Test Details
Methodology
Liquid chromatography/tandem mass spectrometry (LC/MS-MS)
Result Turnaround Time
2 - 4 days
Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.
Use
Evaluate toxicity; monitor therapeutic levels
Special Instructions
Co-administration of Lorazepam can potentially cause a falsely lower Clonazepam result in this method.
Limitations
This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.
Footnotes
References
Custom Additional Information
The drug is used in the treatment of petit mal variant (Lennox-Gastaut), akinetic seizures and myoclonic seizures. Serum peak levels occur approximately two hours after oral administration. The apparent half-life after a single oral dose is 20 to 40 hours. Active metabolites have longer half-lives than the parent drug. Half-lives are increased in the elderly. Therapeutic effect is not well correlated with serum levels. Effect of CNS depressants may be augmented by concomitant use of this agent. This drug is used as an anticonvulsant. It is useful in reducing tardive dyskinesia.1
Specimen Requirements
Specimen
Serum or plasma
Volume
4 mL
Minimum Volume
1.1 mL
Container
Red-top tube, lavender-top (EDTA) tube, or green-top (heparin) tube. Do not use a gel-barrier tube. The use of gel-barrier tubes is not recommended due to slow absorption of the drug by the gel. Depending on the specimen volume and storage time, the decrease in drug level due to absorption may be clinically significant.
Collection Instructions
Transfer separated serum or plasma to a plastic transport tube. Collect specimen immediately prior to next dose unless specified otherwise.
Stability Requirements
Temperature | Period |
|---|---|
Room temperature | 14 days |
Refrigerated | 14 days |
Frozen | 14 days |
Reference Range
Therapeutic: 20−70 ng/mL
Storage Instructions
Refrigerate.
Causes for Rejection
Gel-barrier tube
LOINC® Map
| Order Code | Order Code Name | Order Loinc | Result Code | Result Code Name | UofM | Result LOINC |
|---|---|---|---|---|---|---|
| 071712 | Clonazepam (Klonopin(R)),Serum | 3494-2 | 071712 | Clonazepam (Klonopin(R)),Serum | ng/mL | 3494-2 |
| Order Code | 071712 | |||||
| Order Code Name | Clonazepam (Klonopin(R)),Serum | |||||
| Order Loinc | 3494-2 | |||||
| Result Code | 071712 | |||||
| Result Code Name | Clonazepam (Klonopin(R)),Serum | |||||
| UofM | ng/mL | |||||
| Result LOINC | 3494-2 |