Phenobarbital is in a group of drugs called barbiturates (bar-BIT-chur-ates). Phenobarbital slows the activity of your brain and nervous system.
Phenobarbital is used to treat or prevent seizures. It is also used short-term to treat insomnia, or as a sedative before surgery.
Phenobarbital may also be used for purposes not listed in this medication guide.
An indication is a term used for the list of condition or symptom or illness for which the medicine is prescribed or used by the patient. For example, acetaminophen or paracetamol is used for fever by the patient, or the doctor prescribes it for a headache or body pains. Now fever, headache and body pains are the indications of paracetamol. A patient should be aware of the indications of medications used for common conditions because they can be taken over the counter in the pharmacy meaning without prescription by the Physician.
Sedative. Sedation is obtainable within an hour, and in adequate dosage, the duration of action is more than six hours. Included in the more common conditions in which the sedative action of this class of drugs is desired are anxiety-tension states, hyperthyroidism, essential hypertension, nausea and vomiting of functional origin, motion sickness, acute labyrinthitis, pylorospasm in infants, chorea and cardiac failure. Phenobarbital is also a useful adjunct in treatment of hemorrhage from the respiratory or gastrointestinal tract. Phenobarbital controls anxiety, decreases muscular activity and lessens nervous excitability in hyperthyroid patients. However, thyrotoxic individuals occasionally react poorly to barbiturates.
Hypnotic, for the short-term treatment of insomnia, since it appears to lose its effectiveness for sleep induction and sleep maintenance after 2 weeks.
Long-term anticonvulsant, (Phenobarbital, mephobarbital and metharbital) for the treatment of generalized tonic-clonic and cortical focal seizures. And, in the emergency control of certain acute convulsive episodes, e.g., those associated with status epilepticus, cholera, eclampsia, cerebral hemorrhage, meningitis, tetanus, and toxic reactions to strychnine or local anesthetics. Phenobarbital sodium may be administered intramuscularly or intravenously as an anticonvulsant for emergency use. When administered intravenously, it may require 15 or more minutes before reaching peak concentrations in the brain. Therefore, injecting Phenobarbital sodium until the convulsions stop may cause the brain level to exceed that required to control the convulsions and lead to severe barbiturate-induced depression.
Phenobarbital is indicated in pediatric patients as an anticonvulsant and as a sedative, including its preoperative and postoperative use.
How should I 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.
Uses of Phenobarbital in details
There are specific as well as general uses of a drug or medicine. A medicine can be used to prevent a disease, treat a disease over a period or cure a disease. It can also be used to treat the particular symptom of the disease. The drug use depends on the form the patient takes it. It may be more useful in injection form or sometimes in tablet form. The drug can be used for a single troubling symptom or a life-threatening condition. While some medications can be stopped after few days, some drugs need to be continued for prolonged period to get the benefit from it.
This medication is used alone or with other medications to control seizures. Controlling and reducing seizures lets you do more of your normal daily activities, reduces your risk of harm when you lose consciousness, and lessens your risk for a possibly life-threatening condition of frequent, repeated seizures. Phenobarbital belongs to a class of drugs known as barbiturate anticonvulsants/hypnotics. It works by controlling the abnormal electrical activity in the brain that occurs during a seizure. This medication is also used for a short time (usually no more than 2 weeks) to help calm you or help you sleep during periods of anxiety. It works by affecting certain parts of the brain to cause calming.
How to use Phenobarbital
Take this medication by mouth with or without food, usually once daily at bedtime for seizure control, or as directed by your doctor. Take with food or milk if stomach upset occurs. If you are using the liquid form of this medication, measure the dose carefully using a special measuring device/cup. Do not use a household spoon because you may not get the correct dose.
Dosage is based on your medical condition, Phenobarbital blood levels, and response to treatment. The dosage in children may also be based on weight.
Your doctor may direct you to start this medication at a low dose and gradually increase your dose to prevent side effects such as drowsiness and dizziness. Follow your doctor's instructions carefully. Do not take more or less of this drug than prescribed.
It may take several weeks to reach the best dose for you and completely control your seizures. This medication works best when the amount of drug in your body is kept at a constant level. Therefore, take it at the same time(s) each day.
Do not stop taking this medication (and other anticonvulsant medications) without consulting your doctor. Your seizures may worsen or cause a very severe seizure that is difficult to treat (status epilepticus) when this drug is suddenly stopped.
