Skip to content
ppharmaranks
Menu

sezaby

Sezaby (Phenobarbital Sodium) is a medication used to treat Febrile Seizures, Partial Epilepsies, Tonic-Clonic Epilepsy, Hyperbilirubinemia.

Phenobarbital Sodium · by Sun Pharm Inds Inc

Not yet rated· sourced from the FDA label
Rated against independent regulatory sources·Last updated June 7, 2026·How we rate
Verified againstopenFDANIH DailyMedRxClass
Lower-cost optionsSave up to 33%
This medication~$3.49/30
Cheapest in class · keppra~$2.34/30
See FDA-approved alternatives

Key facts

Active ingredient
Phenobarbital Sodium
Form
Injectable
Strength
Phenobarbital Sodium 100MG/VIAL
Type
Prescription (Rx)
Brand or generic
Brand-name
Manufacturer
Sun Pharm Inds Inc
What the pharmacy pays
~$3.49 for 30 — not your price
FDA application
NDA215910

What is Sezaby?

From the FDA label:Phenobarbital is a barbiturate. Chemically, phenobarbital sodium is 2,4,6(1H,3H,5H)-Pyrimidinetrione, 5-ethyl-5-phenyl-, monosodium salt and has the following structural formula: C 12 H 11 N 2 NaO 3 MW 254.22 The sodium salt of phenobarbital occurs as a white, slightly bitter powder, crystalline granules or flaky crystals; it is very soluble in water, soluble in alcohol and practically insoluble in ether or chloroform. SEZABY (phenobarbital sodium) for injection, for intravenous use, is supplied as sterile white to off white lyophilized powder in a 10 mL tubular glass vial. Each single-dose vial contains 100 mg of phenobarbital sodium, USP (equivalent to 91.35 mg of phenobarbital). The pH range is 9.20-10.00. SEZABY does not contain benzyl alcohol or propylene glycol. sezaby-1

How to use

Loading Dose: 20 mg/kg is administered by intravenous infusion over 15 minutes into a large peripheral vein. If clinically indicated, at least 15 minutes after completion of the initial loading dose, a second loading dose may be administered over the subsequent 15 minutes as 20 mg/kg for term infants or 10 mg/kg or 20 mg/kg for preterm infants. The maximum total loading dose is 40 mg/kg. (2.1) Maintenance Dosage: starting 8 to 12 hours after first loading dose: 4.5 mg/kg/day given in 2 or 3 divided doses (i.e., 1.5 mg/kg every 8 hours or 2.25 mg/kg every 12 hours) up to 5 days. (2.1). Must be reconstituted with 10 mL 0.9 % Sodium Chloride Injection, USP prior to administration. See additional preparation and administration instructions in the Full Prescribing Information. (2.3) 2.1 Recommended Dosage and Administration The recommended dosage of SEZABY in neonates consists of a loading dose(s) followed by maintenance dosage (see Table 1). Administer SEZABY by intravenous infusion (over 15 minutes) into a large peripheral vein to avoid local tissue toxicity [see Warnings and Precautions (5.9)]. SEZABY is for intravenous use only. Table 1: Recommended Dosage of SEZABY for Neonatal Seizures Loading Dose (maximum total loading dose is 40 mg/kg) First loading dose 20 mg/kg Second loading dose (If clinically indicated) 1 Preterm Infants 10 mg/kg or 20 mg/kg [see Clinical Pharmacology…

