Sign in →

Test ID FBCFS Barbiturates Confirmation, Serum

Specimen Required

Only orderable as a reflex test.

Method Name

Gas Chromatography/Mass Spectrometry (GC/MS)


Only orderable as a reflex test.

Reporting Name

Barbiturates Confirmation, S

Specimen Type

Serum Red

Specimen Stability Information

Specimen Type Temperature Time Special Container
Serum Red Refrigerated (preferred) 14 days
  Frozen  30 days

Reference Values

Reporting limit determined each analysis.






None Detected


Plasma concentrations of 2-3 mcg/mL produce sedation and plasma concentrations of 25 mcg/mL produce sleep in most patients. Plasma concentrations of greater than 30 mcg/mL may produce coma and plasma concentrations in excess of 50 mcg/mL are potentially lethal.



None Detected


A single oral 100 mcg dose resulted in a mean peak blood concentration of 2.1 mcg/mL (range, 1.7-2.6 mcg/mL) at 2 hours, with a decline to 1.5 mcg/mL (range, 1.3-1.7 mcg/mL) by 24 hours. Potentially toxic at plasma concentrations greater than 10 mcg/mL.



None Detected


Peak serum concentrations of 1.2-3.1 mcg/mL were produced 0.5-2.0 hours after a 100 mg oral dose and peak serum concentration of 3 mcg/mL were produced 6 min. following a 100 mg IV dose. Potentially toxic at blood concentrations greater than 10 mcg/mL.



None Detected


A 3.3 mg/kg oral dose (approx. 230 mg/70 kg) produced a mean peak blood concentration of 2.0 mcg/mL (range, 1.8-2.2 mcg/mL) at 3 hours, diminishing to 1.3 mcg/mL by 20 hours and 0.8 mcg/mL by 40 hours. Potentially toxic at blood concentrations greater than 8 mcg/mL.



None Detected


Recommended serum concentration range during anticonvulsant therapy with primidone: 10-40 mcg/mL.

Performing Laboratory

NMS Labs

CPT Code Information


G0480 (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
FBCFS Barbiturates Confirmation, S Not Provided


Result ID Test Result Name Result LOINC Value
Z5287 Butabarbital 18384-8
Z5288 Butalbital 82971-3
Z5290 Pentobarbital 82969-7
Z5291 Secobarbital 82968-9
Z5292 Phenobarbital 60468-6