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Phenobarbital

  • Prescription medicine
  • Withdrawn
  • Identity checked
  • Sources last checked 2026-09-04

This page shows what was measured, who it was measured in, and what that does not settle.

What Phenobarbital does in the body

Sleep laboratory studies have demonstrated that barbiturates reduce the amount of time spent in the rapid eye movement (REM) phase of sleep or dreaming stage.

From the FDA-approved label: Barbiturates are capable of producing all levels of CNS mood alteration from excitation to mild sedation, to 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 physiological sleep. Also, Stages III and IV sleep are decreased.

Why people take it. Generalized tonic-clonic and cortical focal seizures

What happened in people

RNAWiki has not yet published a reviewed conclusion for this use.

A fixed RNAWiki sentence

Where this came from

Wording RNAWiki always uses, not a finding about this substance.

No reviewed claim names a result for any goal on this record.

No source is stored against this line.

The limit that matters most

Not recorded.

Where it acts
Not recorded.
Kind of result
No result is published, so no kind of result applies yet
Supervision
Professional supervision is normally required. A regulator classifies this substance in a way that restricts how it is supplied.

What the registries record it as

  • The substance registry classes this as chemical.

    FDA substance registry · YQE403BP4D · read 2026-08-29

Where each sentence above came from

A person wrote this explanation into the record, with the studies named in the path below.

The recorded use, written for a reader without medical training. Not signed off.

No statement of the main limit is recorded.

The four opening statements run to 110 words.

Words this page uses

Four words worth knowing first

Chosen from what this page shows, with each one explained before the word it depends on.

Biomarker

A biomarker is a number from a test that stands in for something about health.

A picture of it, and where the picture fails

A biomarker is like a fuel gauge.

Where that stops being true. A gauge is wired to the tank. Many biomarkers are only loosely tied to health.

What people get wrong. A better number is read as a better life. Several medicines improved a number and helped nobody.

A measurable indicator used as a substitute for a clinical outcome of interest.

Placebo

A placebo is a dummy treatment given so the real one can be compared with it.

A picture of it, and where the picture fails

A placebo is like a blank control in an experiment.

Where that stops being true. A blank does nothing. People given a placebo often do get better.

What people get wrong. A placebo effect is read as imaginary. The improvement is measured and real.

An inactive intervention matched in appearance to the test intervention, used to control for non-specific effects.

Comparator

A comparator is whatever the treatment was measured against.

A picture of it, and where the picture fails

It is like the other runner in a race.

Where that stops being true. A race has one winner. A study can show both arms improved.

What people get wrong. Results are read without asking what the other group got. Beating nothing is not beating a treatment.

The control condition against which the experimental intervention is assessed.

What happened in peopleRead from sources, not yet reviewed

What happened in people

Each card is one study: the exact question it asked, who was in it, and whether it showed what it set out to show.

AEDs-induced cADRs incidence

The study did not show it

Who was studied
NCT03184597
How many people
4000
Study design
Not applicable
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated

What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.

The limits of this study, and where it came from

Main limit. No limitation is recorded for this study.

How far it carries. This study is recorded from the curated record, not from the registry match.

Form and route. Intravenous

Interval reported. Not recorded in this summary

Written into the record, not signed off as a reviewed claim.

  • openFDA Drugs@FDA · a recorded source, not a stored snapshot
  • openFDA NDC Directory · a recorded source, not a stored snapshot
  • openFDA SPL label · a recorded source, not a stored snapshot
  • PubChem PUG-REST · a recorded source, not a stored snapshot

Summary of Treatment-Emergent Adverse Events (TEAEs)

The study did not show it

Who was studied
NCT02535091
How many people
1345
Study design
Phase 3
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated

What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.

The limits of this study, and where it came from

Main limit. No limitation is recorded for this study.

How far it carries. This study is recorded from the curated record, not from the registry match.

Form and route. Intravenous

Interval reported. Not recorded in this summary

Written into the record, not signed off as a reviewed claim.

  • openFDA Drugs@FDA · a recorded source, not a stored snapshot
  • openFDA NDC Directory · a recorded source, not a stored snapshot
  • openFDA SPL label · a recorded source, not a stored snapshot
  • PubChem PUG-REST · a recorded source, not a stored snapshot

Neonatal intracranial hemorrhage or death

The study did not show it

Who was studied
NCT00009620
How many people
610
Study design
Phase 3
Compared against
Not recorded for this study
Kind of result
Living longer, or avoiding a major event
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated

What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.