Side effects

The following clinically significant adverse reactions are described elsewhere in the labeling: Risks from Concomitant Use with Opioids [see Warnings and Precautions (5.1)] Dependence and Withdrawal Reactions After Use of SEZABY for a Longer Duration Than Recommended [see Warnings and Precautions (5.2)] Abuse, Misuse, and Addiction with Unapproved Use in Adolescents and Adults [see Warnings and Precautions (5.3)] Respiratory Depression or Insufficiency [see Warnings and Precautions (5.4)] Serious Dermatologic Reactions [see Warnings and Precautions (5.5)] Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)/Multiorgan Hypersensitivity [see Warnings and Precautions (5.6)] Hypersensitivity [see Warnings and Precautions (5.7)] Exacerbation of Porphyria [see Warnings and Precautions (5.8)] Injection Site Reactions [see Warnings and Precautions (5.9)] QT Prolongation [see Warnings and Precautions (5.10)] Embryofetal Toxicity with Unapproved Use in Adolescents and Adults [see Warnings and Precautions (5.11)] Neonatal Adverse Reactions from Unapproved Maternal Phenobarbital Use [see Warnings and Precautions (5.12)] Sedation, Respiratory Depression, and Withdrawal in Neonates Exposed to Phenobarbital Through Breast Milk [see Warnings and Precautions (5.13)] Suicidal Behavior and Ideation with Unapproved use in Adolescents and Adults [see Warnings and Precautions (5.14)] The…

FDA Boxed Warning (the FDA’s most serious warning)

Boxed (black-box) warning — from the FDA label

RISKS FROM CONCOMITANT USE WITH OPIOIDS; DEPENDENCE AND WITHDRAWAL REACTIONS AFTER USE OF SEZABY FOR A LONGER DURATION THAN RECOMMENDED; and ABUSE, MISUSE AND ADDICTION WITH UNAPPROVED USE IN ADOLESCENTS AND ADULTS Risks from Concomitant Use with Opioids Concomitant use of phenobarbital products, including SEZABY, and opioids may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of these drugs for patients for whom alternative treatment options are inadequate. If a decision is made for concomitant use of these drugs, limit dosages and durations to the minimum required, and follow patients for signs and symptoms of respiratory depression and sedation [see Warnings and Precautions (5.1) and Drug Interactions (7.3)]. Dependence and Withdrawal Reactions After Use of SEZABY for a Longer Duration than Recommended The continued use of phenobarbital may lead to clinically significant physical dependence. The risks of dependence and withdrawal increase with longer treatment duration and higher daily dose. Although SEZABY is indicated only for short-term use [see Indications and Usage (1) and Dosage and Administration (2)], if used for a longer duration than recommended, abrupt discontinuation or rapid dosage reduction of SEZABY may precipitate acute withdrawal reactions, which can be life-threatening. For patients receiving SEZABY for longer duration than recommended, to reduce the risk of withdrawal reactions, use a gradual taper to discontinue SEZABY [see Warnings and Precautions (5.2)]. Abuse, Misuse, and Addiction with Unapproved Use in Adolescents and Adults SEZABY is not approved for use in adolescents or adults. The unapproved use of SEZABY, in adolescents and adults exposes them to risks of abuse, misuse, and addiction, which can lead to overdose or death. Abuse and misuse of phenobarbital commonly involve concomitant use of other drugs, alcohol, and/or illicit substances, which is associated with an increased frequency of serious adverse outcomes [see Warnings and Precaution (5.3)]. WARNING: RISKS FROM CONCOMITANT USE WITH OPIOIDS; DEPENDENCE AND WITHDRAWAL REACTIONS AFTER USE OF SEZABY FOR A LONGER DURATION THAN RECOMMENDED; and ABUSE, MISUSE, AND ADDICTION WITH UNAPPROVED USE IN ADOLESCENTS AND ADULTS See full prescribing information for complete boxed warning . Concomitant use of phenobarbital products, including SEZABY, and opioids may result in profound sedation, respiratory depression, coma, and death. If a decision is made to use concomitantly, limit dosages and durations to the minimum required, and monitor patients for respiratory depression and sedation. (5.1, 7.3) Although SEZABY is indicated only for short-term use (1, 2), if used for a longer duration than recommended, abrupt discontinuation or rapid dosage reduction may precipitate acute withdrawal reactions, which can be life-threatening. For patients receiving SEZABY for a longer duration than recommended, to reduce the risk of withdrawal reactions, use a gradual taper to discontinue SEZABY. (5.2) SEZABY is not approved for use in adolescents or adults. The unapproved use of SEZABY in adolescents and adults exposes them to risks of abuse, misuse, and addiction, which can lead to overdose or death. (5.3)

