Yes. Phenobarbital is one of the 76 compounds in the LabX LC-MS/MS confirmation panel, reported as detected at or above 100 ng/mL. The LabX 12-panel screen includes a Barbiturates line designed to pick up Phenobarbital. A screen is presumptive; adding laboratory confirmation identifies Phenobarbital specifically.
Phenobarbital is a long-acting barbiturate and one of the oldest anti-seizure medicines still in use.
Phenobarbital is prescribed for seizure disorders and is used in some hospital protocols.
Phenobarbital is measured by liquid chromatography with tandem mass spectrometry (LC-MS/MS), which separates the compounds in a sample and identifies each one by its mass. That is different from a rapid screen, which reacts to a family of drugs and can occasionally react to a related substance. The laboratory reports Phenobarbital as detected when its concentration is at or above the cut-off of 100 ng/mL, within a reportable range of 100–10,000 ng/mL. It is one of 9 compounds in the muscle relaxants, sedatives and analgesics family on the 76-drug confirmation panel.
The laboratory's confirmation report lists an approximate detection window of 1 day-3 weeks for Phenobarbital. Treat that as a rough guide only: how long any compound stays measurable varies with the amount taken, how often it is used, body composition, metabolism, kidney and liver function, and hydration. A laboratory result cannot be used to work out when a substance was taken.
The LabX 12-panel screen includes a Barbiturates line designed to pick up Phenobarbital. A screen is presumptive; adding laboratory confirmation identifies Phenobarbital specifically.
Phenobarbital is cleared slowly, so it can remain measurable for an extended period. Confirmation distinguishes it from other barbiturates such as butalbital.
Muscle relaxants, barbiturates, nerve-pain medicines and acetaminophen, several of which are monitored in pain management and treatment programs.
Yes. Phenobarbital is one of the 76 compounds in the LabX LC-MS/MS confirmation panel, reported as detected at or above 100 ng/mL. The LabX 12-panel screen includes a Barbiturates line designed to pick up Phenobarbital. A screen is presumptive; adding laboratory confirmation identifies Phenobarbital specifically.
LabX reports Phenobarbital as detected at or above 100 ng/mL, and the method's reportable range is 100–10,000 ng/mL. A result below the cut-off is reported as not detected; it does not prove none was present.
The laboratory lists an approximate window of 1 day-3 weeks, but it varies with dose, frequency of use, metabolism and hydration, and cannot be used to tell when something was taken.
The LabX 12-panel screen includes a Barbiturates line designed to pick up Phenobarbital. A screen is presumptive; adding laboratory confirmation identifies Phenobarbital specifically.
Phenobarbital is prescribed for seizure disorders and is used in some hospital protocols.
Terms on this page: metabolite · cut-off · detection window · presumptive result · confirmation test. More questions: LabX answers.
Test for Phenobarbital and 75 other compounds
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