PHENOBARBITAL tablet

United States - English - NLM (National Library of Medicine)

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Active ingredient:
PHENOBARBITAL (UNII: YQE403BP4D) (PHENOBARBITAL - UNII:YQE403BP4D)
Available from:
Clinical Solutions Wholesale, LLC
Administration route:
ORAL
Prescription type:
PRESCRIPTION DRUG
Therapeutic indications:
- Sedative - Anticonvulsant – For the treatment of generalized and partial seizures. Phenobarbital is contraindicated in patients who are hypersensitive to barbiturates, in patients with a history of manifest or latent porphyria, and in patients with marked impairment of liver function or respiratory disease in which dyspnea or obstruction is evident. Phenobarbital is a Schedule IV drug. Barbiturates may be habit forming. Tolerance, psychological dependence, and physical dependence may occur, especially following prolonged use of high doses of barbiturates. Daily administration in excess of 400 mg of pentobarbital or secobarbital for approximately 90 days is likely to produce some degree of physical dependence. A dosage of 600 to 800 mg taken for at least 35 days is sufficient to produce withdrawal seizures. The average daily dose for the barbiturate addict is usually about 1.5 g. As tolerance to barbiturates develops, the amount needed to maintain the same level of intoxication increases; tolerance to a fata
Product summary:
Phenobarbital Tablets, USP 16.2 mg: White, round, tablets scored on one side and debossed “e5" above the score and "110” below the score. The other side is plain. Available in bottles of 100 tablets, NDC 13517-110-01, 1000 tablets, NDC 13517-110-10, 30 tablets in blister pack NDC 58118-1110-8 Phenobarbital Tablets, USP 32.4 mg: White, round, tablets scored on one side and debossed “e5" above the score and "111” below the score. The other side is plain. Available in bottles of 100 tablets, NDC 13517-111-01 and 1000 tablets, NDC 13517-111-10. Phenobarbital Tablets, USP 64.8 mg: White, round, tablets scored on one side and debossed “e5" above the score and "112” below the score. The other side is plain. Available in bottles of 100 tablets, NDC 13517-112-01 and 1000 tablets, NDC 13517-112-10. Phenobarbital Tablets, USP 97.2 mg: White, round, tablets scored on one side and debossed “e5" above the score and "113” below the score. The other side is plain. Available in bottles of 100 tablets, NDC 13517-113-01 and 1000 tablets, NDC 13517-113-10. Store at 20°- 25°C (68°- 77°F) [See USP Controlled Room Temperature]. Protect from light and moisture. Dispense in a tight, light-resistant container as defined in the USP using a child-resistant closure. Manufactured for: e5 Pharma, LLC Boca Raton, FL 33432 Repackaged By: Clinical Solutions Wholesale Franklin, TN 37067
Authorization status:
unapproved drug other
Authorization number:
58118-1110-8

PHENOBARBITAL- phenobarbital tablet

Clinical Solutions Wholesale, LLC

Disclaimer: This drug has not been found by FDA to be safe and effective, and this labeling has not been

approved by FDA. For further information about unapproved drugs, click here.

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PHENOBARBITAL TABLETS, USP

DESCRIPTION

The barbiturates are nonselective central nervous system (CNS) depressants that are primarily used as

sedative-hypnotics. In subhypnotic doses, they are also used as anticonvulsants. The barbiturates and

their sodium salts are subject to control under the Federal Controlled Substances Act.

Phenobarbital is a barbituric acid derivative and occurs as white, odorless, small crystals or crystalline

powder that is very slightly soluble in water; soluble in alcohol, in ether, and in solutions of fixed alkali

hydroxides and carbonates; sparingly soluble in chloroform. Phenobarbital is 5-ethyl-5-

phenylbarbituric acid. Phenobarbital is a substituted pyrimidine derivative in which the basic structure is

barbituric acid, a substance that has no CNS activity. CNS activity is obtained by substituting alkyl,

alkenyl, or aryl groups on the pyrimidine ring. It has the following structural formula:

M.W. = 232.24

Each phenobarbital tablet contains 16.2 mg, 32.4 mg, 64.8 mg, or 97.2 mg of phenobarbital, USP.