This medication may cause withdrawal reactions, especially if it has been used regularly for a long time or in high doses. In such cases, withdrawal symptoms (such as anxiety, hallucinations, twitching, trouble sleeping) may occur if you suddenly stop using this medication. Withdrawal from Phenobarbital can be severe and include seizures and (rarely) death. To prevent withdrawal reactions, your doctor may reduce your dose gradually. Consult your doctor or pharmacist for more details, and report any withdrawal reactions right away.
Along with its benefits, this medication may rarely cause abnormal drug-seeking behavior (addiction). This risk may be increased if you have abused alcohol or drugs in the past. Take this medication exactly as prescribed to lessen the risk of addiction.
When this medication is used for a long time for anxiety or to help you sleep, it may not work as well. Phenobarbital should only be used for a short time for anxiety or sleep. Talk with your doctor if this medication stops working well.
Tell your doctor if your anxiety or seizure control worsens (such as the number of seizures increases).
A barbiturate that is metabolized to Phenobarbital. It has been used for similar purposes, especially in epilepsy, but there is no evidence mephobarbital offers any advantage over Phenobarbital.
Suggested doses of Phenobarbital for specific indications are as follows:
Oral Dosage (as recommended by the American Academy of Pediatrics):
Preoperative: 1 to 3 mg/kg.
1. Daytime sedative: 30 to 120 mg daily in 2 to 3 divided doses.
2. Bedtime hypnotic: 100 to 320 mg.
3. Anticonvulsant: 50 to 100 mg 2 to 3 times daily.
Dosages of Phenobarbital must be individualized with full knowledge of their particular characteristics and recommended rate of administration. Factors of consideration are the patient's age, weight, and condition.
Parenteral routes should be used only when oral administration is impossible or impractical.
Anticonvulsant use: A therapeutic anticonvulsant level of Phenobarbital in serum is 10 to 25 µg/mL. To achieve the blood levels considered therapeutic in children, higher per-kilogram dosages are generally necessary for Phenobarbital and most other anticonvulsants. In children and infants, Phenobarbital at loading dose of 15 to 20 mg/kg produces blood levels of about 20 µg/mL shortly after administration.
In status epilepticus, it is imperative to achieve therapeutic blood levels of Phenobarbital as rapidly as possible. Because a barbiturate-induced depression may occur along with a postictal depression once the seizures are controlled, it is important, therefore, to use the minimal amount required, and to wait for the anticonvulsant effect to develop before administering a second dose.
Phenobarbital has been used in the treatment and prophylaxis of febrile seizures. However, it has not been established that prevention of febrile seizures influences the subsequent development of epilepsy.
Special patient population: Dosage should be reduced in the elderly or debilitated because these patients may be more sensitive to Phenobarbital. Dosage should be reduced for patients with impaired renal function or hepatic disease.
15 mg - Each white round tablet imprinted Þ 026 contains 15 mg of Phenobarbital. Tablets are supplied in bottles of 1000 (NDC 0228-2026-96).
30 mg - Each white, round, scored tablet imprinted Þ 028 contains 30 mg of Phenobarbital. Tablets are supplied in bottles of 1000 (NDC 0228-2028-96).
100 mg - Each white, round, scored tablet imprinted Þ 030 contains 100 mg of Phenobarbital. Tablets are supplied in bottles of 1000 (NDC 0228-2030-96).
Dispense in well-closed containers as defined in the USP. Store at controlled room temperature 15º- 30º C (59º- 86º F).
Red, clear elixir contains 20 mg of Phenobarbital per teaspoon (5 ml). Alcohol 13% by volume. Elixir is supplied in pints (NDC 0228-2024-16).
Preserve and dispense in tight, light- resistant containers as defined in the USP. Store at controlled room temperature 15º- 30ºC (59º- 86º F).
Most reports of clinically significant drug interactions occurring with the barbiturates have involved Phenobarbital.
1. Anticoagulants: Phenobarbital lowers the plasma levels of dicumarol (name previously used: bishydorxycoumarin) and causes a decrease in anticoagulant activity as measured by the prothrombin time. Phenobarbital can induce hepatic microsomal enzymes resulting in increased metabolism and decreased anticoagulant response of oral anticoagulants (e.g., warfarin, acenocournarol, dicumarol, and phenprocoumon). Patients stabilized on anticoagulant therapy may require dosage adjustments if Phenobarbital is added to or withdrawn from their dosage regimen.