Warnings

Important safety information

Respiratory Depression or Insufficiency: Abnormal respiration has been observed; careful respiratory monitoring is recommended during and after treatment. (5.4) Serious Dermatologic Reactions: Serious and sometimes fatal hypersensitivity reactions, including toxic epidermal necrolysis and Stevens-Johnson syndrome, have been reported. SEZABY should be discontinued at the first sign of a rash, unless the rash is clearly not drug related. (5.5) Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)/Multiorgan hypersensitivity : DRESS can be fatal or life-threatening. If signs or symptoms of DRESS are present, evaluate the patient immediately. Discontinue if an alternative etiology cannot be established. (5.6) Infusion Site Reactions : SEZABY may cause tissue damage with necrosis; avoid perivascular extravasation or intra-arterial injection. Stop SEZABY if evidence of pain, swelling, discoloration, or temperature change in limb. (5.9) QT Prolongation : Avoid concomitant use of SEZABY in patients who are at significant risk of developing torsade de pointes and with products that may increase the risk of the QTc interval prolongation or products that may increase concentrations of SEZABY. (5.10) 5.1 Risks from Concomitant Use with Opioids Concomitant use of phenobarbital products, including SEZABY, and opioids may result in profound sedation, respiratory depression, coma, and death [see Drug Interactions (7.3)] . Reserve concomitant prescribing of these drugs for patients for whom alternative treatment options are inadequate. If a decision is made for concomitant use of these drugs, limit dosages and durations to the minimum required, and follow patients for signs and symptoms of respiratory depression and sedation. Practitioners administering SEZABY must have the skills necessary to manage serious cardiorespiratory adverse reactions, including skills in airway management. 5.2 Dependence and Withdrawal Reactions After Use of SEZABY for a Longer Duration Than Recommended The continued use of phenobarbital may lead to clinically significant physical dependence. Although SEZABY is indicated only for short-term use [see Indications and Usage (1) and Dosage and Administration (2)] , if used for a longer duration than recommended, abrupt discontinuation or rapid dosage reduction of SEZABY may precipitate acute withdrawal reactions, which can be life-threatening (e.g., seizures) [see Drug Abuse and Dependence (9.3)] . To reduce the risk of withdrawal reactions in patients receiving SEZABY for a longer duration than recommended, use a gradual taper to discontinue SEZABY (a patient-specific plan should be used to taper the dose). Patients at an increased risk of withdrawal adverse reactions after phenobarbital discontinuation or rapid dosage reduction include those who received higher dosages, or those who had longer durations of use. 5.3 Abuse, Misuse, and Addiction with Unapproved Use in Adolescents and Adults SEZABY is not approved for use in adolescents or adults. The unapproved use of SEZABY in adolescents and adults exposes them to the risks of abuse, misuse, and addiction, which can lead to overdose or death. Abuse and misuse of barbiturates, including phenobarbital, often (but not always) involve the use of doses exceeding the doses used in clinical practice and commonly involve concomitant use of other drugs, alcohol, and/or illicit substances, which is associated with an increased frequency of serious adverse outcomes, including respiratory depression, overdose, or death [see Drug Abuse and Dependence (9.2)] . 5.4 Respiratory Depression or Insufficiency In Study 1, 25% of patients treated with phenobarbital developed abnormal respiration [see Adverse Reactions (6.1) and Clinical Studies (14)] . Careful respiratory monitoring is needed during and after the administration of SEZABY. 5.5 Serious Dermatologic Reactions Serious and sometimes fatal dermatologic reactions, including toxic epidermal necrolysis (TEN) and Stevens-Johnson syndrome (SJS), have been reported with the use of phenobarbital. SEZABY should be discontinued at the first sign of a rash, unless the rash is clearly not drug related. If signs or symptoms suggest SJS/TEN, use of SEZABY should not be resumed and alternative therapy should be considered. If a rash occurs, the patient should be evaluated for signs and symptoms of Drug Reaction with Eosinophilia and Systemic Symptoms [see Warnings and Precautions (5.6)] . 5.6 Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)/Multiorgan Hypersensitivity Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS), also known as multiorgan hypersensitivity, has been reported in patients taking antiepileptic drugs, including phenobarbital. Some of these events have been fatal or life-threatening. DRESS typically, although not exclusively, presents with fever, rash, lymphadenopathy, and/or facial swelling, in association with other organ system involvement, such as hepatitis, nephritis, hematological abnormalities, myocarditis, or myositis sometimes resembling an acute viral infection. Eosinophilia is often present. Because this disorder is variable in its expression, other organ systems not noted here may be involved. It is important to note that early manifestations of hypersensitivity, such as fever or lymphadenopathy, may be present even though rash is not evident. If such signs or symptoms are present, the patient should be evaluated immediately. SEZABY should be discontinued if an alternative etiology for the signs or symptoms cannot be established. 5.7 Hypersensitivity Reactions Phenobarbital-associated hypersensitivity reactions may include symptoms and signs such as rash, fever, facial or limb edema, and lymphadenopathy. SEZABY is contraindicated in patients who have experienced hypersensitivity to phenobarbital or other barbiturates. Additionally, consider alternatives to structurally similar drugs such as carboxamides (e.g., carbamazepine) and hydantoins (e.g., phenytoin) in these same patients. Similarly, if there is a history of hypersensitivity reactions to these structurally similar drugs in the patient or immediate family members, consider alternatives to SEZABY. If signs or symptoms of hypersensitivity reactions are present in a patient treated with SEZABY, the patient should be evaluated immediately and SEZABY should be discontinued if an alternative etiology for the signs or symptoms cannot be established. 5.8 Exacerbation of Porphyria SEZABY may precipitate acute attacks in patients with acute porphyrias. These episodes may be life-threatening, and include symptoms and signs such as anxiety, confusion, limb or abdominal pain, hyponatremia, seizures, and muscle weakness. Therefore, SEZABY is contraindicated in patients with acute porphyrias [see Contraindications (4)] . 5.9 Infusion Site Reactions SEZABY is highly alkaline [see Description (11)] . Therefore, extreme care should be taken to avoid perivascular extravasation or intra-arterial injection. Extravascular injection may cause local tissue damage with subsequent necrosis; consequences of intraarterial injection may vary from transient pain to gangrene of the limb. Any evidence of pain, swelling, discoloration, or temperature change in the limb warrants stopping the injection. 5.10 QT Prolongation SEZABY may prolong the QT interval [see Clinical Pharmacology (12.2)] . Avoid use of SEZABY in patients who are at significant risk of developing torsade de pointes, including those with congenital long QT syndrome, uncontrolled or significant cardiac disease, recent myocardial infarction, heart failure, unstable angina, bradyarrhythmias, AV block, aortic stenosis, or uncontrolled hypothyroidism. If use cannot be avoided in these patients, collect ECGs during treatment at specified intervals as clinically indicated, and monitor serum electrolytes and correct abnormalities. Avoid the concomitant use of products that may increase the risk of QTc interval…