INACTIVE INGREDIENT

Inactive ingredients include: colloidal silicon dioxide, lactose anhydrous, magnesium stearate,

microcrystalline cellulose, sodium starch glycolate, and stearic acid.

CLINICAL PHARMACOLOGY

Barbiturates are capable of producing all levels of CNS mood alteration, from excitation to mild

sedation, hypnosis, and deep coma. Overdosage can produce death. In high enough therapeutic doses,

barbiturates induce anesthesia.

Barbiturates depress the sensory cortex, decrease motor activity, alter cerebellar function, and produce

drowsiness, sedation, and hypnosis.

Barbiturate-induced sleep differs from physiologic sleep. Sleep laboratory studies have demonstrated

that barbiturates reduce the amount of time spent in the rapid eye movement (REM) phase of sleep or the

dreaming stage. Also, Stages III and IV sleep are decreased. Following abrupt cessation of barbiturates

used regularly, patients may experience markedly increased dreaming, nightmares, and/or insomnia.

Therefore, withdrawal of a single therapeutic dose over 5 or 6 days has been recommended to lessen

the REM rebound and disturbed sleep that contribute to the drug withdrawal syndrome (for example,

decrease the dose from 3 to 2 doses a day for 1 week).

In studies, secobarbital sodium and pentobarbital sodium have been found to lose most of their

effectiveness for both inducing and maintaining sleep by the end of 2 weeks of continued drug

administration even with the use of multiple doses. As with secobarbital sodium and pentobarbital

sodium, other barbiturates (including amobarbital) might be expected to lose their effectiveness for

inducing and maintaining sleep after about 2 weeks. The short-, intermediate-, and, to a lesser degree,

long-acting barbiturates have been widely prescribed for treating insomnia. Although the clinical

literature abounds with claims that the short-acting barbiturates are superior for producing sleep

whereas the intermediate-acting compounds are more effective in maintaining sleep, controlled studies

have failed to demonstrate these differential effects. Therefore, as sleep medications, the barbiturates

are of limited value beyond short-term use.

Barbiturates have little analgesic action at subanesthetic doses. Rather, in subanesthetic doses, these

drugs may increase the reaction to painful stimuli. All barbiturates exhibit anticonvulsant activity in

anesthetic doses; however, of the drugs in this class, only phenobarbital, mephobarbital, and metharbital

are effective as oral anticonvulsants in subhypnotic doses.

Barbiturates are respiratory depressants, and the degree of respiratory depression is dependent upon the

dose. With hypnotic doses, respiratory depression produced by barbiturates is similar to that which

occurs during physiologic sleep and is accompanied by a slight decrease in blood pressure and heart

rate.

Studies in laboratory animals have shown that barbiturates cause reduction in the tone and contractility

of the uterus, ureters, and urinary bladder. However, concentrations of the drugs required to produce

this effect in humans are not reached with sedative-hypnotic doses.

Barbiturates do not impair normal hepatic function but have been shown to induce liver microsomal

enzymes, thus increasing and/or altering the metabolism of barbiturates and other drugs (see

PRECAUTIONS - Drug Interactions).

Pharmacokinetics

Barbiturates are absorbed in varying degrees following oral or parenteral administration. The salts are

more rapidly absorbed than are the acids. The rate of absorption is increased if the sodium salt is

ingested as a dilute solution or taken on an empty stomach.

Duration of action, which is related to the rate at which the barbiturates are redistributed throughout the

body, varies among persons and in the same person from time to time. Phenobarbital is classified as a

long-acting barbiturate when taken orally. Its onset of action is 1 hour or longer, and its duration of

action ranges from 10 to 12 hours.

Barbiturates are weak acids that are absorbed and rapidly distributed to all tissues and fluids, with high

concentrations in the brain, liver, and kidneys. Lipid solubility of the barbiturates is the dominant factor

in their distribution within the body. The more lipid soluble the barbiturate, the more rapidly it

penetrates all tissues of the body. Barbiturates are bound to plasma and tissue proteins to a varying

degree with the degree of binding, increasing directly as a function of lipid solubility.

Phenobarbital has the lowest lipid solubility, lowest plasma binding, lowest brain protein binding, the

longest delay in onset activity, and the longest duration of action. The plasma half-life for phenobarbital

in adults ranges between 53 and 118 hours with a mean of 79 hours. The plasma half-life for

phenobarbital in children and newborns (less than 48 hours old) ranges between 60 to 180 hours with a

mean of 110 hours.

