What it measures
A check for barbiturates, a group of sedative drugs, or their breakdown products, in a urine sample. Few barbiturates are still prescribed in the UK; phenobarbital, used for epilepsy, is the main one.
Why people test it
- Checked to show no recent use, for example for work, during recovery or for personal reasons.
- Part of wider drug screens that test for several drugs from one urine sample.
Typical range
Reported as detected or not detected (positive or negative) against a cut-off level. Cut-offs vary by lab and the report shows the lab's own; a positive screen is often confirmed by a second, more specific lab method.
Finger-prick or vein?
A urine sample rather than blood, given at a clinic or with a home kit. How long a drug stays detectable depends on the drug, the amount and how often it is used.
Phenobarbital taken on a prescription is detected by this screen in the same way.