The limits of this study, and where it came from

Main limit. No limitation is recorded for this study.

How far it carries. This study is recorded from the curated record, not from the registry match.

Form and route. Intravenous

Interval reported. Not recorded in this summary

Written into the record, not signed off as a reviewed claim.

  • openFDA Drugs@FDA · a recorded source, not a stored snapshot
  • openFDA NDC Directory · a recorded source, not a stored snapshot
  • openFDA SPL label · a recorded source, not a stored snapshot
  • PubChem PUG-REST · a recorded source, not a stored snapshot

Assessment of frequency and severity of adverse events

The study did not show it

Who was studied
NCT02374567
How many people
407
Study design
Phase 3
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated

What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.

The limits of this study, and where it came from

Main limit. No limitation is recorded for this study.

How far it carries. This study is recorded from the curated record, not from the registry match.

Form and route. Intravenous

Interval reported. Not recorded in this summary

Written into the record, not signed off as a reviewed claim.

  • openFDA Drugs@FDA · a recorded source, not a stored snapshot
  • openFDA NDC Directory · a recorded source, not a stored snapshot
  • openFDA SPL label · a recorded source, not a stored snapshot
  • PubChem PUG-REST · a recorded source, not a stored snapshot

comparison of electroencephalogram score to neurologic outcome evaluated by cerebral performance category

The study did not show it

Who was studied
NCT02886039
How many people
400
Study design
Not applicable
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated

What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.

The limits of this study, and where it came from

Main limit. No limitation is recorded for this study.

How far it carries. This study is recorded from the curated record, not from the registry match.

Form and route. Intravenous

Interval reported. Not recorded in this summary

Written into the record, not signed off as a reviewed claim.

  • openFDA Drugs@FDA · a recorded source, not a stored snapshot
  • openFDA NDC Directory · a recorded source, not a stored snapshot
  • openFDA SPL label · a recorded source, not a stored snapshot
  • PubChem PUG-REST · a recorded source, not a stored snapshot

Core Phase: European Medicine Agency (EMA): Seizure Frequency Response Rate

The study did not show it

Who was studied
NCT01713946
How many people
366
Study design
Phase 3
Compared against
Not recorded for this study
Kind of result
A number that stands in for health
What was found
Result not recorded on this page
Repeated elsewhere
Unreplicated

What this does not prove. A study that did not show an effect does not show that no effect exists anywhere.

The limits of this study, and where it came from

Main limit. No limitation is recorded for this study.

How far it carries. This study is recorded from the curated record, not from the registry match.

Form and route. Intravenous

Interval reported. Not recorded in this summary

Written into the record, not signed off as a reviewed claim.

  • openFDA Drugs@FDA · a recorded source, not a stored snapshot
  • openFDA NDC Directory · a recorded source, not a stored snapshot
  • openFDA SPL label · a recorded source, not a stored snapshot
  • PubChem PUG-REST · a recorded source, not a stored snapshot
What we know
RNAWiki holds 6 written-up human studies for this substance, each with the question it asked.
How we know it
Each card names the study, the number of people and what the study set out to measure.
What this does not prove
These summaries were written by a person and have not been signed off as reviewed claims.
Why it matters
A study that failed is as informative as one that worked, and both are here.
What we still do not know
No reviewed claim exists, so no exact population, effect size or interval is published yet.

What is missing or unclearRead from sources, not yet reviewed

Were people like you studied?

RNAWiki cannot tell whether a study fits you. It can show who was in it, and where the result stops carrying.

Who was studied

People similar to this profile were included.

  • Parenteral 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…

Who is missing from the studies

  • Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.

What the label states about particular groups

  • On pediatric, the label states: “The safety and effectiveness of SEZABY have been established for the treatment of neonatal seizures in term and preterm infants, and the information on this use is discussed throughout the labeling.”

    US prescribing information · 8c7d0402-4977-4c25-bc4b-11db91339e9a · read 2026-08-30

Where the result stopped carrying

  • This is a scope explorer, not a diagnosis engine.
  • It shows who was studied so you can see whether people similar to you were included.

RNAWiki cannot tell whether a study fits you. It can show who was in it.

What it would be like to takeRead from sources, not yet reviewed

Why it might seem to do nothing

A real effect and a noticed effect are different things. These are the recorded reasons the two come apart.

It was studied in different people

The people in the studies were not much like the reader.

On this record: Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.

The evidence may simply be wrong

Small early studies often do not hold up.

