Mephenytoin and Normephenytoin

Abbrev Code:XMISC   
Order Code:LAB4909Order Name:Mephenytoin and Normephenytoin
Synonyms:Mesantoin; Nirvanol
Methodology:High performance liquid chromatography with ultraviolet detection
CPT Codes: 80185 x2
Test Includes:Mephenytoin and Nirvanol (metabolite)
Turnaround Time:Specimens are sent to reference laboratory Mon-Fri; results are reported within 3 days.

This test was developed and its performance characteristics determined by LabCorp. It has not been cleared or approved by the Food and Drug Administration.

Collection Instructions

Optimal Volume:4 mL
Minimum\Peds Volume:1.4 mL
Container:Red (no gel)
Alternate Containers: Green (lithium heparin, no gel), Green (sodium heparin, no gel)
Collection Instructions:Usual sampling time is immediately prior to next dose (trough).
Contraindications:Use is contraindicated in patients who have shown a previous hypersensitivity to hydantoin products.

Processing and Shipping

Specimen Processing:Centrifuge and aliquot 2 mL, 0.6 mL minimum. Store at room temperature.
Shipping Instructions:Ship at room temperature.
Test Performed at or Referral Lab Lab Sendouts  (MedTox)
Referral Lab number:68


Critical Range:Mephenytoin: 20 ug/mL or greater
Reference Range:Mephenytoin: 1-5 ug/mL; Normephenytoin: 15-35 ug/mL.
Use:Therapeutic monitoring and assess toxicity.

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