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Phenobarbital, plasma or serum

Lab area
Clinical Biochemistry - TDM & Toxicology
Method and equipment
Abbott Architect ci-4100
Expected turn-around time
Stat/ Urgent / Routine: 2 hours
Specimen type

Serum, Plasma (Heparin or Citrate)

Specimen requirements

150 uL

Storage and transportation

4°C (transport with a cool pack if possible)

Shipping information
The Hospital for Sick Children
Rapid Response Laboratory
555 University Avenue, Room 3642
Toronto, ON
M5G 1X8
Phone: 416-813-7200
Toll Free: 1-855-381-3212
Hours: 7 days/week, 24 hours/day
Background and clinical significance
Phenobarbital is the most effective barbiturate in long-term treatment of seizure disorders. Strong correlation has been observed between serum levels and both therapeutic and toxic effects. Phenobarbital is excreted, partly metabolized and partly unchanged, very slowly through the urine. Both metabolism and clearance are highly variable among individuals; therefore, close monitoring of serum levels is essential for every patient undergoing phenobarbital therapy. Clinical observations indicate that toxicity of phenobarbital is increased in patients with renal disease. Phenobarbital toxicity primarily affects the central nervous system. Some patients on long term therapy may develop macrocytosis, megaloblastic anemia and osteomalacia.
Disease condition


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