Who should not take Sezaby

SEZABY is contraindicated in patients with: acute porphyrias [see Warnings and Precautions (5.8)], or a history of hypersensitivity reaction to phenobarbital or other barbiturates [see Warnings and Precautions (5.7)] Acute porphyrias (4) Hypersensitivity to phenobarbital or other barbiturates (4)

Overdose — what happens if you take too much

Overdosage of barbiturates, including phenobarbital, is characterized by central nervous system depression ranging from drowsiness to coma. In mild to moderate cases, symptoms can include drowsiness, confusion, dysarthria, lethargy, hypnotic state, diminished reflexes, ataxia, and hypotonia. Rarely, paradoxical or disinhibitory reactions (including agitation, irritability, impulsivity, violent behavior, confusion, restlessness, excitement, and talkativeness) may occur. In severe overdosage cases, patients may develop respiratory depression and coma. Overdosage of barbiturates, particularly in combination with other CNS depressants (including alcohol and opioids) may be fatal [see Warnings and Precautions (5.3)] . Markedly elevated blood pressure, heart rate, or respiratory rate raise the concern that additional drugs are involved in the overdosage. In managing SEZABY overdosage, employ general supportive measures, including intravenous fluids, pressors, and airway maintenance. Consider contacting a poison center (1-800-221-2222) or a medical toxicologist for additional overdosage management recommendations.

