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HelpTest Code PHYT Dilantin Level
Additional Codes
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Cerner |
NextGen |
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Dilantin Level |
Dilantin Level |
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Phenytoin Level |
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Alternate Name(s)
Phenytoin Level
Useful For
Phenytoin (Dilantin) is a widely prescribed anticonvulsant drug used in the treatment of generalized and partial seizures. Phenytoin measurements are used to monitor patient compliance and therapy and to diagnose potential overdose.
Methodology
Enzymatic Heterogenous CIA, Multiple-point immuno-rate
Patient Preparation
None
Collection Instructions
- Standard phlebotomy practices.
- Specimen collection times:
- Monitor long term therapy – just before next dose.
- Adequate therapy - just before next dose.
- Possible toxicity – 6 hours after last dose or up to 8 hours if drug is given with substances that increase stomach acidity.
Specimen Requirements
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Container |
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Stability |
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Rejection Criteria |
Gross Hemolysis |
Result Reporting and Reference Values
Reported in µg/mL
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Age |
Low |
High |
Critical Low |
Critical High |
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Therapeutic Range |
10.0 |
20.0 |
N/A |
>30.0 |
Reflex Testing
None
Limitations
- Ortho reports a bias with the following:
- Total Protein >9.0 g/dL have been shown to cause a bias >2.3 µg/mL
- Bilirubin (Bc) at 20 mg/dL has been shown to cause bias of +7.8 µg/mL
- Ethamsylate 3.0 mg/dL has been shown to cause a bias of +7.1 µg/mL
- Gentisic acid at 5.00 mg/dL has been shown to cause a bias of 9.6 µg/mL
- Hemoglobin at 200 mg/dL has been shown to cause a bias -5.9 µg/mL
- Ortho reports no significant effect with the following:
- Lipemia up to 800 mg/dL
- The following interpretive data is visible to pracitioner:
- Total protein >9.0 g/dl may give a positive bias. The following drugs at therapeutic levels may interfere with phenytoin determination creating a positive bias; Ethamsylate, Gentisic acid, Hypaque, N-acetylcysteine