Medically reviewed by Drugs.com. Last updated on May 28, 2022.
Uses of Phenobarbital Tablets:
- It is used to help control certain kinds of seizures.
- It is used to treat sleep problems.
- It may be given to you for other reasons. Talk with the doctor.
What do I need to tell my doctor BEFORE I take Phenobarbital Tablets?
- If you have an allergy to phenobarbital or any other part of this medicine (phenobarbital tablets).
- If you are allergic to this medicine (phenobarbital tablets); any part of this medicine (phenobarbital tablets); or any other drugs, foods, or substances. Tell your doctor about the allergy and what signs you had.
- If you have any of these health problems: A block in the airway, liver disease, or shortness of breath.
- If you have ever had porphyria.
This is not a list of all drugs or health problems that interact with this medicine (phenobarbital tablets).
Tell your doctor and pharmacist about all of your drugs (prescription or OTC, natural products, vitamins) and health problems. You must check to make sure that it is safe for you to take this medicine (phenobarbital tablets) with all of your drugs and health problems. Do not start, stop, or change the dose of any drug without checking with your doctor.
What are some things I need to know or do while I take Phenobarbital Tablets?
- Tell all of your health care providers that you take this medicine (phenobarbital tablets). This includes your doctors, nurses, pharmacists, and dentists.
- This medicine may be habit-forming with long-term use.
- Do not stop taking this medicine (phenobarbital tablets) all of a sudden without calling your doctor. You may have a greater risk of signs of withdrawal. If you need to stop this medicine (phenobarbital tablets), you will want to slowly stop it as ordered by your doctor.
- If you have been taking this medicine (phenobarbital tablets) for a long time or at high doses, it may not work as well and you may need higher doses to get the same effect. This is known as tolerance. Call your doctor if this medicine (phenobarbital tablets) stops working well. Do not take more than ordered.
- Have your blood work checked if you are on this medicine (phenobarbital tablets) for a long time. Talk with your doctor.
- Avoid driving and doing other tasks or actions that call for you to be alert until you see how this medicine (phenobarbital tablets) affects you.
- Avoid drinking alcohol while taking this medicine (phenobarbital tablets).
- Talk with your doctor before you use other drugs and natural products that slow your actions.
- If you are 65 or older, use this medicine (phenobarbital tablets) with care. You could have more side effects.
- Use with care in children. Talk with the doctor.
- Birth control pills and other hormone-based birth control may not work as well to prevent pregnancy. Use 2 kinds of birth control while taking this medicine (phenobarbital tablets).
- This medicine may cause harm to the unborn baby if you take it while you are pregnant. If you are pregnant or you get pregnant while taking this medicine (phenobarbital tablets), call your doctor right away.
- Taking this medicine (phenobarbital tablets) in the third trimester of pregnancy may lead to withdrawal in the newborn. Talk with the doctor.
- Tell your doctor if you are breast-feeding. You will need to talk about any risks to your baby.
How is this medicine (Phenobarbital Tablets) best taken?
Use this medicine (phenobarbital tablets) as ordered by your doctor. Read all information given to you. Follow all instructions closely.
- Take with or without food. Take with food if it causes an upset stomach.
What do I do if I miss a dose?
- Take a missed dose as soon as you think about it.
- If it is close to the time for your next dose, skip the missed dose and go back to your normal time.
- Do not take 2 doses at the same time or extra doses.
What are some side effects that I need to call my doctor about right away?
WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:
For all uses of this medicine (phenobarbital tablets):
- Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.
- Mental, mood, or behavior changes that are new or worse.
- Feeling confused.
- Very nervous and excitable.
- Shortness of breath.
- Bone pain.
- A very bad skin reaction (Stevens-Johnson syndrome/toxic epidermal necrolysis) may happen. It can cause very bad health problems that may not go away, and sometimes death. Get medical help right away if you have signs like red, swollen, blistered, or peeling skin (with or without fever); red or irritated eyes; or sores in your mouth, throat, nose, or eyes.
- If seizures are worse or not the same after starting this medicine (phenobarbital tablets).
What are some other side effects of Phenobarbital Tablets?
All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:
- Feeling sleepy.
- Upset stomach or throwing up.
These are not all of the side effects that may occur. If you have questions about side effects, call your doctor. Call your doctor for medical advice about side effects.
You may report side effects to the FDA at 1-800-332-1088. You may also report side effects at https://www.fda.gov/medwatch.
If OVERDOSE is suspected:
If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.
How do I store and/or throw out Phenobarbital Tablets?
- Store at room temperature.
- Keep lid tightly closed.
- Protect from light.
- Store in a dry place. Do not store in a bathroom.
- Keep all drugs in a safe place. Keep all drugs out of the reach of children and pets.
- Throw away unused or expired drugs. Do not flush down a toilet or pour down a drain unless you are told to do so. Check with your pharmacist if you have questions about the best way to throw out drugs. There may be drug take-back programs in your area.
Consumer information use
- If your symptoms or health problems do not get better or if they become worse, call your doctor.
- Do not share your drugs with others and do not take anyone else's drugs.
- Some drugs may have another patient information leaflet. Check with your pharmacist. If you have any questions about this medicine (phenobarbital tablets), please talk with your doctor, nurse, pharmacist, or other health care provider.
- If you think there has been an overdose, call your poison control center or get medical care right away. Be ready to tell or show what was taken, how much, and when it happened.
More about phenobarbital
- Side effects
- Drug interactions
- Dosage information
- During pregnancy or Breastfeeding
- Reviews (30)
- Drug images
- Pricing & coupons
- En español
- Drug class: barbiturate anticonvulsants
Related treatment guides
Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.