took some norcos 5 days prior to a surprised saliva drug test please someone tell me im go... more