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Phenobarbital

Phenobarbital is a barbiturate used as a sedative and to control seizures, with injectable products also used for insomnia, before surgery, and in emergencies, and one brand (Sezaby) used only for seizures in newborns.

Brand names SezabyFidoquel
Rx Schedule CIV Forms 3
Dr. Brian Staiger, PharmD, BCPS
Reviewed by Last reviewed Jul 10, 2026 Content updated Oct 2, 2026
🧬 Where this information comes from Click to expand

The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 83 clinical label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →

Phenobarbital at a glance The quick version — the full detail is in the Patient Information Guide below.
Dr. Brian Staiger, PharmD, BCPS
The Pharmacist’s Take By · Clinical pharmacist · Written

Phenobarbital is a barbiturate, on the market since about 1967 and available as a generic, that quiets the brain and spinal cord to sedate and control seizures. It is now usually a later choice for adult epilepsy but still a mainstay for seizures in newborns. Its main drawback is sedation, with drowsiness and a next-day hangover feeling common, and children can turn excitable or irritable instead of calm. The boxed warning is about opioids, which with phenobarbital can cause profound sedation, slowed breathing, coma and death, and alcohol adds to that danger. It is habit forming, so never stop it suddenly, since withdrawal can bring seizures and delirium.

Clinical pearls

  • Phenobarbital speeds up liver enzymes and can lower levels of many other medicines, so make sure every prescriber knows you take it.
  • Before adding a sleep aid, allergy medicine or any other sedating drug, check with your pharmacist, because the drowsiness and breathing effects stack.
  • A rash, blisters or peeling skin, or fever with facial swelling or swollen glands, needs a call to your doctor right away.
  • If you are or may become pregnant, tell your prescriber early, since barbiturates can harm the fetus and cause newborn withdrawal.
How we write & review this content — our editorial policy →
How you get itPrescription only
Comes asTablet, Injection, Oral solution
Earliest FDA record1967
Companies listing it with the FDA30
FDA label last updatedMar 12, 2026
FDA’s strongest warning (boxed)None on the label

Patient information guide A plain-language walkthrough of Phenobarbital, written from its FDA label.

What Phenobarbital is used for

▾

Phenobarbital is used for sedation and seizure control, with some uses specific to certain products.

  • Phenobarbital tablets and oral solutions: sedative and treatment of generalized and partial seizures.
  • Phenobarbital Sodium injection: sedation, including for conditions like anxiety-tension states.
  • Phenobarbital Sodium injection: short-term treatment of insomnia, since it loses effectiveness for sleep after about 2 weeks.
  • Phenobarbital Sodium injection: sedation before surgery.
  • Phenobarbital Sodium injection: long-term seizure control and emergency control of acute convulsions such as status epilepticus, eclampsia and tetanus.
  • Phenobarbital Sodium injection: use in children as an anticonvulsant and sedative.
  • Sezaby (intravenous): neonatal seizures in term and preterm infants only.

How Phenobarbital works

▾

Phenobarbital depresses the central nervous system. It reduces activity in the sensory cortex, lowers motor activity and causes drowsiness, sedation and sleep.

Its anti-seizure action is selective and does not depend on how sedated you are. It limits the spread of seizures and raises the seizure threshold in generalized tonic-clonic (grand mal) epilepsy.

Phenobarbital dosage

▾

Tablets and oral solutions are taken by mouth. The dose is individualized by age, weight and condition. For sedation, adults often take it 2 to 3 times a day, and the label notes no more than 400 mg in 24 hours is generally advised.

  • Injections are given by a healthcare professional into a muscle or vein.
  • Sezaby is given by IV infusion to newborns, with a starting dose followed by maintenance doses for up to 5 days.
  • Blood levels may be checked when it is used for seizures.

Follow your prescriber and label directions, and do not stop suddenly.

Dosing details from the FDA-approved label

From the Phenobarbital prescribing information (“Dosage and Administration”). Doses are set by your prescriber for your product, condition, kidney function and age — never change a dose on your own.

