Monitoring butalbital therapy
Gas Chromatography-Mass Spectrometry (GC-MS)
Axocet
Bucet
Bupap
Butalbital (Fiorinal)
Butalbital, Serum
Cephadyn
Dolgic
Fiorinal (Butalbital)
Phrenilin
Phrenilin (Butalbital)
Phrenilin Forte
Sedapap
Serum Red
Collection Container/Tube: Red top (Serum gel/SST are not acceptable)
Submission Container/Tube: Plastic vial
Specimen Volume: 1.2 mL
Collection Instructions:
1. Draw blood immediately before next scheduled dose.
2. Centrifuge and aliquot serum into a plastic vial within 2 hours of collection.
If not ordering electronically, complete, print, and send a Therapeutics Test Request (T831) with the specimen.
0.6 mL
Gross hemolysis | Reject |
Gross lipemia | OK |
Gross icterus | OK |
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Serum Red | Refrigerated (preferred) | 14 days | |
Ambient | 14 days | ||
Frozen | 14 days |
Monitoring butalbital therapy
Butalbital, short-acting barbiturate with hypnotic properties, is used in combination with other drugs such as acetaminophen, salicylate, caffeine, and codeine.(1)
Butalbital is administered orally. The duration of its hypnotic effect is about 3 to 4 hours. The drug distributes throughout the body, with a volume of distribution of 0.8 L/kg, and about 26% of a dose is bound to plasma proteins. The half-life of butalbital is about 35 to 88 hours. Excretion occurs mainly in the urine.(1,2)
<10 mcg/mL
Butalbital concentrations of 10 mcg/mL or greater have been associated with toxicity.
Specimens collected in serum gel tubes are not acceptable because the drug can absorb on the gel and lead to falsely decreased concentrations.
1. Baselt RC: Disposition of Toxic Drugs and Chemicals in Man. 10th ed. Biomedical Publications; 2014:2211
2. Milone MC, Shaw LM: Therapeutic drugs and their management. In: Rifai N, Horvath AR, Wittwer CT, eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018:800-831
3. Langman LJ, Bechtel LK, Meier BM, Holstege C: Clinical toxicology. In: Rifai N, Horvath AR, Wittwer CT, eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018:832-887
4. Mihic SJ, Mayfield J, Harris RA: Hypnotics and sedatives. In: Brunton LL, Hilal-Dandan R, Knollmann BC, eds. Goodman and Gilman's The Pharmacological Basis of Therapeutics. 13th ed. McGraw-Hill Education; 2017
Barbiturates are extracted from serum using solid-phase extraction techniques. The serum is buffered and eluted with organic solvent. The organic phase is dried, reconstituted, and analysis performed by gas chromatography-mass spectrometry using selected ion monitoring. The assay utilizes deuterated barbiturates as internal standards.(Unpublished Mayo method)
Wednesday
This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.
80345
G0480 (if appropriate)
Test Id | Test Order Name | Order LOINC Value |
---|---|---|
BUTAS | Butalbital, S | 6895-7 |
Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
---|---|---|
8427 | Butalbital, S | 6895-7 |