Test Code: Phen Preferred Name Phenobarbitone
2 hours (notify lab if required)
|Image||Specimen Type||Specimen Volume||Tube Type|
||Blood (adult)||5 mL||SST 5 mL (Biochem) with GEL (Dark Yellow Top)
||Blood (paediatric)||500 µL||SST with gel 600 uL Paed (Red or Yellow top)
||Blood (neonatal)||500 µL||SST with gel 600 uL Paed (Red or Yellow top)
Collect just prior to next dose. Please note the dosage and dose time on the request slip to allow interpretation of results.
APPLICATION: Therapeutic drug monitoring of phenobarbitone or primidone.
INTERPRETATION: Phenobarbitone has a long half-life and a steady state may not be reached for several weeks. Mean half-life is 100 hours. Primidone is metabolised to phenobarbitone.
For advice on collection times, contact the Therapeutic Advisory Service (beep 0282).