  • Neonatal seizures (Sezaby) - first loading dose
    • 20 mg/kg by intravenous infusion over 15 minutes into a large peripheral vein
    • Maximum: Maximum total loading dose is 40 mg/kg
  • Neonatal seizures (Sezaby) - second loading dose, term infants (if clinically indicated)
    • 20 mg/kg, no sooner than 15 minutes after completion of the first loading dose
    • Maximum: Maximum total loading dose is 40 mg/kg
    • Term infants
  • Neonatal seizures (Sezaby) - second loading dose, preterm infants (if clinically indicated)
    • 10 mg/kg or 20 mg/kg, no sooner than 15 minutes after completion of the first loading dose
    • Maximum: Maximum total loading dose is 40 mg/kg
    • Preterm infants
  • Neonatal seizures (Sezaby) - maintenance dosage
    • 4.5 mg/kg/day in 2 or 3 divided doses (1.5 mg/kg every 8 hours or 2.25 mg/kg every 12 hours), starting 8 to 12 hours after first loading dose, for up to 5 days
    • Maximum: Total daily dose is 4.5 mg/kg/day; total duration up to 5 days
  • Pediatric preoperative sedation (phenobarbital sodium injection)
    • 1 to 3 mg/kg intramuscular or intravenous
  • Pediatric anticonvulsion (phenobarbital sodium injection)
    • 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 intramuscular or intravenous
  • Pediatric status epilepticus (phenobarbital sodium injection)
    • 15 to 20 mg/kg over 10 to 15 minutes intravenous
  • Adult daytime sedation
    • 30 to 120 mg daily in 2 to 3 divided doses intramuscular or intravenous
    • Reduce dosage in the elderly, debilitated, or with impaired renal or hepatic function
  • Adult bedtime hypnosis
    • 100 to 320 mg intramuscular or intravenous
  • Adult preoperative sedation
    • 100 to 200 mg intramuscular only, 60 to 90 minutes before surgery
Read the label’s full dosing text

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. 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 (eg, 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.

Excerpted — the section continues on the label. Read the full Dosage and Administration section on DailyMed →

Phenobarbital side effects

▾

Many side effects relate to slowing of the nervous system.

Common side effects

  • Drowsiness and sluggishness
  • Next-day “hangover” feeling or dizziness (vertigo)
  • Excitement or irritability instead of calm (especially in children)
  • Restlessness or confusion, especially when in pain
  • In newborns given Sezaby: abnormal breathing, sedation, feeding problems and low blood pressure
  • Drowsiness, lethargy and dizziness
  • Excitement, irritability or hyperactivity in some people, especially children

When to get medical help

  • Call for help right away for slowed or troubled breathing, extreme sleepiness, or inability to wake up, especially if you also take opioids or alcohol.
  • Stop and call your doctor right away for a rash, blisters or peeling skin, which can signal a serious, sometimes fatal skin reaction.
  • Seek care for fever, facial swelling or swollen glands, which can signal a serious multiorgan allergic reaction (DRESS).
  • Get urgent help for severe symptoms after stopping suddenly, such as delirium or seizures.
  • Report pain, swelling, discoloration or temperature change near an injection site.
  • Seek care for a fast or irregular heartbeat or fainting; Sezaby may prolong the QT interval (a heart rhythm change).

Seek help for slowed breathing, skin rash or blisters, fever with swelling, or withdrawal symptoms such as seizures.

Phenobarbital warnings and precautions

▾
  • Opioids and other sedating drugs: combining them can cause profound sedation, slowed breathing, coma and death.
  • Dependence: phenobarbital can be habit forming, and stopping suddenly after long use can cause delirium, convulsions and possibly death.
  • Breathing: it can depress breathing, so monitoring is needed, especially for Sezaby.
  • Skin and allergic reactions: serious reactions such as Stevens-Johnson syndrome, toxic epidermal necrolysis and DRESS have been reported.
  • Injection site damage: leakage outside a vein or injection into an artery can cause tissue death.
  • QT prolongation: Sezaby may affect heart rhythm.
  • Pregnancy: it can cause fetal harm and newborn withdrawal.

Phenobarbital interactions

▾

Phenobarbital can clash with several types of medicines.

  • Opioids: risk of profound sedation, slowed breathing and death.
  • Alcohol and other CNS depressants: additive sedation.
  • Drugs that prolong the QT interval: added heart rhythm risk with Sezaby.
  • Drugs processed by certain liver enzymes (such as CYP3A4, CYP2B6 and CYP2C): phenobarbital can lower their levels, so dose changes may be needed.
  • Drugs that block or boost those same enzymes can raise or lower phenobarbital levels.

Interactions listed in the FDA-approved label

From the Phenobarbital prescribing information (“Drug Interactions”): what the manufacturer studied or reported to the FDA.

