Barbiturate class

Clinical details: Barbiturates are a group of drugs with properties that range from sedative to hypnotic to anti-convulsant. Barbiturates can be classified according to their duration of action. Some short acting barbiturates, such as hexobarbital, have a half life of only 3-7 hours, while longer acting barbiturates have half lives of 30-40 hours (butobarbital) or as much as 90-100 hours (phenobarbital). Phenobarbital in particular has been used to â€˜cut' heroin, and unknown barbiturate addiction can present added complications to a patient in rehabilitation and detoxification. Barbiturates are rarely encountered in current drugs of abuse testing, though our immunoassay is available on request to detect use of the most common barbiturates.

Reference range: (cut-off) 300 µg/L

UDS service information leaflet

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Sample type and volume required: Random urine sample (10-20 mL) collected into a plain 30 mL universal container. Please ensure containers are tightly sealed, and are sent in a clear plastic bag separate from the accompanying request form. Please also ensure containers are labelled with the full name and date of birth of the client, and the specimen collection date and time.

Special sample instructions: Additional specialist tests by enzymatic assay (urine ethanol), and by LC-HR-MS (buprenorphine and metabolites, ketamine and norketamine, mephedrone, tramadol and metabolites - see other analytes in the ‘Our Tests’ section of the website) are available on request, and can be carried out on the same specimen as supplied originally.

Storage and transport: Please refrigerate (if possible) if not sending immediately. Send by first class post.

Last updated: 19 June 2026