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What is pentobarbital?
Pentobarbital is in a class of drugs called barbiturates (bar bi TURE ates). Pentobarbital depresses the activity of your brain and nervous system. Pentobarbital is used to treat insomnia (for up to 2 weeks) and to induce sleep before surgery. Pentobarbital may also be used for purposes other than those listed in this medication guide.

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What are the possible side effects of pentobarbital?

If you experience any of the following serious side effects, stop taking pentobarbital and seek emergency medical attention or call your doctor immediately:

• an allergic reaction (difficulty breathing; closing of your throat; swelling of your lips, tongue, or face; or hives);

• a fever or a sore throat;

• sores in your mouth;

• broken blood vessels under your skin; or

• easy bruising or bleeding.

Other, less serious side effects may be more likely to occur. Continue to take pentobarbital and talk to your doctor if you experience

• drowsiness or dizziness;

• confusion;

• agitation, irritability, or excitability;

• nightmares, nervousness, or anxiety;

• headache; or

• "hangover" effect (drowsiness the day after a dose).

Pentobarbital is habit forming, which means that you can become addicted to it. Your doctor will want to monitor how much medicine you are taking. Your dosage may have to be reduced slowly to prevent withdrawal effects.

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.

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How should I take pentobarbital?
Take pentobarbital exactly as directed by your doctor. If you do not understand the directions on your prescription bottle, ask your pharmacist, nurse, or doctor to explain them to you. Take each dose with a full glass of water. The suppositories are for rectal use. Ask your pharmacist, nurse, or doctor for instructions if you do not know how to insert a suppository. To treat insomnia, pentobarbital is usually taken just before bedtime. Take your dose when you are ready to get into bed, or not long before, so that if you become sleepy, you will not fall or become confused and accidentally injure yourself. Pentobarbital should not be used for longer than 2 weeks to treat insomnia.

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What is the most important information I should know about pentobarbital?
Call your doctor immediately if you develop a fever, a sore throat, sores in your mouth, broken blood vessels under your skin, or easy bruising or bleeding. These could be early signs of a serious side effect. Use caution when driving, operating machinery, or performing other hazardous activities. Pentobarbital will cause drowsiness. If you experience drowsiness, avoid these activities. Do not drink alcohol or take other sleep medicines, antihistamines, narcotic pain relievers, or other drugs that also cause drowsiness unless your doctor approves. Dangerous sedation could result.

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What happens if I miss a dose?
Take the missed dose as soon as you remember. However, if it is almost time for your next regularly scheduled dose, skip the missed dose and take the next one as directed. Do not take a double dose of this medication.

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What other drugs will affect pentobarbital?
Large chronic doses of pentobarbital may cause liver damage if it is taken with acetaminophen (Tylenol, others). Tell your doctor and pharmacist if you are taking pentobarbital on a regular basis. Pain and fever reducers other than acetaminophen are available and may be more suitable choices. Pentobarbital may decrease the effectiveness of many drugs, including the following: blood thinners such as warfarin (Coumadin). Blood clotting could result. carbamazepine (Tegretol) and clonazepam (Klonopin). Reduced effectiveness of these medicines could lead to poor seizure control.

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Can I take this if I am pregnant or trying to get pregnant or if I am breastfeeding?

Pentobarbital has been assigned to pregnancy category D by the FDA. An increased risk of congenital malformations has been associated with use of other barbiturates (including phenobarbital) and anticonvulsants during pregnancy. Pentobarbital has not been specifically implicated, but may pose similar risks. Defects associated with anticonvulsant use in pregnancy include neural tube defects, cleft lips, cleft palates, cardiac defects, and microcephaly. Neonatal barbiturate withdrawal symptoms have also been reported in infants whose mothers took barbiturates during pregnancy. There are no controlled data in human pregnancy. Pentobarbital should only be given during pregnancy when there are no alternatives and benefit outweighs risk.

Pentobarbital is excreted into human milk in small amounts. The possibility of accumulation of other barbiturates in nursing infants has been reported, although pentobarbital has not been specifically implicated. The American Academy of Pediatrics has no formal position on pentobarbital but classifies phenobarbital as a drug which has "caused significant effects on some nursing infants and should be given to nursing mothers with caution."

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What does my medication look like?
Pentobarbital is available with a prescription generically and under the brand name Nembutal in capsules, suppositories, and as an injection. Other brand or generic formulations may also be available. Ask your pharmacist any questions you have about this medication, especially if it is new to you. Nembutal Sodium 50 mg--orange-and-clear capsules Nembutal Sodium 100 mg--yellow capsules Nembutal Sodium Suppositories in 30 mg, 60 mg, 120 mg, and 200 mg strengths

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What happens if I overdose?
Seek emergency medical attention. Symptoms of a pentobarbital overdose include difficulty breathing, back-and-forth movements of the eyes, appearance of being drunk, fast heartbeat, low body temperature, heavy sedation, coma, and death.

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Who should not take pentobarbital?
Do not take pentobarbital if you have porphyria, liver disease, kidney disease, or severe respiratory disease such as severe asthma or severe chronic obstructive pulmonary disorder (COPD). Before taking this medication, tell your doctor if you have ever had a drug or alcohol addiction in the past. Pentobarbital is habit forming, which means that you can become addicted to it. Pentobarbital is in the FDA pregnancy category D. This means that it is known to harm an unborn baby. Do not take pentobarbital if you are pregnant.

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Can I stop taking the medication if I feel better?
As a general rule, you should always take your medications exactly as prescribed and do not change the dosage or stop taking the medication without first discussing it with your healthcare provider.

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I am on so many medications; do I have to take them all?
This is called polypharmacy—many different medications being used at the same time by one person. Sometimes, being on multiple medications is acceptable and appropriate but at other times it may be problematic. If you are receiving your medications from multiple physicians you need to ensure that they all know what medications you are taking. The best way to do this is to make a list of all the medications you are currently using, including all nutritional supplements, homeopathic remedies, vitamins and over-the-counter drugs (if possible, also include all the diseases you have been diagnosed with). Give a copy to every doctor who takes care of you so they have it on file, this way they can avoid duplicating medications and perhaps even try to consolidate some. After every doctor's visit remember to update the list accordingly. Also, as much as you possibly can, try to use the same pharmacy to fill all your prescriptions, this way any potential drug interactions can be caught and averted.

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