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Meds A-Z

Phenobarbital

Detailed information about Phenobarbital

Official label facts Owner quick guide first Marketing clearly labeled
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Pet Owner Quick Guide

Start here: what this medicine is for, what it does, and when it's usually needed.

Usually used for:

Conditionally approved for the control of seizures associated with idiopathic epilepsy in dogs.

What it does:

Anti-seizure medication used for epilepsy and seizure disorders.

When it's needed:

Use caution with liver disease.

Call your vet sooner if you notice:

  • Use caution with liver disease.

Commonly reported reactions:

  • (1 reports)
  • (1 reports)
  • (1 reports)

What to ask your vet today:

  • Is this medicine the right fit for my pet’s current symptoms?
  • Which warning signs mean I should call back right away?
  • How should I handle missed doses or refusal to take the medicine?
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Phenobarbital

Phenobarbital

Drug type: Generic ingredient • Branded profile FDA branded products available

Species: Both

Manufacturer: MSK

Quick Facts

Official label facts first, then secondary summaries. Marketing content is separated below.

Species: Both
Manufacturer: MSK
Form: Tablet
Identifiers:
NADA: 141578 NDC Package: 64950-541-01 NDC Package: 64950-541-10 NDC Package: 64950-542-01 NDC Package: 64950-542-10 NDC Package: 64950-543-01 NDC Package: 64950-543-10 NDC Package: 64950-544-01 NDC Package: 64950-544-10 NDC Package: 64950-560-01 NDC Package: 64950-560-10 NDC Package: 64950-561-01 NDC Package: 64950-561-10 NDC Package: 64950-562-01 NDC Package: 64950-562-10 NDC Package: 64950-563-01 NDC Package: 64950-563-10 NDC Product: 64950
Source metadata:

Warnings / Contraindications

Use caution with liver disease.

  • High: Use caution with liver disease.
Source metadata:

Adverse Reactions

Snapshot first, detailed rows second. This section summarizes signal data and is not a diagnosis.

Tap or hover a reaction to see what it means in plain language.

Tracked signals
32
Reported cases
32
Serious reports
13
Species represented
2
Most Reported Reactions
Reaction Cases Species Serious cases
1 Dog 1
1 Dog 1
1 Dog 1
1 Cat 1
1 Dog 1
1 Cat 1
1 Dog 1
1 Dog 1

Species coverage: Dog (17) Cat (15)

View detailed reaction table
Reaction Species Seriousness Frequency Reports
Dog Non-serious - 1
Cat Non-serious - 1
Dog Non-serious - 1
Dog Non-serious - 1
Dog Non-serious - 1
Cat Serious - 1
Dog Non-serious - 1
Cat Non-serious - 1
Dog Serious - 1
Dog Non-serious - 1
Cat Non-serious - 1
Cat Serious - 1
Dog Serious - 1
Cat Serious - 1
Dog Serious - 1
Dog Serious - 1
Cat Non-serious - 1
Cat Serious - 1
Dog Serious - 1
Cat Non-serious - 1
Dog Non-serious - 1
Cat Non-serious - 1
Cat Non-serious - 1
Cat Serious - 1
Dog Serious - 1
Cat Non-serious - 1
Dog Serious - 1
Dog Serious - 1
Dog Non-serious - 1
Dog Non-serious - 1
Cat Non-serious - 1
Cat Non-serious - 1
Source metadata:

Storage & Handling

Store at room temperature; keep secured.

Source metadata: No source yet.

Documents

Official label facts are separated from secondary summaries.

Official documents: 2 • Secondary summaries: 0

Secondary summaries

No source yet.

Promotional Materials (Marketing)

This content is marketing material and not clinical guidance.

No marketing assets are linked yet.

No source yet.

Source metadata: No source yet.
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Technical appendix (vet reference)

Canonical medication sections are above. This legacy block remains available for deeper cross-reference without cluttering the primary workflow.

At a Glance

Quick facts and links to official labeling and safety signals.