On this record: RNAWiki has not yet published a reviewed conclusion for this use.

Other reasons RNAWiki checked and found nothing for (11)
It was studied for a different goal
The studies measured something else entirely. Nothing in this record points to this reason.
A different form was studied
The studied form is not the form on the shelf. Nothing in this record points to this reason.
There was nothing to correct
Where a level is already normal, topping it up may change nothing. Nothing in this record points to this reason.
Something else had to happen too
In the studies it was paired with training, a diet or another treatment. Nothing in this record points to this reason.
The change is too small to feel
A real change can still sit below what a person notices. Nothing in this record points to this reason.
Day-to-day swing hides it
Sleep, food, stress and time of day move most numbers more than this would. Nothing in this record points to this reason.
Not enough time yet
The studies ran longer than the person has waited. Nothing in this record points to this reason.
It was not taken as studied
Missed days change the result, and studies count them. Nothing in this record points to this reason.
Something else changed at the same time
Two changes at once cannot be told apart afterwards. Nothing in this record points to this reason.
The product may not be what it says
Contents of a sold product are not always what the label states. Nothing in this record points to this reason.
No recorded reason
RNAWiki has nothing stored that would explain it. Nothing in this record points to this reason.

None of these is a reason to take more. Taking more is not a step this page ever suggests.

What it would be like to takeRead from sources, not yet reviewed

What taking it involves

The recorded facts about getting hold of it and using it. Nothing here is a suggestion about what you should do.

How it is supplied

Withdrawn

Quoted from a source

Where this came from

Copied from a source RNAWiki stored, with the source named.

Read from the recorded approval status.

No source is stored against this line.

Form and route

Intravenous

Source-linked record

Where this came from

A person wrote this into the record with the study named beside it. No reviewer has signed it off.

The form and route recorded on this substance.

No source is stored against this line.

Who oversees it

Professional supervision is normally required. A regulator classifies this substance in a way that restricts how it is supplied.

Quoted from a source

Where this came from

Copied from a source RNAWiki stored, with the source named.

Suppression classes recorded: S3, S6, S8.

No source is stored against this line.

What is in the pack

Sold as powder, tablet, solution, injection, solution, given by the intravenous, oral, intramuscular route.

Source-linked record

Where this came from

A person wrote this into the record with the study named beside it. No reviewer has signed it off.

Recorded notes on how this is sold and what that means for what is in the pack.

No source is stored against this line.

Where it is registered

Regulatory records are listed in the technical disclosure at the foot of this page.

Counted from records

Where this came from

A count of rows RNAWiki holds. It describes our records, not your body.

Register entries are stored per jurisdiction and shown with their dates.

No source is stored against this line.

Why people stop

Not recorded.

Nothing recorded

Where this came from

RNAWiki holds nothing here and says so rather than guessing.

No record of why people stopped taking it is stored for this substance.

No source is stored against this line.

What it would be like to takeNothing found in the sources checked

What can go wrong

Sorted by where each line came from. A regulator's label and a report somebody sent in are not the same kind of fact.

Nothing found in the sources checked

No harm is recorded against this substance in the sources RNAWiki checked. Finding nothing is not the same as showing there is nothing.

The sources listed were searched and held nothing. That is not the same as nothing existing.

Over a long time. No completed tested study window is recorded, so long-term effects are not established by the registry record.

Groups the studies covered thinly. Which groups were under-represented in the studies has not been recorded for this substance. Pregnancy, breastfeeding, children, older adults, and people with liver or kidney conditions are commonly excluded from trials; nothing here says whether they were.

What is missing or unclearRead from sources, not yet reviewed

Does the exact form matter?

Evidence belongs to the exact thing that was tested. A different salt, a different mixture or a different preparation is a different question.

The form that was studied

Intravenous

Source-linked record

Where this came from

A person wrote this into the record with the study named beside it. No reviewer has signed it off.

The form used in the studies cited on this page.

No source is stored against this line.

What is sold

Not recorded.

Nothing recorded

Where this came from

RNAWiki holds nothing here and says so rather than guessing.

Nothing further is recorded about which forms are sold.

No source is stored against this line.

What is recorded as being sold

  • 212 products list this as an active ingredient in the United States drug directory. 201 of them contain it and nothing else.

    FDA National Drug Code directory · 71335-2993 · read 2026-08-29

  • They are sold as elixir, injection, injection, solution, liquid, powder and solution, taken intramuscular, intravenous and oral.