  • CYP2C9, 2C19, 2E1, UGT inhibitors: Likely increases phenobarbital exposure, which may increase the risk of adverse reactions. Closely monitor for adverse reactions (e.g., over sedation, prolonged QTc interval) and consider titrating the SEZABY maintenance dosage if concomitant use is unavoidable.
  • CYP2C9, 2C19, 2E1, UGT inducers: Likely reduces phenobarbital exposure, which may reduce efficacy (e.g., breakthrough seizure). Monitor for reduced efficacy and consider titrating the SEZABY maintenance dosage if concomitant use is unavoidable.
  • CYP3A, 2B6, 2C(s), UGT substrates: Phenobarbital is an inducer of these enzymes and is likely to decrease exposure to these substrates, which may reduce efficacy. Closely monitor neonates and consider increasing the substrate dosage, unless otherwise advised in its Prescribing Information, if concomitant use is unavoidable.
  • CNS depressants, including opioids: Additive pharmacologic effect may increase the risk of sedation and respiratory depression. Closely monitor for signs of sedation and respiratory depression.
  • Drugs that prolong the QT interval: Additive QTc prolongation effects; products that increase phenobarbital concentrations may increase the QT prolongation risk. Avoid concomitant use; if unavoidable, monitor patients for increased risk of QTc interval prolongation.
Read the label’s full interactions text

Drug Interactions Most reports of clinically significant drug interactions occurring with the barbiturates have involved Phenobarbital. However, the application of this 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., warfarin, acenocoumarol, 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 absorptions 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.

Excerpted — the section continues on the label. Read the full Drug Interactions section on DailyMed →

Not a complete list. The label covers the interactions the manufacturer studied or reported, and our own interaction database does not cover every medicine either. Bring your full medication list, including vitamins and herbal products, to your pharmacist.

🌿174 supplements and herbs with documented Phenobarbital interactions, ranked by severity Check Phenobarbital against a supplement or herb →

Before taking Phenobarbital

▾
  • Do not use if you have known barbiturate sensitivity.
  • Do not use with porphyria, marked liver impairment, or severe breathing difficulty.
  • Avoid in people with a past addiction to sedative-hypnotic drugs.
  • Large doses should be avoided in people with nephritis (kidney inflammation).
  • Pregnancy: can cause fetal damage and newborn withdrawal.
  • Breastfeeding: passes into breast milk and may sedate infants.
  • Children: cognitive deficits have been reported in children taking it for complicated febrile seizures.
  • Tell your doctor if you have acute or chronic pain.

Phenobarbital overdose

▾

Too much phenobarbital can cause serious poisoning, with slowed breathing, low blood pressure, low body temperature, unsteadiness and deep CNS depression. Symptoms may not appear for several hours after swallowing it. Contact a Poison Control Center or emergency services immediately; treatment focuses on protecting the airway and supporting breathing and circulation.

What Phenobarbital does in the body

▾

Phenobarbital can produce effects from mild sedation to sleep, and at high enough doses anesthesia. It depresses breathing in a dose-dependent way. It reduces REM (dream) sleep, so stopping suddenly can cause vivid dreams, nightmares and insomnia. It also induces liver enzymes, which changes how the body handles other drugs.

How your body processes Phenobarbital

▾

Taken by mouth, phenobarbital is a long-acting barbiturate. It starts working in about 1 hour or longer and lasts roughly 10 to 12 hours. After an IV dose, onset is about 5 minutes, with peak effect after 15 minutes or more. Its half-life averages about 79 hours in adults and about 110 hours in children and newborns. It is broken down by the liver, and about 25% to 50% leaves unchanged in the urine.

How to store Phenobarbital

▾

Store at 20°- 25°C (68°- 77°F) . Protect from light and moisture. Dispense in a tight, light-resistant container as defined in the USP using a child-resistant closure.

Written from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →

174

Supplements & herbs that interact with Phenobarbital

174 supplements and herbal products have documented interactions with Phenobarbital in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.

Severity mix
  • Major · 10
  • Moderate · 143
  • Minor · 21
1,4-BUTANEDIOL Major ACTIVATED CHARCOAL Major BEER Major GAMMA-HYDROXYBUTYRATE (GHB) Major HENBANE Major KAVA Major L-TRYPTOPHAN Major SCOPOLIA Major +166 more
Every supplement checked against Phenobarbital — ranked by severity The full interaction hub: 10 major · 143 moderate · 21 minor · every one linked to its full report. Check Phenobarbital against your exact supplements

Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.