2. Corticosteroids: Phenobarbital appears to enhance the metabolism of exogenous corticosteroids probably through the induction of hepatic microsomal enzymes. Patients stabilized on corticosteroid therapy may require dosage adjustments if Phenobarbital is added to or withdrawn from their dosage regimen.
3. Griseofulvin: Phenobarbital appears to interfere with the absorption of orally administered griseofulvin, thus decreasing its blood level. The effect of the resultant decreased blood levels of griseofulvin on therapeutic response has not been established. However, it would be preferable to avoid concomitant administration of these drugs.
4. Doxycycline: Phenobarbital has been shown to shorten the half- life of doxycycline for as long as 2 weeks after barbiturate therapy is discontinued. This mechanism is probably through the induction of hepatic microsomal enzymes that metabolize the antibiotic. If Phenobarbital and doxycycline are administered concurrently, the clinical response to doxycycline should be monitored closely.
5. Phenytoin, sodium valproate, valproic acid: The effect of Phenobarbital on the metabolism of phenytoin appears to be variable. Some investigators report an accelerating effect, while others report no effect. Because the effect of Phenobarbital on the metabolism of phenytoin is not predictable, phenytoin and Phenobarbital blood levels should be monitored more frequently if these drugs are given concurrently. Sodium valproate and valproic acid appear to decrease Phenobarbital metabolism; therefore, Phenobarbital blood levels should be monitored and appropriate dosage adjustments made as indicated.
6. Central nervous system depressants: The concomitant use of other central nervous system depressants including other sedatives or hypnotics, antihistamines, tranquilizers, or alcohol, may produce additive depressant effects.
7. Monoamine oxidase inhibitors (MAOIs): MAOIs prolong the effects of Phenobarbital probably because metabolism of the Phenobarbital is inhibited.
8. Estradiol, estrone, progesterone and other steroidal hormones: Pretreatment with or concurrent administration of Phenobarbital may decrease the effect of estradiol by increasing its metabolism. There have been reports of patients treated with antiepileptic drugs (e.g., Phenobarbital) who became pregnant while taking oral contraceptives. An alternate contraceptive method might be suggested to women taking Phenobarbital.
Other reported reactions: Headache, injection site reactions, hypersensitivity reactions (angioedema skin rashes, exfoliative dermatitis), fever, liver damage, megaloblastic anemia following chronic Phenobarbital use.
DRUG ABUSE AND DEPENDENCE
Phenobarbital may be habit forming:
Tolerance, psychological dependence, and physical dependence may occur especially following prolonged use of high doses of Phenobarbital. As tolerance to Phenobarbital develops, the amount needed to maintain the same level of intoxication increases; tolerance to a fatal dosage, however, does not increase more than two-fold. As this occurs, the margin between an intoxicating dosage and fatal dosage becomes smaller.
Symptoms of acute intoxication with Phenobarbital include unsteady gait, slurred speech, and sustained nystagmus. Mental signs of chronic intoxication include confusion, poor judgment, irritability, insomnia, and somatic complaints.
Symptoms of Phenobarbital dependence are similar to those of chronic alcoholism. If an individual appears to be intoxicated with alcohol to a degree that is radically disproportionate to the amount of alcohol in his or her blood, the use of barbiturates should be suspected. The lethal dose of a barbiturate is far less if alcohol is also ingested. The symptoms of Phenobarbital withdrawal can be severe and may cause death. Minor withdrawal symptoms may appear 8 to 12 hours after the last dose of Phenobarbital. These symptoms usually appear in the following order: anxiety, muscle twitching, tremor of hands and fingers, progressive weakness, dizziness, distortion in visual perception, nausea, vomiting, insomnia, and orthostatic hypotension. Major withdrawal symptoms (convulsions and delirium) may occur within 16 hours and last up to 5 days after abrupt cessation of this drug. Intensity of withdrawal symptoms gradually declines over a period of approximately 15 days. Individuals susceptible to Phenobarbital abuse and dependence include alcoholics and opiate abusers, as well as other sedative- hypnotic and amphetamine abusers.
Drug dependence on Phenobarbital arises from repeated administration of the barbiturate or an agent with barbiturate- like effect on a continuous basis, generally in amounts exceeding therapeutic dose levels. The characteristics of drug dependence on Phenobarbital include: (a) a strong desire or need to continue taking the drug, (b) a tendency to increase the dose, (c) a psychic dependence on the effects of the drug related to subjective and individual appreciation of those effects, and (d) a physical dependence on the effects of the drug requiring its presence for maintenance of homeostasis and resulting in a definite, characteristic, and self-limited abstinence syndrome when the drug is withdrawn.
