Also known as: [Often referred to by brand name]
Formal name: Phenytoin, total and free
Related tests: Therapeutic Drug Monitoring; Emergency and Overdose Drug Testing
Why should I do it?
To determine phenytoin concentration in the blood, to maintain a therapeutic level, and to detect potential for toxicity
When should I do it?
At regular intervals to monitor; as needed to detect low or toxic concentrations
What Kind of Sample is Needed?
A blood sample drawn from a vein in your arm
Test Preparation Needed?