11

Nutrient depletion considerations

Phenobarbital has been associated with lower levels of 11 nutrients in the clinical literature. This does not mean a deficiency will occur — it means these may be worth discussing with your pharmacist or healthcare provider, especially with long-term use.

Evidence & significance mix
  • Higher significance · 4
  • Moderate · 6
  • Unrated · 1
ACETYL-L-CARNITINE Insignificant Depletion L-CARNITINE Insignificant Depletion PROPIONYL-L-CARNITINE Insignificant Depletion VITAMIN K Insignificant Depletion BIOTIN Moderate Depletion CALCIUM Moderate Depletion FOLIC ACID Moderate Depletion VITAMIN B12 Moderate Depletion +3 more
See the full Phenobarbital nutrient depletion report

Educational information from a licensed clinical database (Natural Medicines) — not medical advice. Do not start or stop medications or supplements without professional guidance.

Phenobarbital: pharmacist answers to common questions

Quick, plain-English answers to the questions patients ask most about Phenobarbital — the kind of thing our pharmacy team would talk through with you at the counter.

What is phenobarbital used for?

▾
It is used as a sedative and to control seizures. The tablets and oral solutions cover both. The injections have additional uses, such as short-term insomnia, sedation before surgery and emergency seizures. Sezaby is only for newborns with seizures.

Can I stop taking it if I feel fine?

▾
Please don't stop on your own. Phenobarbital can cause physical dependence, and stopping suddenly can lead to withdrawal problems like delirium and seizures. If you need to stop, your prescriber will taper the dose gradually.

Is it safe to drink alcohol or take pain medicine with it?

▾
No, this is a big one. Alcohol and other sedating drugs add to the drowsiness. Opioid pain medicines combined with phenobarbital can cause dangerously slow breathing, coma and death. Always tell me or your prescriber about everything you take.

What side effects should I expect?

▾
Drowsiness, a groggy “hangover” feeling and dizziness are common. Some people, especially children, get restless or irritable instead of sleepy. Call your doctor right away for a rash, trouble breathing, or fever with swelling.

Can I take it if I'm pregnant or breastfeeding?

▾
Talk to your doctor first. Phenobarbital can harm a developing baby and cause withdrawal in newborns exposed late in pregnancy. It also passes into breast milk and can make babies sleepy or affect their breathing.

Will it interact with my other medicines?

▾
It might. Phenobarbital speeds up liver enzymes that break down many drugs, which can make them less effective. Other medicines can also change phenobarbital levels. Check with me before starting or stopping anything.

Is Phenobarbital available over the counter?

▾
No. Phenobarbital is a prescription medicine: every Phenobarbital product listed with the FDA is prescription only, so it is not sold over the counter. Your prescriber decides whether it is appropriate for you, and your pharmacist dispenses it.

Is Phenobarbital a controlled substance?

▾
Yes — Phenobarbital is a federally controlled substance (Schedule IV) in the United States, so how it is prescribed, refilled and dispensed is regulated by the DEA.

When was Phenobarbital first available?

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The earliest FDA record we hold for Phenobarbital is from 1967: its first approval in Drugs@FDA or its earliest product listing in the NDC Directory, whichever is older. Many older medicines were in use before their first formal FDA approval, so this is the earliest date on record, not necessarily when Phenobarbital was first used.

Who makes Phenobarbital?

▾
30 companies currently list Phenobarbital products in the FDA's NDC Directory, including Bryant Ranch Prepack, Proficient Rx LP, Westminster Pharmaceuticals, LLC. That count includes repackagers and distributors as well as manufacturers (companies that sell only the raw ingredient are not counted), so fewer companies actually make it; the label on your bottle names the one that supplied yours.

Answers drafted from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →

More about Phenobarbital on HelloPharmacist

📊Phenobarbital supplement interactions174 checked — ranked by severity 🌿Drug & Supplement CheckerPhenobarbital vs. vitamins & herbs 💬Ask a PharmacistFree answer, usually < 24h 🔎NDC & pricing lookupFind Phenobarbital NDCs & costs 🅰️Browse Drugs A–ZLook up any medication
Detailed data & references for Phenobarbital Forms & strengths, pricing, billing codes, manufacturers, safety reports and sourcing — the data behind the page. Most people can stop here. Each section below opens on a tap.