    FDA National Drug Code directory · 71335-2993 · read 2026-08-29

  • 91 published labels name it as an active ingredient. 83 of them describe this substance alone, which is where its own label text on this page comes from.

    US prescribing information · 7741e9ab-54ea-4c7e-9d64-daff922704ba · read 2026-08-29

  • Those labels are classed as human prescription drug.

    US prescribing information · 7741e9ab-54ea-4c7e-9d64-daff922704ba · read 2026-08-29

  • 20 marketed supplement labels list this ingredient, classed as botanical and vitamin.

    NIH Dietary Supplement Label Database · 232089 · read 2026-08-29

  • Those labels carry all other, nutrient and structure/function claims. A claim of that kind is written by the manufacturer and is not assessed by any regulator, so its presence says nothing about whether it is true.

    NIH Dietary Supplement Label Database · 232089 · read 2026-08-29

  • SEZABY is intravenous at 3 DOSAGE FORMS AND STRENGTHS For injection: 100 mg of phenobarbital sodium as a white to off-white lyophilized powder in a single-dose vial for reconstitution., recorded as fda label in effect 2025-12-23 in the United States.

    US prescribing information · 8c7d0402-4977-4c25-bc4b-11db91339e9a · read 2026-08-30

  • Recorded price in US: 0.04212 USD per one millilitre, across 9 priced products whose strengths and pack forms differ, as of 2026-08-26, paid by retail pharmacies buying the product, as surveyed by the Centers for Medicare & Medicaid Services. It is not a list price, an insurance price, or what anyone pays at a counter..

    Recorded source · 2026-08-26 · read 2026-08-28

  • Recorded price in US: 0.04945–0.24718 USD per one unit as the pricing file counts it — a tablet, capsule, patch or single item, across 121 priced products whose strengths and pack forms differ, as of 2026-08-26, paid by retail pharmacies buying the product, as surveyed by the Centers for Medicare & Medicaid Services. It is not a list price, an insurance price, or what anyone pays at a counter..

    Recorded source · 2026-08-26 · read 2026-08-28

Evidence carries across two names for one substance. It does not carry across a salt, a mirror form or a mixture.

What it would be like to takeRead from sources, not yet reviewed

What you could measure

This one is decided with a clinician, so this section holds questions to ask rather than a plan to run.

Self-experiment planning is not offered for a prescription or clinician-supervised medicine, withdrawn medicine. The questions below are for a clinician or pharmacist.

Questions worth asking

  • Which of the trials of Phenobarbital studied people like me?
  • What was measured, and for how long?
  • Was the result a laboratory value or a health outcome?
  • What would we watch for, and when would we stop?

Tracking can show whether something changed for you. It cannot show what caused it.

RNAWiki records evidence. It does not say whether this substance is right for you.

What is missing or unclearRead from sources, not yet reviewed

What nobody knows yet

Open questions, each with why it is open and what would close it.

Missing populations

Which groups were under-represented in the studies has not been recorded.

Why it matters. Recorded by the evidence model as a gap on this record.

What would answer it

A study that measures it, and a reviewer to sign it off.

Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.

Missing long-term data

No completed tested study window is recorded.

Why it matters. Recorded by the evidence model as a gap on this record.

What would answer it

A study that measures it, and a reviewer to sign it off.

Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.

No reviewed conclusion

RNAWiki has not yet published a reviewed conclusion for this use.

Why it matters. Recorded by the evidence model as a gap on this record.

What would answer it

A study that measures it, and a reviewer to sign it off.

Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.

Missing interaction studies

No interaction was found in the registers checked. Not finding one is not the same as showing there is none.

Why it matters. Recorded by the evidence model as a gap on this record.

What would answer it

A study that measures it, and a reviewer to sign it off.

Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.

Formulation uncertainty

Several salts, forms or products of Phenobarbital are recorded. Results from one form may not transfer to another.

Why it matters. Recorded by the evidence model as a gap on this record.

What would answer it

A study that measures it, and a reviewer to sign it off.

Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.

Mechanism not reviewed

No reviewed mechanism story exists for this substance.

Why it matters. Recorded by the evidence model as a gap on this record.

What would answer it

A study that measures it, and a reviewer to sign it off.

Last checked 2026-09-04. Searched: The sources listed in the receipts at the foot of this page.

What happened in peopleRead from sources, not yet reviewed

Check any of this yourself

Every line above traced back to the study it came from. This is the technical layer, and the vocabulary changes here.

