Phenobarbital Sodium
Loading...Phenobarbital Sodium Recall
Get an alert when a recall is issued.
Questions & Answers
Side Effects & Adverse Reactions
Phenobarbital Sodium Injection contains the preservative benzyl alcohol and is not recommended for use in neonates. There have been reports of fatal ‘gasping syndrome’ in neonates (children less than one month of age) following the administration of intravenous solutions containing the preservative benzyl alcohol. Symptoms include a striking onset of gasping respiration, hypotension, bradycardia, and cardiovascular collapse.
Barbiturates may be habit forming. Tolerance and psychological and physical dependence may occur with continued use (see DRUG ABUSE AND DEPENDENCE and CLINICAL PHARMACOLOGY). Patients who are psychologically dependent on barbiturates may increase the dosage or decrease the dosage interval without consulting a physician and may subsequently develop a physical dependence on barbiturates. 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 the dependent person may result in withdrawal symptoms, including delirium, convulsions and possibly death. Barbiturates should be withdrawn gradually from any patient known to be taking excessive dosage over long periods of time (see DRUG ABUSE AND DEPENDENCE).
Exfoliative dermatitis and Stevens-Johnson syndrome, possibly fatal, are rare hypersensitivity reactions to phenobarbital. Physicians should be alert to signs which may precede the onset of barbiturate-induced cutaneous lesions, and the drug should be discontinued whenever dermatological reactions occur.
Too rapid administration may cause severe respiratory depression, apnea, laryngospasm, hypertension or vasodilation with fall in blood pressure.
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 brain levels to exceed that required to control the convulsions and lead to severe barbiturate-induced depression.
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.
Barbiturates can cause fetal harm 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. Phenobarbital may cause major fetal malformations.
Following oral or parenteral administration, barbiturates readily cross the placental barrier and are distributed throughout fetal tissues with highest concentrations 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 mothers who receive barbiturates throughout the last trimester of pregnancy (see DRUG ABUSE AND DEPENDENCE).
Phenobarbital should be used during pregnancy only when clearly indicated. If phenobarbital is used during pregnancy or if the patient becomes pregnant while taking the drug, the patient should be apprised of the potential hazard to the fetus.
Phenobarbital has been reported to be associated with cognitive defects in children taking it for complicated febrile seizures.
The concomitant use of alcohol or other CNS depressants may produce additive CNS depressant effects.
Legal Issues
There is currently no legal information available for this drug.
FDA Safety Alerts
There are currently no FDA safety alerts available for this drug.
Manufacturer Warnings
There is currently no manufacturer warning information available for this drug.
FDA Labeling Changes
There are currently no FDA labeling changes available for this drug.
Uses
- 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 (see CLINICAL PHARMACOLOGY).
- Preanesthetic.
- 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.
History
There is currently no drug history available for this drug.
Other Information
The barbiturates are nonselective central nervous system (CNS) depressants which are primarily used as sedative hypnotics and also anticonvulsants in subhypnotic doses. The barbiturates and their sodium salts are subject to control under the Federal Controlled Substances Act (CIV).
Barbiturates are substituted pyrimidine derivatives in which the basic structure common to these drugs is barbituric acid, a substance which has no central nervous system activity. CNS activity is obtained by substituting alkyl, alkenyl or aryl groups on the pyrimidine ring.
Phenobarbital Sodium Injection, USP is a sterile solution for intramuscular or slow intravenous administration as a long-acting barbiturate. Each mL contains phenobarbital sodium either 65 mg or 130 mg, alcohol 0.1 mL, propylene glycol 0.678 mL and benzyl alcohol 0.015 mL in Water for Injection; hydrochloric acid added, if needed, for pH adjustment. The pH range is 9.2-10.2.
Chemically, phenobarbital sodium is 2,4,6(1H,3H,5H)-Pyrimidinetrione,5-ethyl-5-phenyl-, monosodium salt and has the following structural formula:
C12H11N2NaO3 MW 254.22
The sodium salt of phenobarbital occurs as a white, slightly bitter powder, crystalline granules or flaky crystals; it is soluble in alcohol and practically insoluble in ether or chloroform.
Sources
Phenobarbital Sodium Manufacturers
-
West-ward Pharmaceutical Corp.