Phenobarbital forms and strengths (how it comes)

Phenobarbital is available in 3 forms. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.

Tablet

By mouth
How this form is used
What it may be used for
  • Phenobarbital tablets are used as a sedative.
  • Phenobarbital tablets are used for generalized and partial seizures.
Important instructions
  • Phenobarbital tablets are taken by mouth, with the dose individualized by age, weight and condition.
  • For daytime sedation, Phenobarbital tablets are generally taken in 2 to 3 divided doses a day in adults.
Available strengths 8 strengths
15 mg 16.2 mg 30 mg 32.4 mg 60 mg 64.8 mg
Show 2 more strengths Show fewer strengths
97.2 mg 100 mg
219 FDA-listed product records ⓘ

Injection

Into a muscle · Into a vein
Brands Sezaby
How this form is used
What it may be used for
  • Sezaby is used for neonatal seizures in term and preterm infants.
  • Phenobarbital Sodium injection is used for sedation, short-term insomnia, sedation before surgery, and long-term and emergency seizure control.
  • Phenobarbital Sodium injection is also used in children as an anticonvulsant and sedative.
Important instructions
  • Sezaby is given by IV infusion into a large vein, with a starting dose followed by maintenance dosing for up to 5 days.
  • Sezaby must be reconstituted (mixed) with sodium chloride injection before use.
  • Phenobarbital Sodium injection can be given into a muscle or vein, but only when oral use is impossible or impractical.
  • Phenobarbital Sodium injection must never be given into an artery or under the skin.
Available strengths 3 strengths
65 mg/mL 100 mg 130 mg/mL
38 FDA-listed product records ⓘ

Oral solution

By mouth
How this form is used
What it may be used for
  • Phenobarbital Oral Solution is used as a sedative.
  • Phenobarbital Oral Solution is used for generalized and partial seizures.
Important instructions
  • Phenobarbital Oral Solution is taken by mouth, with the dose individualized by age, weight and condition.
  • For sedation, Phenobarbital Oral Solution is generally taken in 2 to 3 divided doses a day in adults.
Available strengths 3 strengths
20 mg/5 mL 30 mg/7.5 mL 60 mg/15 mL
30 FDA-listed product records ⓘ

Phenobarbital on the U.S. market: products, makers and brands

How Phenobarbital appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.

30 companies list 184 Phenobarbital product records with the FDA, mostly as tablet, injection, oral solution; the earliest marketing or approval year on record is 1967. Brand names on the directory include Sezaby, Fidoquel; the rest are generics.

3
Dose forms ⓘ
30
Labelers (makers, repackagers, distributors)
4
Brand names
184
FDA-listed product records ⓘ
1967
Earliest FDA record ⓘ

FDA-listed product records by dose form (tablet variants merged) — FDA National Drug Code Directory. Record counts are not sales or prescription volume.

Also listed with the FDA, not a patient dose form: Powder (13) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.

Bryant Ranch Prepack12%
Proficient Rx LP11%
Westminster Pharmaceuticals, LLC10%
Chartwell RX, LLC9%
Rising Pharma Holdings, Inc.5%
Trigen Laboratories, LLC5%
Other makers48%

Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.

How widely Phenobarbital is used (Medicaid data)

A general measure of how commonly Phenobarbital is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.

Think of this as a proxy for how widely Phenobarbital is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.

164,240
Medicaid prescriptions filled (Q1–Q4 2025)
$4.7M gross Medicaid reimbursement (before mandatory rebates — net cost is lower)

How commonly is Phenobarbital prescribed? Of the 1,601 medications we measure, Phenobarbital ranks #422 by Medicaid prescriptions — more than 74% of them.

Where Phenobarbital ranks among the drugs we measure · Q1–Q4 2025 · neighbors ±5
Total prescriptions — #422 of 1,601
#417 Serdexmethylphenidate... 170,163 Rx #418 Linagliptin 168,433 Rx #419 Diazepam Nasal Spray 167,415 Rx #420 Bupivacaine 166,102 Rx #421 Cefadroxil 165,523 Rx #422 Phenobarbital 164,240 Rx #423 Doxazosin 163,836 Rx #424 Fludrocortisone Acetat... 163,820 Rx #425 Ritonavir 162,610 Rx #426 Ursodiol 159,875 Rx #427 Tobramycin Ophthalmic 159,866 Rx

Utilization by Phenobarbital product

Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.