How many documents were read

  • 83 documents were read for this substance.

    RNAWiki source record

  • 60 of them state the same halfLife, and they agree.

    RNAWiki source record

Where else this substance is registered

FDA substance identifier (UNII)
YQE403BP4D
RxNorm concept
312362

Checks this page had to pass

  • Passed

    Identity resolved

    no open identity hold

  • Passed

    No unresolved merge across substance families

    no quarantine open

  • Passed

    Every public sentence names a source

    The opening statement carries the origin: Written into the record, not signed off.

  • Not passed

    Trial roles classified for highlighted evidence

    No registered study is classified as testing this substance.

  • Passed

    No internal keys in reader text

    enforced by the copy-contract test over the rendered page

  • Passed

    Safety mode resolved

    Suppression classes recorded: S3, S6, S8.

  • Passed

    Canonical metadata present

    slug and display name present

What is missing or unclearRead from sources, not yet reviewed

How this medicine reached us

Kept near the foot of the page. A historical event moves up only when it changes something about this substance today.

  1. Withdrawn; no reason is published (ChEMBL)

What the approval register records

  • 1 approved application covers products containing this substance. The earliest was NDA215910, approved 20221117 to SUN PHARM INDS INC.

    Drugs@FDA application register · NDA215910 · read 2026-08-29

  • Marketing status on the register: prescription.

    Drugs@FDA application register · NDA215910 · read 2026-08-29

  • The earliest marketing start date recorded for a listed product is 19670321.

    FDA National Drug Code directory · 71335-2993 · read 2026-08-29

What is missing or unclearRead from sources, not yet reviewed

What to learn next

Ordered by what would most change how you read this page, starting with what is easiest to misunderstand.

This order is fixed in code and does not count clicks or time on the page.

What is not here

9 questions this page could not answer

These sections were prepared and left out because there was nothing to put in them. They are listed rather than hidden, so the gaps in this record are visible.

  • What was measured, goal by goal — found nothing in the sources checked.
  • How close this is to real life — found nothing in the sources checked.
  • The path through the body — found nothing in the sources checked.
  • Felt, measured, or meaningful — found nothing in the sources checked.
  • How long anything takes — found nothing in the sources checked.
  • What it may clash with — found nothing in the sources checked.
  • Other ways to the same goal — found nothing in the sources checked.
  • Claims that go past the evidence — found nothing in the sources checked.
  • What changed on this page — found nothing in the sources checked.

The record as stored

The full record, for auditing

Everything above is built from what is below. This layer keeps the technical vocabulary, record identifiers and every stored row, so a reader who wants to check the page can.

Recorded evidence blocks (11)

On the Phenobarbital label: indicated for what?


"A. Sedative B.": indications and usage on Phenobarbital's label. DailyMed label · b43c3611-24f6-4eaf-ac68-c2807f92ca98 · 2026-08-04

32 registered trials of Phenobarbital — at which phases?


Registered studies posting no result
25 of 32

32 registered studies of Phenobarbital: 11 phase3, 7 na, 6 phase4, 5 phase2, 3 phase1, 2 na or unstated. CLINICALTRIALS_SNAPSHOT · 2026-09-01

456 with a PubMed record

Show the evidence
  • phase3
    11
  • na
    7
  • phase4
    6
  • phase2
    5
  • phase1
    3
  • na or unstated
    2
6 more recorded rows
  • completed
    13
  • terminated
    7
  • unknown
    4
  • withdrawn
    4
  • not yet recruiting
    2
  • recruiting
    2

recorded 2026-09-01 · last checked 2026-09-04

10 of Phenobarbital's trials stopped: futility/efficacy, accrual/recruitment, other?


futility/efficacy (1), accrual/recruitment (5) and other (4): Phenobarbital's stop wording, clustered. CLINICALTRIALS_SNAPSHOT · 2026-09-01

"IRB needs updated"; 10 of 32 registered studies

Show the evidence

Trial

  • NCT00530413
    withdrawn; "IRB needs updated"
  • NCT01089504
    terminated; "Inadequate rate of enrollment"
  • NCT01175668
    terminated; "Based on the planned interim analysis results at 50% recruitment, after IRB reviewed the results, further enrollment was stopped."
  • NCT02550028
    terminated; "The study was concluded as planned upon reaching its predetermined endpoint, which included the completion of data collection and achievement of the necessary sample size for statistical significance."
  • NCT02726867
    withdrawn; "No participants enrolled"
  • NCT03586089
    terminated; "Difficulty recruiting patients"
4 further recorded trials
  • NCT03602118
    withdrawn; "Sponsor withdrawing the subject IND"
  • NCT03788889
    withdrawn; "internal practice and policy limitations including time commitment / workflow issues"
  • NCT04320940
    terminated; "Insufficient participant recruitment hindered the study's progress, preventing robust data collection and compromising statistical power"
  • NCT06081283
    terminated; "Low recruitment"

recorded 2026-09-01 · last checked 2026-09-04

Human studies of Phenobarbital used Phenobarbital Sodium Injection 20 mg — over how long?


