What Is A Lethal Dose Of Phenobarbital (Luminal)?

Phenobarbital (Luminal) is an anti-seizure drug that belongs to a class of medications known as barbiturates. It is rarely prescribed, due to a risk of toxicity and overdose. Phenobarbital may be prescribed as phenobarbital, Luminal, Barbital, and Solfoton.

Phenobarbital comes in the form of a liquid or tablet for use one to three times a day. Taking phenobarbital in any way other than prescribed can risk serious side effects, including overdose.

Learn more about the lethal dose of commonly abused drugs

How A Lethal Dose Of Phenobarbital Is Determined

The lethal dose of phenobarbital is between six to 10 grams, or 6,000 to 10,000 milligrams (mg). For comparison, phenobarbital is generally prescribed in doses of 30–320 mg daily, depending on the intended use.

Taking a higher dose of phenobarbital than prescribed, or mixing it with other drugs, can lead to toxicity, or overdose. Severe cases of overdose can be fatal.

Risk Factors For Fatal Phenobarbital Overdose

Phenobarbital overdose can be more dangerous for people who have certain medical conditions or circumstances that affect how their body processes the medication. Knowing these risk factors is important for people and healthcare providers to ensure safe use of this medication.

Risk factors for fatal phenobarbital overdose include:

• Older Age: elderly patients process medications more slowly and may be more sensitive to barbiturates’ effects on breathing and heart function
• Use of Multiple Drugs: taking other medications, especially those that affect the central nervous system, can amplify phenobarbital’s effects
• Alcohol Use: alcohol is a depressant that significantly increases the risk of respiratory depression when combined with phenobarbital
• Taking Multiple Doses Over a Short Period of Time: this can lead to accumulation of the drug in the body before previous doses have been fully processed
• Impaired Kidney or Liver Function: these organs are responsible for processing and eliminating the drug from the body; when they don’t work properly, the medication can build up to toxic levels
• Low Body Weight: smaller individuals may be more susceptible to overdose at lower doses than larger people

Phenobarbital overdose is a serious medical emergency that requires immediate professional medical attention. If someone is experiencing symptoms of overdose or taking this medication inappropriately, it’s important to get help.

Recognizing Signs Of A Phenobarbital (Luminal) Overdose

Phenobarbital overdose can be life-threatening without prompt medical treatment. If someone you know is experiencing signs of overdose, seek medical attention right away.

Signs of a phenobarbital overdose can include:

• low blood pressure
• difficulty breathing
• slowed or no breathing
• sleepiness
• slurred speech
• weak pulse
• confusion
• large blisters
• skin rash
• headache
• poor balance

Severe symptoms of overdose can include heart failure, kidney failure, and coma. Treatment for overdose may involve activated charcoal, a stomach pump, IV fluids, and airway support.

Treatment For Phenobarbital Abuse

Taking phenobarbital (Luminal) in higher doses than prescribed or using it without a medical need are signs of drug abuse and potential addiction. While phenobarbital has legitimate medical uses for treating seizures and other conditions, it can be habit-forming when misused. People who develop dependence on phenobarbital may experience withdrawal when they try to stop.

The good news is that recovery from phenobarbital addiction is possible with the right treatment and support. Treatment options typically include medically supervised detox to manage withdrawal symptoms, counseling and therapy, support groups, and ongoing medical care to monitor health and prevent relapse. If you or someone you know is battling phenobarbital abuse, it’s important to seek help from professionals who specialize in addiction treatment.

Written by the Addiction Resource Editorial Staff