The 4 mg/mL oral solution is the most-dispensed Phenobarbital product — about 29% of these Medicaid prescriptions.

phenobarbital 4 MG/ML Oral Solution Most dispensed

48,380 Medicaid prescriptions (Q1–Q4 2025) 29% of Phenobarbital prescriptions shown $1.9M gross reimbursement (before rebates) ≈ $39 per prescription (gross)

Summed across the 5 of 53 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 702519

phenobarbital 32.4 MG Oral Tablet

37,150 Medicaid prescriptions (Q1–Q4 2025) 23% of Phenobarbital prescriptions shown $665,001 gross reimbursement (before rebates) ≈ $18 per prescription (gross)

Summed across the 14 of 72 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 199167

phenobarbital 64.8 MG Oral Tablet

26,562 Medicaid prescriptions (Q1–Q4 2025) 16% of Phenobarbital prescriptions shown $473,669 gross reimbursement (before rebates) ≈ $18 per prescription (gross)

Summed across the 12 of 68 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 199168

phenobarbital 30 MG Oral Tablet

11,790 Medicaid prescriptions (Q1–Q4 2025) 7% of Phenobarbital prescriptions shown $196,070 gross reimbursement (before rebates) ≈ $17 per prescription (gross)

Summed across the 10 of 55 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 312362

phenobarbital 97.2 MG Oral Tablet

11,283 Medicaid prescriptions (Q1–Q4 2025) 7% of Phenobarbital prescriptions shown $219,514 gross reimbursement (before rebates) ≈ $19 per prescription (gross)

Summed across the 7 of 62 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 199164

phenobarbital 60 MG Oral Tablet

8,852 Medicaid prescriptions (Q1–Q4 2025) 5% of Phenobarbital prescriptions shown $162,563 gross reimbursement (before rebates) ≈ $18 per prescription (gross)

Summed across the 10 of 52 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 198089

phenobarbital 16.2 MG Oral Tablet

7,919 Medicaid prescriptions (Q1–Q4 2025) 5% of Phenobarbital prescriptions shown $115,169 gross reimbursement (before rebates) ≈ $15 per prescription (gross)

Summed across the 10 of 66 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 198086

phenobarbital 100 MG Oral Tablet

7,172 Medicaid prescriptions (Q1–Q4 2025) 4% of Phenobarbital prescriptions shown $133,091 gross reimbursement (before rebates) ≈ $19 per prescription (gross)

Summed across the 7 of 51 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 198083

phenobarbital 130 MG/ML Injectable Solution

2,294 Medicaid prescriptions (Q1–Q4 2025) 1% of Phenobarbital prescriptions shown $613,051 gross reimbursement (before rebates) ≈ $267 per prescription (gross)

Summed across the 1 of 12 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 312370

phenobarbital 15 MG Oral Tablet

1,813 Medicaid prescriptions (Q1–Q4 2025) 1% of Phenobarbital prescriptions shown $27,393 gross reimbursement (before rebates) ≈ $15 per prescription (gross)

Summed across the 6 of 52 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 312357

phenobarbital 65 MG/ML Injectable Solution

499 Medicaid prescriptions (Q1–Q4 2025) <1% of Phenobarbital prescriptions shown $124,729 gross reimbursement (before rebates) ≈ $250 per prescription (gross)

Summed across the 1 of 15 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 198368

1 ML phenobarbital sodium 130 MG/ML Injection

386 Medicaid prescriptions (Q1–Q4 2025) <1% of Phenobarbital prescriptions shown $24,415 gross reimbursement (before rebates) ≈ $63 per prescription (gross)

Summed across the 1 of 10 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 2671204

1 ML phenobarbital sodium 65 MG/ML Injection

140 Medicaid prescriptions (Q1–Q4 2025) <1% of Phenobarbital prescriptions shown $17,088 gross reimbursement (before rebates) ≈ $122 per prescription (gross)

Summed across the 1 of 6 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 2671207

Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.

Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Phenobarbital, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 85 of 574 listed Phenobarbital NDCs with Medicaid activity.

Compare Phenobarbital products

A representative set of FDA-listed product records for Phenobarbital — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)

Showing 128 of 184 products — FDA National Drug Code Directory. See every product, package size and price: browse all 184 Phenobarbital NDCs →

Phenobarbital recall history

A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.

