Paediatric Laboratory Medicine
Paediatric Laboratory Medicine

Barbiturate and Sedative Screen


Toxicology - Blood Tests - Barbiturate and Sedative Screen

Barbiturates: Amobarbital, Barbital, Butabarbital, Butalbital, Pentobarbital, Pentobarbital, Secobarbital
Sedatives: Glutethimide, Meprobamate, Mathaqualone, Methyprylon

Test Details

Drug Class

Barbiturates & Sedatives

Alternate Name(s)


Acceptable Specimen Type(s)

Plasma (Heparin, Citrate or EDTA)

Minimum Volume

1.0 mL


40 C (transport with a cool pack if possible)

Optimal Collection Time


Special Requirements


Therapeutic Range

Not detected

Critical Value(s)

Included on the interim/final report

Testing Schedule

Daily, Stat

External Proficiency Program(s)




Clinical Significance

The Barbiturates are a large group of structurally similar sedative-hypnotic drugs which are subject to abuse. Screening assays such as this are used to establish the presence or absence of the drug class based on a pre-determined threshold value. Alternative methods must be employed to determine the identity and concentration of any barbiturate from a positive screening result.  Barbiturates are grouped into short-acting and long-acting as follows:

  • Ultra-short acting: Thiopental
  • Short acting: Pentobarbital, Secobarbital
  • Intermediate acting: Amobarbital, Butabarbital, Butalbital 
  • Long acting: Phenobarbital, Barbital

The Sedative-hypnotics are a large group of drugs which cause CNS depression. Most stimulate the activity of Gamma Aminobutyrate (GABA), the principle inhibitory neurotransmitter in the CNS. Similar to the barbiturates the sedatives can be grouped into short-acting and long-acting as follows:

  • Short acting: Methyprylon
  • Intermediate acting: Glutethimide, Meprobamate, Methaqualone

Many of the symptoms seen with barbiturate toxicity are also observed with the sedative-hypnotics. These include: lethargy, coma, hypothermia, slurred speech, irritability, respiratory depression and cardiovascular complications.

Back to Top