Phenobarbital, known by the brand names Nembutal, Luminal, and others, is a barbiturate drug. Barbiturates are central nervous system depressants that were originally designed to treat anxiety, anxiety disorders, and seizures. Their list of potential medicinal uses also includes assisting with the treatment of insomnia, acting as a preanesthetic drug to relax individuals before anesthesia is administered, and assisting in withdrawal from alcohol and even other benzodiazepines. They are also used as muscle relaxants and as lethal injection drugs in prisons.
The United States Drug Enforcement Administration classifies phenobarbital as a Schedule IV controlled substance. Drugs in this class have a moderate potential for abuse and can result in the development of physical dependence if taken for lengthy periods of time. Except for the control of seizures, phenobarbital is not typically prescribed for long periods of time. Its use as an anti-anxiety medication has declined significantly since the development of benzodiazepines. Even when phenobarbital is used as an anti-anxiety medication, it is considered to be a short-term solution that can help an individual while behavioral interventions are delivered.
Using phenobarbital as a withdrawal management medication or sleep aid would also be considered a short-term process due to individuals developing tolerance to phenobarbital rapidly; its initial medicinal effects also wear off rapidly.
According to the Substance Abuse and Mental Health Services Administration (SAMHSA), barbiturates like phenobarbital are not as commonly used as they once were. They are more likely to be prescribed to elderly individuals as sleep aids or to treat anxiety. Phenobarbital is still useful in the control of seizures, and individuals who use phenobarbital for this purpose often use it for lengthy periods of time. Much of the data describing the long-term effects of phenobarbital use come from animal research studies and observational studies in individuals with epilepsy or other seizure disorders who took the drug for lengthy periods.