The FDA’s enforcement reports list one Phenobarbital recall since July 2021, covering 2 product listings. It is no longer listed as ongoing. A recall names specific lots from one company, so check the lot number on your own bottle rather than assuming every product is affected; your pharmacist can check whether your supply came from an affected lot.

Class II Mar 14, 2022 · Terminated · Vitae Enim Vitae Scientific, Inc.
Lack of Assurance of Sterility: deviations from Current Good Manufacturing Practices (CGMP) that call into question the sterility of products intended to be sterile.
  • PHENOBARBITAL Sodium Injection, USP, 130 mg/mL, packaged as a) 25 x 1 mL Vials per box (NDC 42494-416-25) and b) 3 x 1mL Vials per box (NDC 42494-416-03), Rx only, Manufactured for Cameron Pharmaceut… Lots: Lot # a) 20VPSI011, Exp. 4/30/2022; 20VPSI014, Exp. 5/31/2022; 20VPSI020, 20VPSI022, 20VPSI023, Exp. 7/31/2022; 21VPSI007, Exp. 3/31/2023; 21VPSI013, Exp. 5/31/2023; 21VPSI027, Exp. 6/30/2023; 21VPSI039, Exp. 8/31/2023; 21VPSI042, Exp. 10/… FDA record D-0744-2022 →
  • PHENOBARBITAL Sodium Injection, USP, 65mg/mL, packaged as a) 25 x 1 mL Vials per box (NDC 42494-415-25) and b) 3 x 1 mL Vials per box (NDC 42494-415-03), Rx only, Manufactured for Cameron Pharmaceuti… Lots: Lot #: a) 20VPSI007, Exp 3/31/2022; 20VPSI015, Exp 5/30/2022; 20VPSI018, Exp 6/1/2022; 20VPSI032, Exp 11/30/2022; 21VPSI002, 21VPSI003, Exp 1/31/2023; 21VPSI006, Exp 3/31/2023; 21VPSI012, 21VPSI020, Exp 5/31/2023; 21VPSI035, Exp 7/31/2023;… FDA record D-0743-2022 →

Source: FDA enforcement (recall) reports, via openFDA; our copy was last updated Sep 24, 2026.

RxNorm Concept Web — From Ingredient to Every Form and Strength

This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.

Ingredient (IN) Phenobarbital RxCUI 8134 5 dose forms · 24 strengths
  1. Dose form (SCDF) Injectable Solution RxCUI 373325 In current FDA listings
    Clinical drug / strength (SCD) 15 MG/ML RxCUI 251325 30 MG/ML RxCUI 282462 60 MG/ML RxCUI 282463 65 MG/ML RxCUI 198368 130 MG/ML RxCUI 312370 200 MG/ML RxCUI 199964
  3. Dose form (SCDF) Oral Capsule RxCUI 373323 No current FDA listing
    Clinical drug / strength (SCD) 16 MG RxCUI 198084
  4. Dose form (SCDF) Oral Solution RxCUI 435437 In current FDA listings
    Clinical drug / strength (SCD) 3 MG/ML RxCUI 756143 4 MG/ML RxCUI 702519
  5. Dose form (SCDF) Oral Tablet RxCUI 373326 In current FDA listings
    Clinical drug / strength (SCD) 15 MG RxCUI 312357 16 MG RxCUI 198085 16.2 MG RxCUI 198086 30 MG RxCUI 312362 32 MG RxCUI 312363 32.4 MG RxCUI 199167 50 MG RxCUI 429777 60 MG RxCUI 198089 64.8 MG RxCUI 199168 90 MG RxCUI 312368 97.2 MG RxCUI 199164 100 MG RxCUI 198083

Look up RxCUI 8134 in the RxCUI Atlas →

RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.

💵 What Phenobarbital costs pharmacies (NADAC benchmark)

The national average invoice price pharmacies pay for the drug itself, from CMS's NADAC survey (data as of Sep 30, 2026). This is a supply-cost benchmark — not a retail price and not what you'd pay at the counter.