studies of Phenobarbital used the recorded amount. ClinicalTrials.gov · 2026-09-01

2 recorded entries; human; also "Phenobarbital Sodium Injection 20 mg", "Phenobarbital Sodium Injection 40 mg"

Show the evidence

human

  • NCT03602118
    Phenobarbital Sodium Injection 20 mg
  • NCT03602118
    Phenobarbital Sodium Injection 40 mg

recorded 2026-09-01 · last checked 2026-09-04

Phenobarbital's half-life is 118 hours — which schedules were studied?


118 hours, the half-life Phenobarbital's label states: "The plasma half-life for phenobarbital in adults ranges between 53 and 118 hours with a mean of 79 hours." DailyMed label · b43c3611-24f6-4eaf-ac68-c2807f92ca98 · 2026-08-04

Show the evidence
  • half life pharmacokinetics
    118 hours; The plasma half-life for phenobarbital in adults ranges between 53 and 118 hours with a mean of 79 hours.
  • metabolism pharmacokinetics
    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.

recorded 2026-08-04 · last checked 2026-09-04

Which 7 trials of Phenobarbital posted no result?


Posted no result
7 of 7 completed trials
Registrations
NCT00009620, NCT02810782, NCT01224457, NCT01284556, NCT03650270 and NCT03632915, and 1 more
Completion dates
oldest 1997-02; newest 2023-06-15
Show the evidence

Trial

  • NCT00009620
    1997-02
  • NCT02810782
    2007-12
  • NCT01224457
    2010-05
  • NCT01284556
    2016-04
  • NCT03650270
    2018-03-01
  • NCT03632915
    2019-12-31
  • 1 further recorded trial NCT03196466
    2023-06-15

At the median, Phenobarbital's trials enrolled 67 people — anything larger?


Median enrolment
67
Largest enrolment
753
Registered trials counted
32

What do 60 spontaneous reports say about Phenobarbital — and not say?


These are reports people sent to a regulator. They do not show the medicine caused the reaction. Nobody counted how many people took the medicine and reported nothing. The same event can be reported more than once, and many reports are incomplete. News coverage, lawsuits and new warnings change how often people report. A count is not a rate and not a risk.

Phenobarbital appears in spontaneous reports to regulators. Across the 10 most-reported reaction terms, 60 reaction mentions were counted: seizure 15; drug resistance 12; drug reaction with eosinophilia and systemic symptoms 6; heart injury 6. FAERS via Open Targets · CHEMBL149972 · 2026-06-24

Show the evidence
  • seizure
    15
  • drug resistance
    12
  • drug reaction with eosinophilia and systemic symptoms
    6
  • heart injury
    6
  • nystagmus
    6
  • blood lactic acid increased
    3
4 more recorded rows
  • cerebellar syndrome
    3
  • hypotonia
    3
  • intestinal ischaemia
    3
  • mucosal ulceration
    3

recorded 2026-06-24 · last checked 2026-09-04

Which 10 reactions does Phenobarbital's label not list?


blood lactic acid increased, cerebellar syndrome and drug reaction with eosinophilia and systemic symptoms and 7 more reported for Phenobarbital, absent from its label. FAERS via Open Targets · CHEMBL149972 · 2026-06-24

2 label terms; 10 reported and unlisted; b43c3611-24f6-4eaf-ac68-c2807f92ca98

Show the evidence
  • blood lactic acid increased
    count not stated
  • cerebellar syndrome
    count not stated
  • drug reaction with eosinophilia and systemic symptoms
    count not stated
  • drug resistance
    count not stated
  • heart injury
    count not stated
  • hypotonia
    count not stated
4 more recorded rows
  • intestinal ischaemia
    count not stated
  • mucosal ulceration
    count not stated
  • nystagmus
    count not stated
  • seizure
    count not stated

recorded 2026-06-24 · last checked 2026-09-04

Phenobarbital and CYP2B6, BCRP and CYP2C19: shared by which compounds?


