Phenobarbital

Pronunciation: fee-noe-BAR-bi-tal
Generic Name: Phenobarbital
Brand Name: Luminal

Phenobarbital is used for:

The short-term treatment of sleeplessness, the relief of anxiety, tension, and fear, and the treatment of certain types of seizures, especially in emergency situations. It may also be used for other conditions as determined by your doctor.

Phenobarbital is a barbiturate. It works by depressing the central nervous system. This aids you in relaxing and going to sleep.

Do NOT use Phenobarbital if:

• you are allergic to any ingredient in Phenobarbital


• you have the blood disorder porphyria


• you are also taking sodium oxybate (GHB)

Contact your doctor or health care provider right away if any of these apply to you.

Before using Phenobarbital:

Some medical conditions may interact with Phenobarbital. Tell your doctor or pharmacist if you have any medical conditions, especially if any of the following apply to you:

• if you are pregnant, planning to become pregnant, or are breast-feeding


• if you are taking any prescription or nonprescription medicine, herbal preparation, or dietary supplement


• if you have allergies to medicines, foods, or other substances


• if you suffer from depression, have suicidal tendencies, have a history of substance abuse


• if you have liver problems or respiratory disease


• if you have pain or are in shock

Some MEDICINES MAY INTERACT with Phenobarbital. Tell your health care provider if you are taking any other medicines, especially any of the following:

• Sodium oxybate (GHB), stiripentol, or valproic acid because they may increase the risk of Phenobarbital's side effects


• Methoxyflurane and the risk of its side effects may be increased by Phenobarbital


• Beta-adrenergic blockers (eg, propranolol), clozapine, corticosteroids (eg, hydrocortisone), digitoxin, doxycycline, estrogens, imatinib, metronidazole, oral contraceptives (eg, norethindrone/ethinyl estradiol), quinidine, theophyllines, voriconazole, or warfarin because their effectiveness may be decreased by Phenobarbital

This may not be a complete list of all interactions that may occur. Ask your health care provider if Phenobarbital may interact with other medicines that you take. Check with your health care provider before you start, stop, or change the dose of any medicine.

How to use Phenobarbital:

Use Phenobarbital as directed by your doctor. Check the label on the medicine for exact dosing instructions.

• Phenobarbital is usually given as an injection at your doctor's office, hospital, or clinic. If you will be using Phenobarbital at home, a health care provider will teach you how to use it. Be sure you understand how to use Phenobarbital. Follow the procedures you are taught when you use a dose. Contact your health care provider if you have any questions.


• Do not use Phenobarbital if it contains particles, is cloudy or discolored, or if the vial is cracked or damaged.


• Do not suddenly stop using Phenobarbital or change the dose without checking with your doctor.


• Keep this product, as well as syringes and needles, out of the reach of children and pets. Do not reuse needles, syringes, or other materials. Ask your health care provider how to dispose of these materials after use. Follow all local rules for disposal.


• If you miss a dose of Phenobarbital, use it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not use 2 doses at once.

Ask your health care provider any questions you may have about how to use Phenobarbital.

Important safety information:

• Phenobarbital may cause drowsiness. These effects may be worse if you take it with alcohol or certain medicines. Use Phenobarbital with caution. Do not drive or perform other possibly unsafe tasks until you know how you react to it.


• Do not drink alcohol or use medicines that may cause drowsiness (eg, sleep aids, muscle relaxers) while you are using Phenobarbital; it may add to their effects. Ask your pharmacist if you have questions about which medicines may cause drowsiness.


• Hormonal birth control (eg, birth control pills) may not work as well while you are using Phenobarbital. To prevent pregnancy, use an extra form of birth control (eg, condoms).


• Use Phenobarbital with caution in the ELDERLY; they may be more sensitive to its effects.


• Phenobarbital should not be used in CHILDREN younger than 12 years old; safety and effectiveness in these children have not been confirmed.


• PREGNANCY and BREAST-FEEDING: Phenobarbital has been shown to cause harm to the fetus. If you think you may be pregnant, contact your doctor. You will need to discuss the benefits and risks of using Phenobarbital while you are pregnant. Phenobarbital is found in breast milk. If you are or will be breast-feeding while you use Phenobarbital, check with your doctor. Discuss any possible risks to your baby.

When used for long periods of time or at high doses, Phenobarbital may not work as well and may require higher doses to obtain the same effect as when originally taken. This is known as TOLERANCE. Talk with your doctor if Phenobarbital stops working well. Do not take more than prescribed.

Some people who use Phenobarbital for a long time may develop a need to continue taking it. People who take high doses are also at risk. This is known as DEPENDENCE or addiction. If you stop taking Phenobarbital suddenly, you may have WITHDRAWAL symptoms. These may include anxiety, convulsion or seizures, dizziness, increasing weakness, lightheadedness, muscle twitching, nausea, sleeplessness, trembling hands and fingers, unusual visions, vomiting.

Possible side effects of Phenobarbital:

All medicines may cause side effects, but many people have no, or minor side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome:

Agitated mood; clumsiness; confusion; dizziness; excessive daytime drowsiness; headache; injection site reactions; lightheadedness; low blood pressure; nausea; slow heartbeat; slowed breathing; vomiting.

Seek medical attention right away if any of these SEVERE side effects occur:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); difficulty breathing; liver damage.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. To report side effects to the appropriate agency, please read the Guide to Reporting Problems to FDA.

See also: Phenobarbital side effects (in more detail)

If OVERDOSE is suspected:

Contact 1-800-222-1222 (the American Association of Poison Control Centers), your local poison control center, or emergency room immediately. Symptoms may include change in size of pupil; cold, clammy skin; deep sleep; loss of consciousness; slowed or fast breathing.

Proper storage of Phenobarbital:

Store Phenobarbital at room temperature between 68 and 77 degrees F (20 and 25 degrees C). Store away from heat, moisture, and light. Do not store in the bathroom. Keep Phenobarbital out of the reach of children and away from pets.

General information:

• If you have any questions about Phenobarbital, please talk with your doctor, pharmacist, or other health care provider.


• Phenobarbital is to be used only by the patient for whom it is prescribed. Do not share it with other people.


• If your symptoms do not improve or if they become worse, check with your doctor.


• Check with your pharmacist about how to dispose of unused medicine.

This information is a summary only. It does not contain all information about Phenobarbital. If you have questions about the medicine you are taking or would like more information, check with your doctor, pharmacist, or other health care provider.

Issue Date: February 1, 2012

Database Edition 12.1.1.002

Copyright © 2012 Wolters Kluwer Health, Inc.

More Phenobarbital resources

• Phenobarbital Side Effects (in more detail)
• Phenobarbital Use in Pregnancy & Breastfeeding
• Drug Images
• Phenobarbital Drug Interactions
• Phenobarbital Support Group
• 5 Reviews for Phenobarbital - Add your own review/rating

• Phenobarbital Professional Patient Advice (Wolters Kluwer)


• Phenobarbital Monograph (AHFS DI)


• Phenobarbital Prescribing Information (FDA)


• phenobarbital Concise Consumer Information (Cerner Multum)

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