FormStrengthPharmacy acquisition benchmark
Tablet · Oral 32.4 mg $0.073–$0.079 per tablet NDC details & price history
Tablet · Oral 64.8 mg $0.097–$0.102 per tablet NDC details & price history
Tablet · Oral 16.2 mg $0.049–$0.056 per tablet NDC details & price history
Tablet · Oral 97.2 mg $0.111–$0.118 per tablet NDC details & price history
Tablet · Oral 30 mg $0.142 per tablet NDC details & price history
Tablet · Oral 100 mg $0.213 per tablet NDC details & price history
Tablet · Oral 60 mg $0.181 per tablet NDC details & price history
Tablet · Oral 15 mg $0.077 per tablet NDC details & price history
Liquid · Oral 20 mg/5 mL $0.047 per mL NDC details & price history
Elixir · Oral 20 mg/5 mL $0.047 per mL NDC details & price history
Why show this? Your out-of-pocket cost depends on insurance, pharmacy markup, and discounts — but the acquisition benchmark tells you whether the medication itself is inexpensive or costly, which strengths cost more per dose, and whether a cash-price quote is in a reasonable range. Each row links to the NDC-level record with its full price history.

Source: CMS National Average Drug Acquisition Cost (NADAC), a survey of retail pharmacy invoice prices. Benchmarks shown are the range across package sizes of a representative product for each form and strength — other manufacturers' products may differ.

Phenobarbital brand names

Phenobarbital is sold under 2 brand names in the FDA directory — Sezaby, Fidoquel. A brand and its generic contain the same active ingredient; the brand name belongs to one company's product.

Sezaby Fidoquel

Who makes Phenobarbital: manufacturers and labelers

30 companies list Phenobarbital products with the FDA. By number of product records, the largest are Bryant Ranch Prepack, Proficient Rx LP, Westminster Pharmaceuticals, LLC. Labelers include manufacturers and repackagers; the product in your bottle depends on which one your pharmacy stocks.

Bryant Ranch Prepack 22 Proficient Rx LP 21 Westminster Pharmaceuticals, LLC 18 Chartwell RX, LLC 17 Rising Pharma Holdings, Inc. 9 Trigen Laboratories, LLC 9 Genus Lifesciences 8 Quagen Pharmaceuticals Llc 8 Taro Pharmaceuticals U.S.A. Inc. 8 Winder Laboratories, Llc 8 e5 Pharma, LLC 7 Clinical Solutions Wholesale, LLC 6 Hikma Pharmaceuticals USA Inc. 6 Remedyrepack Inc. 6 Cameron Pharmaceuticals 4 Coupler LLC 4 Par Health USA, LLC 4 BPI Labs LLC 3 PAI Holdings, LLC dba PAI Pharma 3 Kesin Pharma Corporation 2 Nexus Pharmaceuticals, LLC 2 Ajenat Pharmaceuticals LLC 1 American Health Packaging 1 Chartwell Governmental & Specialty RX, LLC. 1

…and 6 more on the FDA NDC directory.

Phenobarbital drug class (RxNorm)

Phenobarbital belongs to the Barbiturates and derivatives class.

Drug family (ATC) Barbiturates and derivatives

Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.

Sources for this Phenobarbital page

Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.

📄
FDA-filed drug labels (SPL) Uses, dosing, warnings & side effects from SPL records retrieved through openFDA; the linked representative set can be verified on DailyMed. ✓ Linked label effective Mar 12, 2026
🏭
Forms, brands & labelersAggregated from ingredient-matched FDA National Drug Code Directory product records for Phenobarbital.
📈
Real-world reportsThe FDA Adverse Event Reporting System (FAERS), served through openFDA.
🚨
Recalls & shortagesopenFDA drug-enforcement reports and the FDA drug-shortage database.
🧾 Clinical label set — FDA-filed SPL labels retained for Phenobarbital after exact ingredient or ingredient-combination matching and applicable route/form matching
Clinical labels in scope
83
Finished products in the current FDA directory
184
Companies listing them (makers, repackagers, distributors)
30
FDA labeler codes behind them ⓘ
34
Linked representative label ⓘ
Westminster Pharmaceuticals, LLC
Linked label effective
Mar 12, 2026
Composite sections available
18
Linked SPL Set ID
e0276d32-80b9-4e06-85f9-3421a013be39
Linked SPL Document ID
e9ead134-956a-408a-8546-3ab0e88229a9
Open the linked representative label on DailyMed ↗

How this page is built

HelloPharmacist combines public FDA and NLM records and does not author the underlying clinical facts. The plain-language sections are written with AI from the FDA-approved label text and reviewed by our pharmacy team before publication. Westminster Pharmaceuticals, LLC is the representative DailyMed label linked for verification and dates. This is general education, not medical advice: always talk to your doctor or pharmacist about your own medicines. How we build and review drug pages →