Lab Dept:

Chemistry

Test Name:

CLONAZEPAM LEVEL

General Information

Lab Order Codes:

CLZ

Synonyms:

Klonopin®; Clonopin, Nitrozepane; Rivotrol

CPT Codes:

80346 – Benzodiazepines; 1-2 OR
G0480 – Drug, test, definitive (if appropriate)

Test Includes:

Clonazepam level reported in ng/mL.

Logistics

Test Indications:

Clonazepam is a long-acting benzodiazepine restricted in use to those patients who have responded for seizure control only to diazepam, but who no longer respond to diazepam within non-toxic levels. Clonezepam is an effective anticonvulsant, but used only as a last resort because of its side effects.

Lab Testing Sections:

Chemistry - Sendouts

Referred to:

Mayo Medical Laboratories (MML Test: CZPS)

Phone Numbers:

MIN Lab: 612-813-6280

STP Lab: 651-220-6550

Test Availability:

Daily, 24 hours

Turnaround Time:

2-6 days, performed Tuesday and Thursday

Special Instructions:

Should be drawn at trough or immediately before next dose.
Levels may be elevated in none-trough specims

Specimen

Specimen Type:

Blood

Container:

Red top tube, NO GEL

Draw Volume:

3.6 mL (Minimum: 1.8 mL) blood

Processed Volume:

1.2 mL (Minimum: 0.6 mL) serum

Collection:

Routine venipuncture

 

Special Processing:

Lab Staff: Centrifuge specimen, remove serum aliquot into a screw-capped round bottom plastic vial. Store and ship at refrigerated temperatures. Forward promptly.

Patient Preparation:

None

Sample Rejection:

Mislabeled or unlabeled specimens; collected in gel tube

Interpretive

Reference Range:

Anticonvulsant: 20 – 70 ng/mL
Anxiolytic: 4 – 80 ng/mL

Note: Some individuals may show therapeutic reponse outside these ranges, or may display toxicity within the therapeutic range, thus interpretation should include clinical evaluation. Levels may be elevated in non-trough specimens.

Critical Values:

N/A

Limitations:

N/A

Methodology:

Liquid Chromatography-Tandem Mass Spectromety (LC-MS/MS)

References:

Mayo Medical Laboratories June 2016

Updates:

3/1/2004: Test moved from MedTox Laboratories to Mayo Medical Laboratories. Note: change in reference range from 20-60 ng/mL to 10-50 ng/mL.
4/22/2010: MML made test 8385 obsolete and started referring test 500108 to MML New England. Note updated ref range and method.
3/18/2014: Draw volume and minimum increase per MML.
2/2/2016: CPT update
6/8/2016: Method update per MML.