Barbiturates are metabolized primarily by the hepatic microsomal enzyme system, and the metabolic

products are excreted in the urine and, less commonly, in the feces. Approximately 25% to 50% of a

products are excreted in the urine and, less commonly, in the feces. Approximately 25% to 50% of a

dose of phenobarbital is eliminated unchanged in the urine. The excretion of unmetabolized barbiturate

is one feature that distinguishes the long-acting category from those belonging to other categories,

which are almost entirely metabolized. The inactive metabolites of the barbiturates are excreted as

conjugates of glucuronic acid.

INDICATIONS AND USAGE

1. Sedative

2. Anticonvulsant – For the treatment of generalized and partial seizures.

CONTRAINDICATIONS

Phenobarbital is contraindicated in patients who are hypersensitive to barbiturates, in patients with a

history of manifest or latent porphyria, and in patients with marked impairment of liver function or

respiratory disease in which dyspnea or obstruction is evident.

WARNINGS

1. Habit Forming. Phenobarbital may be habit forming. Tolerance and psychological and physical

dependence may occur with continued use (see DRUG ABUSE AND DEPENDENCE and

Pharmacokinetics under CLINICAL PHARMACOLOGY). Patients who have psychologic

dependence on barbiturates may increase the dosage or decrease the dosage interval without

consulting a physician and may subsequently develop a physical dependence on barbiturates. In order

to minimize the possibility of overdosage or the development of dependence, the prescribing and

dispensing of sedative-hypnotic barbiturates should be limited to the amount required for the

interval until the next appointment. Abrupt cessation after prolonged use in a person who is

dependent on the drug may result in withdrawal symptoms, including delirium, convulsions, and

possibly death. Barbiturates should be withdrawn gradually from any patient known to be taking

excessive doses over long periods of time (see DRUG ABUSE AND DEPENDENCE).

2. Acute or Chronic Pain. Caution should be exercised when barbiturates are administered to patients

with acute or chronic pain, because paradoxical excitement could be induced or important symptoms

could be masked. However, the use of barbiturates as sedatives in the postoperative surgical period

and as adjuncts to cancer chemotherapy is well established.

3. Usage in Pregnancy. Barbiturates can cause fetal damage when administered to a pregnant woman.

Retrospective, case-controlled studies have suggested a connection between the maternal

consumption of barbiturates and a higher than expected incidence of fetal abnormalities. Barbiturates

readily cross the placental barrier and are distributed throughout fetal tissues; the highest

concentrations are found in the placenta, fetal liver, and brain. Fetal blood levels approach maternal

blood levels following parenteral administration. Withdrawal symptoms occur in infants born to

women who receive barbiturates throughout the last trimester of pregnancy (see DRUG ABUSE

AND DEPENDENCE). If phenobarbital is used during pregnancy or if the patient becomes

pregnant while taking this drug, the patient should be apprised of the potential hazard to the fetus.

4. Usage in Pediatric Patients. Phenobarbital has been reported to be associated with cognitive deficits

in children taking it for complicated febrile seizures.

5. Synergistic Effects. The concomitant use of alcohol or other CNS depressants may produce additive

CNS depressant effects.

PRECAUTIONS

General

Barbiturates may be habit forming. Tolerance and psychological and physical dependence may occur

with continued use (see DRUG ABUSE AND DEPENDENCE). Barbiturates should be administered

with caution, if at all, to patients who are mentally depressed, have suicidal tendencies, or have a history

of drug abuse.

Elderly or debilitated patients may react to barbiturates with marked excitement, depression, or

confusion. In some persons, especially children, barbiturates repeatedly produce excitement rather than

depression.

In patients with hepatic damage, barbiturates should be administered with caution and initially in reduced

doses. Barbiturates should not be administered to patients showing the premonitory signs of hepatic

coma.

The systemic effects of exogenous and endogenous corticosteroids may be diminished by

phenobarbital. Thus, this product should be administered with caution to patients with borderline

hypoadrenal function, regardless of whether it is of pituitary or of primary adrenal origin.

