URL of this page: //www.nlm.nih.gov/medlineplus/ency/article/002530.htm

Phenobarbital overdose

Phenobarbital is a medicine used to treat epilepsy, anxiety, and insomnia. Phenobarbital overdose occurs when someone takes too much of this medicine.

This is for information only and not for use in the treatment or management of an actual poison exposure. If you have an exposure, you should call your local emergency number (such as 911) or the Poison Control Center at 1-800-222-1222.

Poisonous Ingredient


Where Found

Other names for this drug are:

  • Barbita
  • Comizial
  • Gardenale
  • Fenilcal
  • Luminal
  • Solfoton

Note: This list may not be all-inclusive.


Heart and blood vessels:

  • Heart failure
  • Low blood pressure
  • Weak pulse

Kidneys and bladder:

  • Kidney failure (possible)


Nervous system:

  • Coma
  • Confusion
  • Decreased energy
  • Delirium (confusion and agitation)
  • Headache
  • Sleepiness
  • Slurred speech
  • Unsteady gait


Before Calling Emergency

The following information is helpful for emergency assistance:

  • The person's age, weight, and condition
  • Name of product (as well as the ingredients and strength if known)
  • The time it was swallowed
  • The amount swallowed
  • If the medicine was prescribed for the person

However, DO NOT delay calling for help if this information is not immediately available.

Poison Control

In the United States, call 1-800-222-1222 to speak with a local poison control center. This hotline number will let you talk to experts in poisoning. They will give you further instructions.

This is a free and confidential service. All local poison control centers in the United States use this national number. You should call if you have any questions about poisoning or poison prevention. It does NOT need to be an emergency. You can call for any reason, 24 hours a day, 7 days a week.

Take the pill container with you to the hospital, if possible.

What to Expect at the Emergency Room

The health care provider will measure and monitor the person's vital signs, including temperature, pulse, breathing rate, and blood pressure. Blood tests will be done to check the phenobarbital level.

Symptoms will be treated as appropriate. The person may receive:

  • Activated charcoal
  • Airway support, including oxygen, breathing tube through the mouth (intubation),and ventilator (breathing machine)
  • Blood and urine tests
  • Chest x-ray
  • EKG (electrocardiogram, or heart tracing)
  • Fluids through the vein (intravenous or IV)
  • Laxative
  • Medicines to treat symptoms

This list may not be all-inclusive.

Outlook (Prognosis)

How well the person does depends on the severity of the overdose and how quickly treatment is received. If there has been prolonged coma and shock (damage to multiple internal organs), a more serious outcome is possible.

Alternative Names

Luminal overdose


Goldfrank LR, ed. Goldfrank's Toxicologic Emergencies. 9th ed. New York, NY: McGraw Hill; 2011.

Gussow L, Carlson, A.Sedative Hypnotics. In: Marx JA, Hockberger RS, Walls RM, et al., eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. 8th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 165.

Update Date 1/17/2015