U.S. Poison Control: call or text 1-800-222-1222 (free, 24/7). In an emergency call 911. From the FDA label; not medical advice.

Interactions

Inhibitors: Closely monitor and decrease SEZABY dosage, if needed. (7.1) CYP3A4, 2B6, 2C, UGT Substrates: Substrate dosage adjustment may be needed. (7.1) CNS depressants: Closely monitor for sedation and respiratory depression. (7.2) Drugs that Prolong the QT Interval : Avoid concomitant use. (7.3) 7.1 Cytochrome P450- or Uridine 5’-diphospho-glucuronosyltransferase (UGT)-Based Interactions The drug interaction information in Table 3 is based upon published literature in non-neonatal populations, in vitro studies, and the mechanistic knowledge of phenobarbital metabolic pathways [see Clinical Pharmacology (12.3)] . Although the data from the published literature regarding these drug interactions are from non-neonatal populations and the magnitude of the potential drug interactions in neonates have not been characterized, this information still warrants consideration given the potential impact of these possible drug interactions on the safety and efficacy of phenobarbital and CYP2B6, 2C9, 2C19, or UGT substrates in neonates. Table 3: Drug Interactions with SEZABY Effects of Other Drugs on SEZABY CYP2C9, 2C19, 2E1, Uridine 5'-diphospho-glucuronosyltransferases ( UGT) Inhibitors or Inducers Prevention or Management Closely monitor for adverse reactions (e.g., over sedation, prolonged QTc interval, etc.) when used concomitantly with inhibitors of these enzymes and reduced efficacy (e.g., breakthrough seizure) when used with inducers of these enzymes. Consider titration of the SEZABY maintenance dosage accordingly if concomitant use is unavoidable. Clinical Effect(s) Phenobarbital is a substrate of CYP2C9, CYP2C19, CYP2E1, and UGTs [see Clinical Pharmacology (12.3)] . It is likely that concomitant use will result in an increase in phenobarbital exposure when used with these inhibitors and a reduction when used with these inducers, which may increase the risk of SEZABY adverse reactions or reduce efficacy, respectively when concomitant use in neonates. Effects of Other Drugs on Sezaby CYP3A, 2B6, 2C(s), UGTs Substrates Prevention or Management Closely monitor neonates when SEZABY is used concurrently with substrates of these enzymes and consider increasing the dosage of the substrate accordingly, unless otherwise advised in its Prescribing Information, if concomitant use is unavoidable. Clinical Effect(s) Phenobarbital is an inducer of CYP3A, CYP2B6, CYP2C(s), and UGT(s) [see Clinical Pharmacology (12.3)] . It is likely that concomitant use in neonates will result in a decrease in the exposure of these substrates, which may reduce efficacy. 7.2 CNS Depressants Closely monitor for signs of sedation and respiratory depression with concomitant use of SEZABY with other CNS depressants, including opioids [see Warnings and Precautions (5.1)] . Phenobarbital may cause sedation and respiratory depression [see Warnings and Precautions (5.4) and Adverse Reactions (6.1)] . Other products that may also cause these adverse reactions may have additive pharmacologic effect and may increase the risk of sedation and respiratory depression. 7.3 Drugs that Prolong QT Interval SEZABY may prolong the QT interval [see Warnings and Precautions (5.10) and Clinical Pharmacology (12.2)] . Other products that may also prolong the QTc interval may have additive effects, and products that may increase concentrations of phenobarbital [see Drug Interactions (7.1)] may increase the QT prolongation risk; therefore, avoid concomitant use of SEZABY and these products. If concomitant use of a product that also prolongs the QTc interval or that increases SEZABY concentrations is unavoidable, monitor patients for increased risk of QTc interval prolongation.