Information for Patients

The following information and instructions should be given to patients receiving barbiturates.

1. The use of barbiturates carries with it an associated risk of psychological and/or physical

dependence. The patient should be warned against increasing the dose of the drug without

consulting a physician.

2. Barbiturates may impair the mental and/or physical abilities required for the performance of

potentially hazardous tasks, such as driving a car or operating machinery. The patient should be

cautioned accordingly.

3. Alcohol should not be consumed while taking barbiturates. The concurrent use of the barbiturates

with other CNS depressants (e.g., alcohol, narcotics, tranquilizers, and antihistamines) may result in

additional CNS-depressant effects.

Laboratory Tests

Prolonged therapy with barbiturates should be accompanied by periodic laboratory evaluation of organ

systems, including hematopoietic, renal, and hepatic systems (see General under PRECAUTIONS and

ADVERSE REACTIONS).

Drug Interactions

Most reports of clinically significant drug interactions occurring with the barbiturates have involved

phenobarbital. However, the application of these data to other barbiturates appears valid and warrants

serial blood level determinations of the relevant drugs when there are multiple therapies.

1. Anticoagulants. Phenobarbital lowers the plasma levels of dicumarol and causes a decrease in

anticoagulant activity as measured by the prothrombin time. Barbiturates can induce hepatic

microsomal enzymes resulting in increased metabolism and decreased anticoagulant response of oral

anticoagulants (e.g., acenocoumarol, warfarin, dicumarol, and phenprocoumon). Patients stabilized

on anticoagulant therapy may require dosage adjustments if barbiturates are added to or withdrawn

from their dosage regimen.

2. Corticosteroids. Barbiturates appear 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 barbiturates are 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 barbiturates on the metabolism of

phenytoin appears to be variable. Some investigators report an accelerating effect, whereas others

report no effect. Because the effect of barbiturates on the metabolism of phenytoin is not

predictable, phenytoin and barbiturate blood levels should be monitored more frequently if these

drugs are given concurrently. Sodium valproate and valproic acid increase the phenobarbital serum

levels; therefore, phenobarbital blood levels should be closely monitored and appropriate dosage

adjustments made as clinically indicated.

6. CNS Depressants. The concomitant use of other CNS 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 barbiturates, probably

because metabolism of the barbiturate 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

become pregnant while taking oral contraceptives. An alternate contraceptive method might be

suggested to women taking phenobarbital.

Carcinogenesis, Mutagenesis, Impairment of Fertility

1. Animal Data. Phenobarbital sodium is carcinogenic in mice and rats after lifetime administration. In

mice, it produced benign and malignant liver cell tumors. In rats, benign liver cell tumors were

observed very late in life.

2. Human Data. In a 29-year epidemiological study of 9,136 patients who were treated on an

anticonvulsant protocol that included phenobarbital, results indicated a higher than normal incidence

of hepatic carcinoma. Previously, some of these patients had been treated with thorotrast, a drug

which is known to produce hepatic carcinomas. Thus, this study did not provide sufficient evidence

that phenobarbital sodium is carcinogenic in humans.

A retrospective study of 84 children with brain tumors matched to 73 normal controls and 78 cancer

controls (malignant disease other than brain tumors) suggested an association between exposure to

barbiturates prenatally and an increased incidence of brain tumors.

Pregnancy

1. Teratogenic Effects

Pregnancy Category D – See Usage in Pregnancy under WARNINGS.

2. Nonteratogenic Effects

Reports of infants suffering from long-term barbiturate exposure in utero included the acute withdrawal

syndrome of seizures and hyperirritability from birth to a delayed onset of up to 14 days (see DRUG

ABUSE AND DEPENDENCE).

Labor and Delivery

Hypnotic doses of barbiturates do not appear to impair uterine activity significantly during labor. Full

anesthetic doses of barbiturates decrease the force and frequency of uterine contractions.

Administration of sedative-hypnotic barbiturates to the mother during labor may result in respiratory

depression in the newborn. Premature infants are particularly susceptible to the depressant effects of

barbiturates. If barbiturates are used during labor and delivery, resuscitation equipment should be

available.

Data are not available to evaluate the effect of barbiturates when forceps delivery or other intervention

is necessary or to determine the effect of barbiturates on the later growth, development, and functional

maturation of the child.

