Benzodiazepine , Quantitative, Serum or Plasma Mnemonic BENZ S Synonym Alprazolam (Xanax) - Lorazepam (Ativan) - Nordiazepam, Oxazepam (Serax) - Temazepam (Restoril) - Diazepam (Valium) Includes Lorazepam, Nordiazepam, Oxazepam, Temazepam, Alprazolam, Diazepam Specimen Collection Requirements Collect Serum or Plasma, one 7.0 mL red, 4.0 mL dark green (sodium heparin), or 4.0 mL lavender (EDTA) top tube. SST and PST tubes are NOT recommended. Handling Allow serum to clot completely at room temperature (minimum 30 minutes). Centrifuge and separate serum or plasma from cells ASAP. Preferred Volume 2 mL Serum or Plasma Minimum Volume 0.50 mL Serum or Plasma (Whole Blood draw 1.50 mL) Transport Refrigerated (2-8°C) Rejection Criteria Frozen whole blood, gross hemolysis, specimens collected in PST or SST tubes that were not removed from the gel separator within 24 hours Stability Ambient (20-25°C): 2 weeks; Refrigerated (2-8°C): 2 months; Frozen (at or below -20°C): 2 months Testing Information Performed Tue, Thu Reported 1-5 days Method Liquid Chromatography Tandem Mass Spectrometry Reference Values Reference Values Diazepam, Nordiazepam, Oxazepam, Temazepam, Lorazepam, Alpha Hydroxy Alprazolam: Not Detected < 20 ng/mL Alprazolam: Not Detected < 2 ng/mL Therapeutic Range For Therapeutic Ranges, please refer to Therapeutic Drug Monitoring (TDM) Guidelines for Pediatrics and Adults Toxic Levels For Toxic Ranges, please refer to Therapeutic Drug Monitoring (TDM) Guidelines for Pediatrics and Adults Comments Identification of specific drug provided. CPT Codes 80346, G0480 Last Updated: Saturday, December 12, 2020 02:31:00 AM Client Services: 503-413-1234