![Phenobarbital Sodium Injection [West-ward Pharmaceutical Corp.]](/wp-content/themes/bootstrap/assets/img/loading2.gif)
Phenobarbital Sodium | West-ward Pharmaceutical Corp.
Dosages of barbiturates must be individualized with full knowledge of their particular characteristics and recommended rates of administration. Factors to consider are the patient’s age, weight and condition.
Suggested doses of phenobarbital sodium for specific indications follow:
Pediatric DosageRecommended by the American Academy of Pediatrics (intended as a guide)
Preoperative Sedation: 1 to 3 mg/kg IM or IV
Anticonvulsion: 4 to 6 mg/kg/day for 7 to 10 days to blood level of 10 to 15 mcg/mL or 10 to 15 mg/kg/day IM or IV
Status Epilepticus: 15 to 20 mg/kg over 10 to 15 minutes IV
Adult Dosage(intended as a guide)
Daytime Sedation: 30 to 120 mg daily in 2 to 3 divided doses IM or IV
Bedtime Hypnosis: 100 to 320 mg IM or IV
Preoperative Sedation: IM only — 100 to 200 mg 60 to 90 minutes before surgery
Acute Convulsions: 20 to 320 mg IM or IV, repeated in 6 hours as necessary
Parenteral routes should be used only when oral administration is impossible or impractical.
Intramuscular injection of the sodium salts of barbiturates should be made deeply into a large muscle and a volume of 5 mL should not be exceeded at any one site because of possible tissue irritation. Injection into or near peripheral nerves may result in permanent neurological deficit. After intramuscular injection of a hypnotic dose, the patient’s vital signs should be monitored.
Subcutaneous administration is not recommended (see CONTRAINDICATIONS).
Intravenous AdministrationIntravenous injection is restricted to conditions in which other routes are not feasible, either because the patient is unconscious (as in cerebral hemorrhage, eclampsia or status epilepticus), or because the patient resists (as in delirium) or because prompt action is imperative. Slow IV injection is essential, and patients should be carefully observed during administration. This requires that blood pressure, respiration and cardiac function be maintained, vital signs be recorded and equipment for resuscitation and artificial ventilation be available. The rate of intravenous injection for adults should not exceed 60 mg/min for phenobarbital sodium.
When given intravenously, do not use small veins, such as those on the dorsum of the hand or wrist. Preference should be given to a larger vein to minimize the risk of irritation with the possibility of resultant thrombosis. Avoid administration into varicose veins because circulation there is retarded. Inadvertent injection into or adjacent to an artery has resulted in gangrene requiring amputation of an extremity or a portion thereof. Careful technique, including aspiration, is necessary to avoid inadvertent intraarterial injection. (See below.)
Treatment of Adverse Effects Due to Inadvertent Error in AdministrationExtravasation into subcutaneous tissues causes tissue irritation. This may vary from slight tenderness and redness to necrosis. Recommended treatment includes the application of moist heat and the injection of 0.5% procaine solution into the affected area.
Intraarterial injection of any barbiturate must be avoided. The accidental intraarterial injection of a small amount of the solution may cause spasm and severe pain along the course of the artery. The injection should be terminated if the patient complains of pain or if other indications of accidental intraarterial injection occur, such as a white hand with cyanosed skin or patches of discolored skin and delayed onset of hypnosis.
The consequences of intraarterial injection of phenobarbital can vary from transient pain to gangrene. It is not possible to formulate strict rules for management of such accidents. The following procedures have been suggested: 1) release of the tourniquet or restrictive garments to permit dilution of injected drug, 2) relief of arterial spasm by injecting 10 mL of a 1% procaine solution into the artery and, if considered necessary, brachial plexus block, 3) prevention of thrombosis by early anticoagulant therapy and 4) supportive treatment.
Anticonvulsant UseA therapeutic anticonvulsant level of phenobarbital in the 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 doses 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 a barbiturate (or other anticonvulsants) as rapidly as possible. When administered intravenously, phenobarbital sodium may require 15 minutes or more to attain peak concentrations in the brain. If phenobarbital sodium is injected continuously until the convulsions stop, the brain concentration will continue to rise and can eventually exceed that required to control the seizures. 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 PopulationDosage 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.
Parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.
Login To Your Free Account