Phenobarbital Tablets

Phenobarbital is a barbiturate medication that can help regulate seizures. This medication comes in a tablet form. Talk to your healthcare provider about the interactions and side effects of this medication.

What is this medication?

PHENOBARBITAL (fee noe BAR bi tal) prevents and controls seizures in people with epilepsy. It may also be used to treat anxiety or cause drowsiness, including before a procedure. It works by calming overactive nerves in your body.

This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.

Advertisement

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy

What should I tell my care team before I take this medication?

They need to know if you have any of these conditions:

  • Frequently drink alcohol
  • Kidney disease
  • Liver disease
  • Lung disease or breathing problems
  • Porphyria
  • Substance use disorder
  • Suicidal thoughts, plans, or attempt by you or a family member
  • An unusual or allergic reaction to phenobarbital, other barbiturates, other medications, lactose, foods, dyes, or preservatives
  • Pregnant or trying to get pregnant
  • Breast-feeding

How should I use this medication?

Take this medication by mouth with a full glass of water. Follow the directions on the prescription label. Take your medication at regular intervals. Do not take your medication more often than directed. Do not stop taking except on your care team's advice. If you have been taking this medication regularly and suddenly stop taking it, you may increase the risk of seizures. Your care team may gradually reduce the dose.

Talk to your care team about the use of this medication in children. Special care may be needed.

Patients over 65 years old may have a stronger reaction and need a smaller dose.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.

NOTE: This medicine is only for you. Do not share this medicine with others.

Advertisement

What if I miss a dose?

If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.

What may interact with this medication?

Do not take this medication with any of the following:

  • Certain medications used to treat HIV infection or AIDS that are given in combination with cobicistat
  • Other barbiturates
  • Primidone
  • Voriconazole

This medication may also interact with the following:

  • Alcohol or medications that contain alcohol
  • Antihistamines
  • Medications for depression, anxiety, or mental health conditions
  • Medications for pain including pentazocine, buprenorphine, butorphanol, nalbuphine, tramadol, and propoxyphene
  • Medications for sleep
  • Muscle relaxants
  • Steroid medications like prednisone or cortisone

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

Advertisement

What should I watch for while using this medication?

Visit your care team for regular checks on your progress.

This medication may cause serious skin reactions. They can happen weeks to months after starting the medication. Contact your care team right away if you notice fevers or flu-like symptoms with a rash. The rash may be red or purple and then turn into blisters or peeling of the skin. Or, you might notice a red rash with swelling of the face, lips or lymph nodes in your neck or under your arms.

If you are taking this medication for seizures, wear a medical identification bracelet or chain to say you have seizures, and carry a card that lists all your medications.

You may get drowsy or dizzy. Do not drive, use machinery, or do anything that needs mental alertness until you know how this medication affects you. Do not stand or sit up quickly, especially if you are an older patient. This reduces the risk of dizzy or fainting spells. Alcohol may interfere with the effect of this medication. Avoid alcoholic drinks.

Estrogen and/or progestin may not work as well while you are taking this medication. If you are using this medication for contraception, talk to your care team about using a second type of contraception. A barrier contraceptive, such as a condom or diaphragm, is recommended.

The use of this medication may increase the chance of suicidal thoughts or actions. Pay special attention to how you are responding while on this medication. Any worsening of mood, or thoughts of suicide or dying should be reported to your care team right away.

Women who become pregnant while using this medication may enroll in the North American Antiepileptic Drug Pregnancy Registry by calling 1-888-233-2334. This registry collects information about the safety of antiepileptic medication use during pregnancy.

This medication may cause a decrease in vitamin D and folic acid. You should make sure that you get enough vitamins while you are taking this medication. Discuss the foods you eat and the vitamins you take with your care team.

What side effects may I notice from receiving this medication?

Side effects that you should report to your care team as soon as possible:

  • Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat
  • CNS depression—slow or shallow breathing, shortness of breath, feeling faint, dizziness, confusion, trouble staying awake
  • Thoughts of suicide or self-harm, worsening mood, feelings of depression

Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):

  • Dizziness
  • Drowsiness
  • Headache
  • Nausea

This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Where should I keep my medication?

Keep out of the reach of children and pets. This medication can be abused. Keep your medication in a safe place to protect it from theft. Do not share this medication with anyone. Selling or giving away this medication is dangerous and against the law.

This medication may cause accidental overdose and death if taken by other adults, children, or pets. Mix any unused medication with a substance like cat litter or coffee grounds. Then throw the medication away in a sealed container like a sealed bag or a coffee can with a lid. Do not use the medication after the expiration date.

Store at room temperature between 20 and 25 degrees C (68 and 77 degrees F). Keep container tightly closed. Protect from light.

NOTE: This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.

Copyright ©2024 Elsevier Inc. All Rights Reserved.

Terms of use.

Note: Introduction and Additional Common Questions written and medically approved by Cleveland Clinic professionals.

Ad
Call Appointment Center 24/7 866.320.4573
Questions 216.444.2200