CYP2B6, BCRP and CYP2C19 appear in Phenobarbital's recorded interaction sentences, 6 in all. DailyMed label · 8c7d0402-4977-4c25-bc4b-11db91339e9a · 2026-08-30

CYP2B6, CYP2B6, CYP2C19, CYP2C19, CYP2C8, CYP2C9; 25 shared nodes; clinical_pharmacology

Show the evidence

Interaction statement

  • clinical_pharmacology
    Transporter Systems: Phenobarbital is an inhibitor of BCRP, OAT1, OAT3, OCT2, OATP1B1, MATE1, and MATE2K.
  • clinical_pharmacology
    Phenobarbital is an inducer of CYP3A4, CYP2B6, and CYP2Cs [see Drug Interactions (7.1)] .
  • clinical_pharmacology
    In Vitro Studies Cytochrome P450 (CYP) Enzymes: Phenobarbital is an inhibitor of CYP2B6, CYP2C8, CYP2C9, CYP2C19, and CYP3A4.
  • clinical_pharmacology
    Metabolism Published literature reports that phenobarbital is primarily metabolized by CYP2C9 and to a lesser extent by CYP2C19, CYP2E1, and UGTs.
  • clinical_pharmacology
    At birth, expression of CYP2C9 is negligible, which results in the longer half-life in neonates compared to older populations in the published literature.
  • clinical_pharmacology
    Phenobarbital is not a substrate of OAT1, OAT3, OCT2, OATP1B1, OATP1B3, MATE1, or MATE2K transporters.

CYP2B6

  • FINGOLIMOD LAURYL SULFATE, TAFAMIDIS MEGLUMINE, Arimoclomol, Sofpironium, Bupropion, Golodirsen, Tinidazole, Naldemedine
  • FINGOLIMOD LAURYL SULFATE, TAFAMIDIS MEGLUMINE, Arimoclomol, Sofpironium, Bupropion, Golodirsen, Tinidazole, Naldemedine

CYP2C19

  • FINGOLIMOD LAURYL SULFATE, FOSAPREPITANT DIMEGLUMINE, TAFAMIDIS MEGLUMINE, Arimoclomol, Rasagiline, Golodirsen, Naldemedine, Etravirine
  • FINGOLIMOD LAURYL SULFATE, FOSAPREPITANT DIMEGLUMINE, TAFAMIDIS MEGLUMINE, Arimoclomol, Rasagiline, Golodirsen, Naldemedine, Etravirine
  • CYP2C8
    FINGOLIMOD LAURYL SULFATE, TAFAMIDIS MEGLUMINE, Arimoclomol, Golodirsen, Naldemedine, Methylnaltrexone, Lapatinib, Tivozanib

CYP2C9

  • FINGOLIMOD LAURYL SULFATE, FOSAPREPITANT DIMEGLUMINE, TAFAMIDIS MEGLUMINE, Arimoclomol, Rasagiline, Golodirsen, Tinidazole, Naldemedine
  • FINGOLIMOD LAURYL SULFATE, FOSAPREPITANT DIMEGLUMINE, TAFAMIDIS MEGLUMINE, Arimoclomol, Rasagiline, Golodirsen, Tinidazole, Naldemedine
  • FINGOLIMOD LAURYL SULFATE, FOSAPREPITANT DIMEGLUMINE, TAFAMIDIS MEGLUMINE, Arimoclomol, Rasagiline, Golodirsen, Tinidazole, Naldemedine
  • CYP2E1
    FINGOLIMOD LAURYL SULFATE, FOSAPREPITANT DIMEGLUMINE, Rasagiline, Tinidazole, Naldemedine, Methylnaltrexone, Alosetron, Metaxalone

CYP3A4

  • FINGOLIMOD LAURYL SULFATE, ERYTHROMYCIN LACTOBIONATE, FOSAPREPITANT DIMEGLUMINE, TAFAMIDIS MEGLUMINE, Arimoclomol, Beclometasone, Rasagiline, Sofpironium
  • FINGOLIMOD LAURYL SULFATE, ERYTHROMYCIN LACTOBIONATE, FOSAPREPITANT DIMEGLUMINE, TAFAMIDIS MEGLUMINE, Arimoclomol, Beclometasone, Rasagiline, Sofpironium
  • BCRP
    TAFAMIDIS MEGLUMINE, Arimoclomol, Ceftobiprole Medocaril, Deoxycholic acid, Golodirsen, Naldemedine, Eravacycline, Omadacycline