Nursing Mothers

Caution should be exercised when phenobarbital is administered to a nursing woman, because small

amounts of barbiturates are excreted in the milk.

ADVERSE REACTIONS

The following adverse reactions have been reported:

CNS Depression – Residual sedation or “hangover”, drowsiness, lethargy, and vertigo. Emotional

disturbances and phobias may be accentuated. In some persons, barbiturates such as phenobarbital

repeatedly produce excitement rather than depression, and the patient may appear to be inebriated.

Irritability and hyperactivity can occur in children. Like other nonanalgesic hypnotic drugs, barbiturates

such as phenobarbital, when given in the presence of pain, may cause restlessness, excitement, and even

delirium. Rarely, the use of barbiturates results in localized or diffuse myalgic, neuralgic, or arthritic

pain, especially in psychoneurotic patients with insomnia. The pain may appear in paroxysms, is most

intense in the early morning hours, and is most frequently located in the region of the neck, shoulder

girdle, and upper limbs. Symptoms may last for days after the drug is discontinued.

Respiratory/Circulatory – Respiratory depression, apnea, circulatory collapse.

Allergic – Acquired hypersensitivity to barbiturates consists chiefly in allergic reactions that occur

especially in persons who tend to have asthma, urticaria, angioedema, and similar conditions.

Hypersensitivity reactions in this category include localized swelling, particularly of the eyelids,

cheeks, or lips, and erythematous dermatitis. Rarely, exfoliative dermatitis (e.g., Stevens-Johnson

syndrome and toxic epidermal necrolysis) may be caused by phenobarbital and can prove fatal. The skin

eruption may be associated with fever, delirium, and marked degenerative changes in the liver and other

parenchymatous organs. In a few cases, megaloblastic anemia has been associated with the chronic use

of phenobarbital.

Other – Nausea and vomiting; headache, osteomalacia.

The following adverse reactions and their incidence were compiled from surveillance of thousands of

hospitalized patients who received barbiturates. Because such patients may be less aware of the milder

adverse effects of barbiturates, the incidence of these reactions may be somewhat higher in fully

ambulatory patients.

More than 1 in 100 Patients: The most common adverse reaction, estimated to occur at a rate of 1 to 3

patients per 100, is:

Nervous System: Somnolence

Less than 1 in 100 Patients: Adverse reactions estimated to occur at a rate of less than 1 in 100

patients are listed below, grouped by organ system and by decreasing order of occurrence:

Nervous System: Agitation, confusion, hyperkinesia, ataxia, CNS depression, nightmares, nervousness,

psychiatric disturbance, hallucinations, insomnia, anxiety, dizziness, abnormality in thinking

Respiratory System: Hypoventilation, apnea

Cardiovascular System: Bradycardia, hypotension, syncope

Digestive System: Nausea, vomiting, constipation

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

Controlled Substance

Phenobarbital is a Schedule IV drug.

Dependence

Barbiturates may be habit forming. Tolerance, psychological dependence, and physical dependence may

occur, especially following prolonged use of high doses of barbiturates. Daily administration in excess

of 400 mg of pentobarbital or secobarbital for approximately 90 days is likely to produce some degree

of physical dependence. A dosage of 600 to 800 mg taken for at least 35 days is sufficient to produce

withdrawal seizures. The average daily dose for the barbiturate addict is usually about 1.5 g. As

tolerance to barbiturates develops, the amount needed to maintain the same level of intoxication

increases; tolerance to a fatal dosage, however, does not increase more than twofold. As this occurs,

the margin between intoxicating dosage and fatal dosage becomes smaller.

Symptoms of acute intoxication with barbiturates include unsteady gait, slurred speech, and sustained

nystagmus. Mental signs of chronic intoxication include confusion, poor judgment, irritability, insomnia,

and somatic complaints.

Symptoms of barbiturate 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 barbiturate withdrawal can be severe and may cause death. Minor withdrawal

symptoms may appear 8 to 12 hours after the last dose of a barbiturate. 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 barbiturates. The intensity of withdrawal symptoms gradually declines over a period

of approximately 15 days. Individuals susceptible to barbiturate abuse and dependence include

alcoholics and opiate abusers as well as other sedative-hypnotic and amphetamine abusers.