May treat (source: NIH RxClass)

Dosage forms

Injectable

The forms currently marketed in the U.S., per the FDA National Drug Code Directory.

Ways to save

Ask for the generic

Same active ingredient, far cheaper. Is there a generic? →

Request a 90-day supply

Bulk fills usually lower the per-dose price vs monthly refills.

Use copay cards

Manufacturer copay cards & patient-assistance programs — especially for brand drugs.

Compare alternatives

A same-class option may cost less. See alternatives →

Frequently asked questions

What does Sezaby treat?
Sezaby (Phenobarbital Sodium) may be used to treat febrile seizures, partial epilepsies, tonic-clonic epilepsy, hyperbilirubinemia, benign neonatal epilepsy, based on NIH RxClass drug-classification data (conditions a drug may treat — not a verbatim copy of the FDA-approved label). This is general reference, not medical advice.
How much does Sezaby cost?
Nobody can tell you what you will pay — your price is set by your insurer's formulary, your deductible and the pharmacy's markup, and none of those are published. What IS published is what the pharmacy paid to acquire it: about $3.49 for 30, per the CMS NADAC survey. Treat that as the floor, not the quote — ask the pharmacist for the cash price as well as your copay, because for cheap generics the cash price often wins. Pharmacies pay less for a same-class option, Keppra — about $2.34 on the same basis.
Is there a coupon or discount for Sezaby?
pharmaranks is an independent ratings site, not a pharmacy — we don't issue coupons or sell Sezaby. To pay less, ask your prescriber or pharmacist whether a generic equivalent exists, check the manufacturer's copay/savings card and patient-assistance program, and compare a pharmacy discount card against your insurance copay. Prices vary by pharmacy, insurance, and location, so always confirm at the counter. This is general reference, not medical or financial advice.
Who makes Sezaby?
Sezaby is marketed by Sun Pharm Inds Inc. You can see Sun Pharm Inds Inc's full profile, rating, and other products on pharmaranks.
Is Sezaby a brand-name or generic drug?
Sezaby is a brand-name product with the active ingredient Phenobarbital Sodium.
Is Sezaby available over the counter?
No. Sezaby is a prescription (Rx) medication in the US — you need a prescription from a licensed clinician (in person or via telehealth); it isn't sold over the counter. For some conditions there are OTC alternatives — ask your pharmacist.
What forms does Sezaby come in?
Sezaby is currently marketed as injectable, per the FDA's National Drug Code Directory.
Is Sezaby FDA-registered?
Sezaby is on record with the U.S. FDA under application number NDA215910. You can verify this on its official FDA label.
Is Sezaby safe?
There's no single safe-or-not verdict, and we don't yet have a composite recall-safety score for Sezaby. Review its FDA-label side effects and warnings below, and always consult a licensed professional.
What are the side effects of Sezaby?
Sezaby's side effects are taken directly from its FDA label. From the label: The following clinically significant adverse reactions are described elsewhere in the labeling: Risks from Concomitant Use with Opioids [see Warnings and Precautions (5.1)] Dependence and Withdrawal Reactions After Use of SEZABY for a Longer Duration Than Recommended [see Warnings and Precautions (5… Both common and serious reactions are documented in full on this page. This is general reference from the FDA, not medical advice — always consult a professional.

Clinical content sourced from the FDA label via openFDA (U.S. FDA). View the FDA label on DailyMed → Provided for general reference only — not medical advice. Always consult a licensed professional and the current prescribing information.

Reviews

No reviews yet. Be the first to write one.

Write a review

Reviews are user opinions, not medical advice. Consult a licensed professional.

People also viewed

Compare Sezaby head-to-head

Identify a pill by its imprint →Check a drug interaction →Drug recalls →

Browse medications A–Z

Research products from A to Z, compare independent ratings, and find alternatives.