If the requirements of your probation are that you successfully pass a 4-panel drug test, you won't be violating probation. As you said, alprazolam (benzodiazepines in general, in fact) are NOT tested (in THAT test, anyway), so even if they were found, you are not in violation unless the terms of your probation specifically prohibit those medications.
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If the requirements of your probation are that you successfully pass a 4-panel drug test, you won't be violating probation. As you said, alprazolam (benzodiazepines in general, in fact) are NOT tested (in THAT test, anyway), so even if they were found, you are not in violation unless the terms of your probation specifically prohibit those medications.