Drug dependence on barbiturates arises from repeated administration of a barbiturate or agent with

barbiturate-like effect on a continuous basis, generally in amounts exceeding therapeutic dose levels.

The characteristics of drug dependence on barbiturates 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 barbiturate dependence consists of cautious and gradual withdrawal of the drug.

Barbiturate-dependent patients can be withdrawn by using a number of different withdrawal regimens. In

all cases, withdrawal requires an extended period of time. One method involves substituting a 30-mg

dose of phenobarbital for each 100- to 200-mg dose of barbiturate that the patient has been taking. The

total daily amount of phenobarbital is then administered in 3 or 4 divided doses, not to exceed 600 mg

daily. If 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/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% if tolerated by the patient.

Infants who are physically dependent on barbiturates may be given phenobarbital, 3 to 10 mg/kg/day.

After withdrawal symptoms (hyperactivity, disturbed sleep, tremors, and hyperreflexia) are relieved, the

dosage of phenobarbital should be gradually decreased and completely withdrawn over a 2-week

period.

OVERDOSAGE

Signs and Symptoms – The onset of symptoms following a toxic oral exposure to phenobarbital may not

occur until several hours following ingestion. The toxic dose of barbiturates varies considerably. In

general, an oral dose of 1 g of most barbiturates produces serious poisoning in an adult. Death

commonly occurs after 2 to 10 g of ingested barbiturate. The sedated, therapeutic blood levels of

phenobarbital range from 5 to 40 mcg/mL; the usual lethal blood level ranges from 100 to 200 mcg/mL.

Barbiturate intoxication may be confused with alcoholism, bromide intoxication, and various neurologic

disorders. Potential tolerance must be considered when evaluating significance of dose and plasma

concentration.

The manifestations of a long-acting barbiturate in overdose include nystagmus, ataxia, CNS depression,

respiratory depression, hypothermia, and hypotension. Other findings may include absent or depressed

reflexes and erythematous or hemorrhagic blisters (primarily at pressure points). Following massive

exposure to phenobarbital, pulmonary edema, circulatory collapse with loss of peripheral vascular

tone, cardiac arrest, and death may occur.

In extreme overdose, all electrical activity in the brain may cease, in which case a “flat” EEG normally

equated with clinical death should not be accepted. This effect is fully reversible unless hypoxic

damage occurs.

Consideration should be given to the possibility of barbiturate intoxication even in situations that appear

to involve trauma.

Complications such as pneumonia, pulmonary edema, cardiac arrhythmias, congestive heart failure, and

renal failure may occur. Uremia may increase CNS sensitivity to barbiturates if renal function is

impaired. Differential diagnosis should include hypoglycemia, head trauma, cerebrovascular accidents,

convulsive states, and diabetic coma.

Treatment – To obtain up-to-date information about the treatment of overdose, a good resource is your

certified Regional Poison Control Center. Telephone numbers of certified poison control centers are

listed in the Physicians’ Desk Reference (PDR). In managing overdosage, consider the possibility of

multiple drug overdoses, interaction among drugs, and unusual drug kinetics in your patient.

Protect the patient’s airway and support ventilation and perfusion. Meticulously monitor and maintain,

within acceptable limits, the patient’s vital signs, blood gases, serum electrolytes, etc. Absorption of

drugs from the gastrointestinal tract may be decreased by giving activated charcoal, which, in many

cases, is more effective than emesis or lavage; consider charcoal instead of or in addition to gastric

emptying. Repeated doses of charcoal over time may hasten elimination of some drugs that have been

absorbed. Safeguard the patient’s airway when employing gastric emptying or charcoal.

Alkalinization of urine hastens phenobarbital excretion, but dialysis and hemoperfusion are more

effective and cause less troublesome alterations in electrolyte equilibrium. If the patient has chronically

abused sedatives, withdrawal reactions may be manifest following acute overdose.

DOSAGE AND ADMINISTRATION

The dose of phenobarbital must be individualized with full knowledge of its particular characteristics.

Factors of consideration are the patient’s age, weight, and condition.

Sedation:

For sedation, the drug may be administered in single dose of 30 to 120 mg repeated at intervals:

frequency will be determined by the patient’s response. It is generally considered that no more than 400

mg of phenobarbital should be administered during a 24-hour period.

