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HelpTest Code DILN Phenytoin (Dilantin) Level
Additional Codes
| EPIC | LAB4161 |
Synonyms
- Diphenylhydantoin
Clinical Significance
Phenytoin (diphenylhydantoin) has been used extensively for seizure control in patients having both grand mal epilepsy (major motor), cortical focal seizures, and temporal lobe epilepsy. Serum level monitoring of the drug is essential in order to achieve maximal seizure control while maintaining minimal blood levels. Because of individual variation in absorption and metabolism, optimum levels may vary.
Source: Roche Cobas PHNY3 Method Sheet Version 5.0 2022-09
Methodology
Kinetic interaction of microparticles (KIMS) (Roche Cobas c503)
Sample Type
| Preferred Sample Type | |
|---|---|
| Light green top - Plasma | |
| Acceptable Sample Types | |
|---|---|
| Dark green top - Plasma | |
| Yellow top - Serum | |
| Red top - Serum | |
Centrifuge: Yes
Specimen Minimum Volume
55 uL with insert cup
Specimen Stability
| Temperature | Time |
|---|---|
| Ambient air (15-25°C) | 4 days |
| Refrigerated (2-8°C) (store) | 4 days |
| Frozen (-20°C) | 2 months* |
Separate plasma or serum from cells within 2 hours.
*Freeze only once! Do not freeze heparanized plasma samples!
Reference Ranges
| Therapeutic Range |
|---|
| 10 - 20 ug/mL |
| Critical Value |
|---|
| >20 ug/mL |
| Technical Range |
|---|
| 0.8 - 40.0 ug/mL |
Rejection Criteria
| Hemolysis | Index >1,000 |
|---|---|
| Icterus | Index >50 |
| Lipemia | Index >800, ultracentrifuge* |
Availability
| Performed | STAT |
|---|---|
| 24/7 | Yes |
Performing Laboratory
MultiCare Yakima Memorial Hospital Laboratory
Lab Department
Chemistry
CPT Code
80185
LOINC
3968-5 Phenytoin [Mass/Vol]