MATE1

  • TAFAMIDIS MEGLUMINE, Arimoclomol, Ceftobiprole Medocaril, Sofpironium, Golodirsen, Eravacycline, Prucalopride, Chenodeoxycholic acid
  • TAFAMIDIS MEGLUMINE, Arimoclomol, Ceftobiprole Medocaril, Sofpironium, Golodirsen, Eravacycline, Prucalopride, Chenodeoxycholic acid

MATE2-K

  • TAFAMIDIS MEGLUMINE, Arimoclomol, Sofpironium, Golodirsen, Eravacycline, Prucalopride, Chenodeoxycholic acid, Methylnaltrexone
  • TAFAMIDIS MEGLUMINE, Arimoclomol, Sofpironium, Golodirsen, Eravacycline, Prucalopride, Chenodeoxycholic acid, Methylnaltrexone

OAT1

  • TAFAMIDIS MEGLUMINE, Arimoclomol, Ceftobiprole Medocaril, Deoxycholic acid, Golodirsen, Naldemedine, Eravacycline, Prucalopride
  • TAFAMIDIS MEGLUMINE, Arimoclomol, Ceftobiprole Medocaril, Deoxycholic acid, Golodirsen, Naldemedine, Eravacycline, Prucalopride

OAT3

  • TAFAMIDIS MEGLUMINE, Arimoclomol, Ceftobiprole Medocaril, Deoxycholic acid, Golodirsen, Naldemedine, Pemetrexed, Eravacycline
  • TAFAMIDIS MEGLUMINE, Arimoclomol, Ceftobiprole Medocaril, Deoxycholic acid, Golodirsen, Naldemedine, Pemetrexed, Eravacycline

recorded 2026-08-30 · last checked 2026-09-04

Where do the label and the trials disagree about Phenobarbital?


"withdrawn" against "approved": withdrawal status vs register status for Phenobarbital.

REGISTER_SET, Drugs@FDA; 1 recorded pair

Show the evidence
  • REGISTER_SET CHEMBL40
    withdrawn; 2026-09-04
  • Drugs@FDA NDA215910
    approved; 2026-08-28
Where it is registered

Where it’s registered

Withdrawn; no reason is published (ChEMBL)

Identifiers, relations and other names

The exact record

ChEMBL id
CHEMBL149972
PubChem CID
12598276
CAS number
57-30-7
RxCUI
82077
InChIKey
DDBREPKUVSBGFI-UHFFFAOYSA-N
Also called
Phenobarbital sodium
Also called
Fenobarbital de sodio, Phenobarbital sod, Phenobarbital sodique, Phenobarbitalum natricum, Sezaby, Fenobarbital, Phenobarbital civ, pb, 2,4,6(1H,3H,5H)-Pyrimidinetrione, 5-ethyl-5-phenyl-, monosodium salt, PHENOBARBITAL SODIUM SALT [MI], PHENOBARBITAL SODIUM [EP MONOGRAPH], PHENOBARBITAL SODIUM [JAN]
Trade name
Gardenal sod, Gardenal, Luminal, Noptil, Phenobarbitone
Salt form
Gardenal sodium, Luminal sodium, Phenobarbital sodium salt, Sodium phenobarbital, Phenobarbital Oral Solution, PHENOBARBITAL ORAL, Phenobarbital Oral Solution / Sezaby
Development code
NSC-128143, NSC-9848
Component
Phenobarbital sodium
Sources (8)

Sources

2 more sources

ChEMBL 37 — CC BY-SA 3.0 Unported · ClinicalTrials.gov — US Government work · Open Targets 26.06 — CC0 · mixed register set; per-register licences in docs/specs/corpus-20k-sources.md · openFDA / DailyMed — US Government work

How these records are assembled · Which registers were checked

Index-quality checks
  • identity passed: no open identity hold
  • required summary fields resolved: 4 required field(s) not terminal: Why people use it, Best-supported result, Biggest unanswered question, Human evidence
  • public claims reviewed: 0 reviewed claim(s); drafts are never rendered
  • source coverage passed: 8 source rows
  • no critical contamination: no quarantine open
  • canonical metadata passed: slug and display name present
  • no raw internal fields: enforced by the copy-contract test over the rendered page

This is a record of evidence. It is not medical advice, and it does not say this substance suits you. Nothing here says any substance on RNAWiki is appropriate for a child.