Adults:

Daytime Sedation: 30 to 120 mg daily in 2 to 3 divided doses.

Oral Hypnotic: 100 to 200 mg.

Anticonvulsant Use – Clinical laboratory reference values should be used to determine the therapeutic

anticonvulsant level of phenobarbital in the serum. To achieve the blood levels considered therapeutic

in pediatric patients, higher per-kilogram dosages are generally necessary for phenobarbital and most

other anticonvulsants. In children and infants, phenobarbital at a loading dose of 15 to 20 mg/kg

produces blood levels of about 20 mcg/mL shortly after administration.

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.

Adults: 60 to 200 mg/day.

Pediatric Patients: 3 to 6 mg/kg/day.

Special Patient Population – Dosage should be reduced in the elderly or debilitated because these

patients may be more sensitive to barbiturates. Dosage should be reduced for patients with impaired

renal function or hepatic disease.

HOW SUPPLIED

Phenobarbital Tablets, USP 16.2 mg: White, round, tablets scored on one side and debossed “e5"

above the score and "110” below the score. The other side is plain. Available in bottles of 100 tablets,

NDC 13517-110-01, 1000 tablets, NDC 13517-110-10, 30 tablets in blister pack NDC 58118-1110-8

Phenobarbital Tablets, USP 32.4 mg: White, round, tablets scored on one side and debossed “e5"

above the score and "111” below the score. The other side is plain. Available in bottles of 100 tablets,

NDC 13517-111-01 and 1000 tablets, NDC 13517-111-10.

Phenobarbital Tablets, USP 64.8 mg: White, round, tablets scored on one side and debossed “e5"

above the score and "112” below the score. The other side is plain. Available in bottles of 100 tablets,

NDC 13517-112-01 and 1000 tablets, NDC 13517-112-10.

Phenobarbital Tablets, USP 97.2 mg: White, round, tablets scored on one side and debossed “e5"

above the score and "113” below the score. The other side is plain. Available in bottles of 100 tablets,

NDC 13517-113-01 and 1000 tablets, NDC 13517-113-10.

Storage and Handling

Store at 20°- 25°C (68°- 77°F) [See USP Controlled Room Temperature]. Protect from light and

moisture.

Dispense in a tight, light-resistant container as defined in the USP using a child-resistant closure.

Manufactured for:

e5 Pharma, LLC

Boca Raton, FL 33432

Repackaged By:

Clinical Solutions Wholesale

Franklin, TN 37067

PRINCIPAL DISPLAY PANEL

Phenobarbital Tablets, USP 16.2 mg container label

PHENOBARBITAL

phenobarbital tablet

Product Information

Product T ype

HUMAN PRESCRIPTION

DRUG

Ite m Code (Source )

NDC:58 118 -

1110 (NDC:13517-110 )

Route of Administration

ORAL

DEA Sche dule

Active Ingredient/Active Moiety

Ingredient Name

Basis of Strength

Stre ng th

PHENO BARBITAL (UNII: YQE40 3BP4D) (PHENOBARBITAL - UNII:YQE40 3BP4D)

PHENOBARBITAL

16 .2 mg

Inactive Ingredients

Ingredient Name

Stre ng th

ANHYDRO US LACTO SE (UNII: 3SY5LH9 PMK)

MICRO CRYSTALLINE CELLULO SE (UNII: OP1R32D6 1U)

MAGNESIUM STEARATE (UNII: 70 0 9 7M6 I30 )

SILICO N DIO XIDE (UNII: ETJ7Z6 XBU4)

SO DIUM STARCH GLYCO LATE TYPE A PO TATO (UNII: 58 56 J3G2A2)

STEARIC ACID (UNII: 4ELV7Z6 5AP)

Product Characteristics

Color

white

S core

2 pieces

S hap e

ROUND

S iz e

6 mm

Flavor

Imprint Code

e 5;110

Contains

Packag ing

#

Item Code

Package Description

Marketing Start Date

Marketing End Date

1

NDC:58 118 -1110 -8

30 in 1 BLISTER PACK; Type 0 : No t a Co mbinatio n Pro duct

0 8 /13/20 19

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