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Generic Name: thiopental (THYE oh PEN tal)
Brand Name: Pentothal

What is thiopental?

Thiopental is a barbiturate (bar-BIT-chur-ate). Thiopental slows the activity of your brain and nervous system.

Thiopental is used to help you relax before you receive general anesthesia with an inhaled medication.

Thiopental may be used for other purposes not listed in this medication guide.

What is the most important information I should know about thiopental?

You should not use thiopental if you have porphyria, liver or kidney disease, severe anemia, myasthenia gravis, asthma, a thyroid disorder, or Addison's disease.

What should I discuss with my health care provider before I receive thiopental?

You should not use thiopental if you are allergic to it, or if you have:

  • porphyria (a genetic enzyme disorder that causes symptoms affecting the skin or nervous system);

  • Addison's disease (an adrenal gland disorder);

  • liver or kidney disease;

  • severe anemia (low red blood cells);

  • a thyroid disorder;

  • myasthenia gravis;

  • asthma; or

  • if you are allergic to other barbiturates (amobarbital, butabarbital, mephobarbital, secobarbital, phenobarbital).

To make sure thiopental is safe for you, tell your doctor if you have:

  • severe heart disease;

  • pituitary gland disorder;

  • a pancreas disorder;

  • head injury, brain tumor, or other condition that causes increased pressure inside the skull;

  • problems with the muscles in or around your eyes; or

  • if you take a blood thinner (warfarin, Coumadin, Jantoven).

FDA pregnancy category C. It is not known whether thiopental will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medicine.

Thiopental can pass into breast milk and may harm a nursing baby. Tell your doctor if you are breast-feeding a baby.

How is thiopental given?

Thiopental is injected into a vein through an IV. A healthcare provider will give you this injection.

You will be given this medication while you are lying down. You will fall asleep very quickly after thiopental is injected.

Your breathing, blood pressure, oxygen levels, kidney function, and other vital signs will be watched closely while you are receiving thiopental.

What happens if I miss a dose?

Since thiopental is usually given just for anesthesia, you are not likely to be on a dosing schedule.

What happens if I overdose?

Since this medicine is given by a healthcare professional in a medical setting, an overdose is unlikely to occur.

What should I avoid after receiving thiopental?

Avoid drinking alcohol for at least 24 hours after you leave the hospital or surgery center.

Thiopental can cause severe drowsiness or dizziness, which may last for several hours. You will need someone to drive you home after your surgery or procedure. Do not drive yourself or do anything that requires you to be awake and alert for at least 24 hours.

Thiopental side effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

You will remain under constant supervision during treatment with thiopental. Your caregivers will watch for any serious side effects. Tell your caregivers at once if you have severe pain while receiving this medicine.

Common side effects may include:

  • ongoing drowsiness;

  • weak or shallow breathing;

  • slow heartbeats;

  • chills or shivering;

  • sneezing, coughing, tight feeling in your throat; or

  • bronchospasm (wheezing, chest tightness, trouble breathing).

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect. You may report side effects to FDA at 1-800-FDA-1088.

Thiopental dosing information

Usual Adult Dose for Anesthesia:

When used for induction in balanced anesthesia with a skeletal muscle relaxant and an inhalation agent:
The total dose can be estimated and then injected in two to four fractional doses. With this technique, brief periods of apnea may occur which may require assisted or controlled pulmonary ventilation. As an initial dose, 210 to 280 mg (3 to 4 mg/kg) is usually required for rapid induction in the average adult (70 kg).

When used as the sole anesthetic agent:
Moderately slow induction can usually be accomplished in the "average" adult by injection of 50 to 75 mg (2 to 3 mL of a 2.5% solution) at intervals of 20 to 40 seconds, depending on the reaction of the patient. Once anesthesia is established, additional injections of 25 to 50 mg can be given whenever the patient moves. The desired level of anesthesia can be maintained by injection of small repeated doses as needed or by using a continuous intravenous drip in a 0.2% or 0.4% concentration. With continuous drip, the depth of anesthesia is controlled by adjusting the rate of infusion.

Usual Adult Dose for Seizures:

For the control of convulsive states following anesthesia (inhalation or local) or other causes, 75 to 125 mg (3 to 5 mL of a 2.5% solution) should be given as soon as possible after the convulsion begins. Convulsions following the use of a local anesthetic may require 125 to 250 mg given over a ten minute period.

Usual Adult Dose for Coma Induction:

In neurosurgical patients, intermittent bolus injections of 1.5 to 3.5 mg/kg of body weight may be given to reduce intraoperative elevations of intracranial pressure, if adequate ventilation is provided.

Usual Adult Dose for Psychosis:

For narcoanalysis and narcosynthesis in psychiatric disorders, premedication with an anticholinergic agent may precede administration of thiopental. After a test dose, thiopental is injected at a slow rate of 100 mg/min (4 mL/min of a 2.5% solution) with the patient counting backwards from 100. Shortly after counting becomes confused but before actual sleep is produced, the injection is discontinued. Allow the patient to return to a semidrowsy state where conversation is coherent. Alternatively, thiopental may be administered by rapid IV drip using a 0.2% concentration in 5% dextrose and water. At this concentration, the rate of administration should not exceed 50 mL/min.

Usual Pediatric Dose for Anesthesia:

Induction anesthesia:
less than 1 month: 3 to 4 mg/kg intravenously
less than 1 year: 5 to 8 mg/kg intravenously
1 year to 12 years: 5 to 6 mg/kg intravenously
over 12 years: 3 to 5 mg/kg intravenously

Maintenance anesthesia:
1 year and older: 1 mg/kg intravenously as needed

Usual Pediatric Dose for Seizures:

1 year or older: 2 to 3 mg/kg/dose intravenously, repeat as needed.

Usual Pediatric Dose for Head Injury:

1 year or older: 1.5 to 5 mg/kg/dose intravenously; repeat as needed to control intracranial pressure - larger doses (30 mg/kg) to induce coma after hypoxic-ischemic injury do not appear to improve neurologic outcome.

What other drugs will affect thiopental?

Other drugs may interact with thiopental, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.

See also: Side effects (in more detail)

Where can I get more information?

  • Your doctor or pharmacist can provide more information about thiopental.
  • Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
  • Disclaimer: Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.

Copyright 1996-2012 Cerner Multum, Inc. Version: 2.01.

Date modified: October 13, 2017
Last reviewed: July 30, 2014