Treatment of Phenobarbital dependence consists of cautious and gradual withdrawal of the drug. One method involves substituting a 30 mg dose of Phenobarbital for each 100 to 200 mg dose that the patient has been taking. The total daily amount of Phenobarbital is then administered in 3 to 4 divided doses, not to exceed 600 mg daily. Should signs of withdrawal occur on the first day of treatment, a loading dose of 100 to 200 mg of Phenobarbital may be administered IM in addition to the oral dose. After stabilization on Phenobarbital, the total daily dose is decreased by 30 mg a day as long as withdrawal is proceeding smoothly. A modification of this regimen involves initiating treatment at the patient's regular dosage level and decreasing the daily dosage by 10 percent if tolerated by the patient.
Infants physically dependent on Phenobarbital may be given a lower dose of Phenobarbital at 3 to 10 mg/kg/day. After withdrawal symptoms (hyperactivity, disturbed sleep, tremors, hyperreflexia) are relieved, the dosage of Phenobarbital should be gradually decreased and completely withdrawn over a 2-week period.
Do not use Phenobarbital if you are pregnant. It could harm the unborn baby. Phenobarbital may also cause addiction or withdrawal symptoms in a newborn if the mother takes the medication during pregnancy.
Phenobarbital can make birth control pills less effective. Ask your doctor about using a non-hormone method of birth control (such as a condom, diaphragm, spermicide) to prevent pregnancy while taking Phenobarbital.
Phenobarbital may cause a severe allergic reaction. Stop taking Phenobarbital and get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.
Do not stop using Phenobarbital without first talking to your doctor, even if you feel better. You may have increased seizures if you stop using Phenobarbital suddenly. You will need to use less and less before you stop the medication completely.
Some people using this medicine have engaged in activity such as driving, eating, or making phone calls and later having no memory of the activity. If this happens to you, stop taking Phenobarbital and talk with your doctor about another treatment for your sleep disorder.
Phenobarbital may be habit-forming and should be used only by the person it was prescribed for. Keep the medication in a secure place where others cannot get to it.
Active ingredient matches for Phenobarbital:
Unit description / dosage (Manufacturer)
Tablet; Oral; Phenobarbital 100 mg
Tablet; Oral; Phenobarbital 15 mg
Tablet; Oral; Phenobarbital 30 mg
Tablet; Oral; Phenobarbital 60 mg
Tablet; Oral; Phenobarbital 5 mg
Injectable; Injection; Phenobarbital Sodium 120 mg / ml
Injectable; Injection; Phenobarbital Sodium 30 mg / ml
DTP/NCI. "phenobarbital: The NCI Development Therapeutics Program (DTP) provides services and resources to the academic and private-sector research communities worldwide to facilitate the discovery and development of new cancer therapeutic agents.". https://dtp.cancer.gov/dtpstandard/s... (accessed September 17, 2018).
The results of a survey conducted on ndrugs.com for Phenobarbital are given in detail below. The results of the survey conducted are based on the impressions and views of the website users and consumers taking Phenobarbital. We implore you to kindly base your medical condition or therapeutic choices on the result or test conducted by a physician or licensed medical practitioners.
1 consumer reported useful
Was the Phenobarbital drug useful in terms of decreasing the symptom or the disease? According to the reports released by ndrugs.com website users, the below mentioned percentages of users say the drug is useful / not useful to them in decreasing their symptoms/disease. The usefulness of the drug depends on many factors, like severity of the disease, perception of symptom, or disease by the patient, brand name used [matters only to a certain extent], other associated conditions of the patient. If the drug is not effective or useful in your case, you need to meet the doctor to get re-evaluated about your symptoms/disease, and he will prescribe an alternative drug.
Consumer reported price estimates
No survey data has been collected yet
2 consumers reported time for results
To what extent do I have to use Phenobarbital before I begin to see changes in my health conditions? As part of the reports released by ndrugs.com website users, it takes 3 month and a few days before you notice an improvement in your health conditions. Please note, it doesn't mean you will start to notice such health improvement in the same time frame as other users. There are many factors to consider, and we implore you to visit your doctor to know how long before you can see improvements in your health while taking Phenobarbital. To get the time effectiveness of using Phenobarbital drug by other patients, please click here.
> 3 month
1 consumer reported age
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