A
5200 Harry Hines Blvd.
,
Dallas
,
TX
75235
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General Information
Alias: DILANTIN
Performed: 24/7
Turn Around Time: Med Emerg: 2 hours; Routine: 4 hrs
CPT Codes: 80185
Performed By: Chemistry
Clinical Utility:
Monitor therapy, Determine compliance or Assess toxicity.
Toxicity may not correlate well to levels given unpredictable absorption and delayed time to peak. Risk of toxicity can occur at levels >20.0 mcg/mL as follows:
20.0 mcg/mL: Nystagmus
30.0 mcg/mL: Ataxia
40.0 mcg/mL: Decreased mental status
50.0 mcg/mL: Coma
**Notice, risk of toxicity increases in patients with low albumin. If patient has a risk of low albumin (neonates, elderly, uremic, cirrhotic, increased bilirubin), please check Albumin level and calculate Phenytoin (Corrected Phenytoin level = measured level / (0.2 * Albumin) + 0.1). May also check a Free Phenytoin level.
Components
Name |
Method |
Sex |
Age Range |
Ref. Range Low |
Ref. Range High |
Units |
Phenytoin Lvl |
Enzyme Immunoassay |
All |
All |
10 |
20 |
mcg/mL |
Specimen Requirements
Type |
Container |
Volume |
Units |
Collection / Delivery |
Storage / Transport |
Off Campus |
Blood |
Red no Gel, 6mL |
Fill tube |
|
Collect just before next dose. Collect anytime for suspected toxicity but note, toxicity may not correlate well to levels given unpredictable absorption and delayed time to peak. It is recommended to obtain repeated levels for this reason. Deliver to Logistics Lab. |
Room Temperature |
Serum should be separated from cells within 2hrs of collection. Deliver refrigerated serum aliquot to Logistics Lab. |