Data freshness
  • Medication catalog: Source PetWisePlus | Refreshed Feb 12, 2026, 7:40 PM UTC
  • Animal Drugs @ FDA: Source FDA | Refreshed Feb 16, 2026, 11:00 AM UTC
    Applications/products are imported from FDA export data.
  • Animal Drugs @ FDA previews: Source FDA | Refreshed Feb 9, 2026, 3:05 AM UTC
    Label highlights/doc links are fetched from FDA preview endpoints.
  • Animal Drug Product Listing Directory (NDC): Source FDA | Refreshed Feb 16, 2026, 11:00 AM UTC
    Package/product NDCs from FDA’s electronic listing directory (XLS).
  • openFDA reaction terms: Source FDA openFDA | Refreshed Feb 16, 2026, 11:02 AM UTC
  • openFDA case summaries: Source FDA openFDA | Refreshed Feb 9, 2026, 3:19 AM UTC
Official (FDA)
Identity: Generic ingredient • FDA branded products available
Official FDA brands: FIDOQUEL™-CA1
Case-reported brands (openFDA): MSK
Catalog species: Both FDA-labeled species: Dog
Rx/OTC: RX
Form/route: Tablet Oral
Applications: C 141-578
Documents: 1 (FOI: 1) • SPL: 1 Label highlights Official documents
Safety (openFDA)
Top reactions: Dog 56 Cat 43 View
Case summaries: 10 (showing 8) View
openFDA reports are unverified and do not prove causation.

Explore
Related conditions: Seizures (idiopathic/structural)
Linked using: Fda_Label (0.95)

Diagnosis Codes

Diagnosis-code mappings are not available for this medication yet.

Counseling and Monitoring Highlights

Global Pet owner/Vet mode is controlled in the header. This section avoids duplicate in-page persona tabs.

Owner-facing counseling points
  • Use caution with liver disease. (Contraindication, High)
Top reaction signals
Anaemia NOS (1) Blood in vomit (1) Decreased haematocrit (1) Decreased haemoglobin (1) Decreased red blood cell count (1) Diarrhoea (1) Elevated serum alkaline phosphatase (ALP) (1) Emesis (multiple) (1) Fever (1) Gait abnormality (1) Hyperglycaemia (1) Inappetence (1) Intentional misuse (1) Ketosis (1) Lack of efficacy - NOS (1) Lethargy (see also Central nervous system depression in Neurological) (1)

Identifiers & Packages

Normalized identifiers (NDC/NADA/ANADA) and package metadata from regulator listings.

Identifiers
NADA: 141578 NDC Package: 64950-541-01 NDC Package: 64950-541-10 NDC Package: 64950-542-01 NDC Package: 64950-542-10 NDC Package: 64950-543-01 NDC Package: 64950-543-10 NDC Package: 64950-544-01 NDC Package: 64950-544-10 NDC Package: 64950-560-01 NDC Package: 64950-560-10 NDC Package: 64950-561-01 NDC Package: 64950-561-10 NDC Package: 64950-562-01 NDC Package: 64950-562-10 NDC Package: 64950-563-01 NDC Package: 64950-563-10 NDC Product: 64950
Package NDC Product NDC Form / Route Status
64950-541-01 64950 -
64950-541-10 64950 -
64950-542-01 64950 -
64950-542-10 64950 -
64950-543-01 64950 -
64950-543-10 64950 -
64950-544-01 64950 -
64950-544-10 64950 -
64950-560-01 64950 -
64950-560-10 64950 -
64950-561-01 64950 -
64950-561-10 64950 -
64950-562-01 64950 -
64950-562-10 64950 -
64950-563-01 64950 -
64950-563-10 64950 -

Enriched Documents

Documents are tiered by source trust: Official, Clinical, Manufacturer, Marketing.

Data Sources & Revision History

Every non-trivial field is expected to include provenance and update timestamps.

Official 4 Clinical 1 Manufacturer 0 Marketing 0
Current Field Facts
  • storage_handling: Store at room temperature; keep secured. (Clinical, 2026-02-12)
  • contraindications: Use caution with liver disease. (Official, 2026-02-12)
  • side_effects: Sedation, increased thirst/urination, increased appetite. Long-term: liver enzyme changes. (Official, 2026-02-12)
  • usage: Anti-seizure medication used for epilepsy and seizure disorders. (Official, 2026-02-12)
Recent Revisions
  • side_effects updated 2026-02-12 19:40 by etl_backfill • Backfilled from existing medication fields
  • contraindications updated 2026-02-12 19:40 by etl_backfill • Backfilled from existing medication fields
  • usage updated 2026-02-12 19:40 by etl_backfill • Backfilled from existing medication fields

FDA Products & Applications (Animal Drugs @ FDA)

Official sponsor/proprietary-name/application-status records linked by active ingredient.

Product Sponsor Application Status Published
FIDOQUEL™-CA1
RX
Phenobarbital
Tablet Oral
Genus Lifesciences Inc. C 141-578 Approved Jun 3, 2024

Data source: FDA Animal Drugs @ FDA (public search export).

