Phenytoin

For Specimen Integrity during Extreme Weather see the “Lockbox Usage in Extreme Weather” document at the top of this page.

Generally collected 6 - 8 hrs post drug administration

DIL

713;
Dilantin;
Dilantin Level;
Diphenylhydantoin;
Hydantoin;

serum

0.5 mL

plasma from Lithium Heparin (Light Green Top) tube

Barrier tubes (serum separator tubes or plasma separator tubes) are preferred. If non-barrier tubes are utilized, the serum/plasma must be removed immediately after centrifuging and placed in a screw-cap transfer tube.

Collection notes: Avoid hemolysis. Invert tubes at least 8 times. Allow to clot in an upright position for 30 minutes. Within 2 hours, centrifuge tubes 10 minutes. Keep tightly stoppered.

Do NOT re-centrifuge tubes. Do NOT freeze the primary collection tube.

TRANSFER TO SCREW-TOP TRANSPORT TUBE.

Screw-top plastic transport tube

Room Temperature or Refrigerated

Room Temperature = 4 days
Refrigerated = 4 days
Frozen = 2 months

Hemolysis, Lipemia, incorrect specimen type, insufficient sample volume, improper storage conditions, exceeds specimen stability guidelines, contaminated sample.

DAILY
AU

daily

Phenytoin is an anticonvulsant hydantoin used for the treatment of generalized tonic-clonic (grand mal) and complex partial seizures. Phenytoin is also used for prophylaxis in neurosurgical procedures. Phenytoin levels are monitored to assure adequate therapeutic levels are achieved and to avoid toxicity.