What It's For (FDA Label Highlights)

Extracted from FDA Animal Drugs @ FDA product labeling. Always confirm details with your veterinarian.

Species: Dog, No Use Class Stated Or Implied
Composition / specifications
15, 16.2, 30, 32.4, 60, 64.8, 97.2, or 100 mg per tablet
Dogs
Indication

Conditionally approved for the control of seizures associated with idiopathic epilepsy in dogs.

Dosage

Administer phenobarbital as tablets given orally twice a day at the minimum dosage of 2.5 mg per kilogram of body weight (mg/kg) and may be titrated to effect to a maximum dosage of 5 mg/kg. The dosage of phenobarbital tablets should be adjusted based on monitoring the clinical response of the individual patient.

Limitations

FDA page: Open in Animal Drugs @ FDA

Official Documents (FDA)

Direct links to FDA-hosted PDFs and SPL packages (when available).

Documents
SPL Packages

FDA page: Open in Animal Drugs @ FDA

Usage

Anti-seizure medication used for epilepsy and seizure disorders.

Source: FDA Animal Drugs @ FDA • Reference

Contraindications

Use caution with liver disease.

Side Effects

Sedation, increased thirst/urination, increased appetite. Long-term: liver enzyme changes.

Source: FDA openFDA • Reference

Top Reported Reactions (openFDA)

Aggregated reaction terms from FDA openFDA reports (not verified; does not prove causation).

Dog
Digestive
Vomiting (94) Diarrhea (52)
Neurologic
Seizure NOS (362) Tiredness (lethargy) (92) Unsteady walking (ataxia) (57) Increased seizure frequency (56) Tiredness (lethargy) (1) Tiredness (lethargy) (1) Tiredness (lethargy) (1) Tiredness (lethargy) (1) Tiredness (lethargy) (1) Tiredness (lethargy) (1)
Effectiveness
Lack of efficacy - NOS (1) Lack of efficacy - NOS (1) Lack of efficacy - NOS (1) Lack of efficacy - NOS (1) Lack of efficacy - NOS (1) Lack of efficacy - NOS (1)
Other
Death by euthanasia (65) Death (53) Panting (2) Panting (2) Panting (2) Panting (2) Panting (2) Panting (2) Fever (1) Fever (1) Fever (1) Fever (1) Fever (1) Fever (1) Gait abnormality (1) Gait abnormality (1) Gait abnormality (1) Gait abnormality (1) Gait abnormality (1) Gait abnormality (1) Intentional misuse (1) Intentional misuse (1) Intentional misuse (1) Intentional misuse (1) Intentional misuse (1) Intentional misuse (1) Product label issues (1) Product label issues (1) Product label issues (1) Product label issues (1) Product label issues (1) Product label issues (1) Systemic disorder NOS (1) Systemic disorder NOS (1) Systemic disorder NOS (1) Systemic disorder NOS (1) Systemic disorder NOS (1) Systemic disorder NOS (1)
Cat
Digestive
Vomiting (9) Diarrhea (1) Diarrhea (1) Diarrhea (1) Diarrhea (1) Diarrhea (1) Diarrhea (1)
Skin & allergy
Twitching (10)
Neurologic
Seizure NOS (22) Unsteady walking (ataxia) (8) Tiredness (lethargy) (7) Seizure NOS (1) Seizure NOS (1) Seizure NOS (1) Seizure NOS (1) Seizure NOS (1) Seizure NOS (1)
Behavior
Behavioral disorder (unspecified) (7)
Other
Death by euthanasia (13) Weight loss (8) Ketosis (2) Ketosis (2) Ketosis (2) Ketosis (2) Ketosis (2) Inappetence (1) Inappetence (1) Inappetence (1) Inappetence (1) Inappetence (1) Inappetence (1) Ketosis (1) Pancreatitis NOS (1) Pancreatitis NOS (1) Pancreatitis NOS (1) Pancreatitis NOS (1) Pancreatitis NOS (1) Pancreatitis NOS (1) Weight loss (1) Weight loss (1) Weight loss (1) Weight loss (1) Weight loss (1)

Data source: FDA openFDA Animal & Veterinary adverse event reports.

Adverse Event Case Summaries (openFDA)

These are individual FDA adverse event reports. They are unverified and do not prove the medication caused the reaction.

Dog, ['Weimaraner', 'Retriever - Labrador'], Male, 14 year, 26.3 kilogram • Drug: MSK, Unknown • Reactions: Gait abnormality, Walking difficulty, Unsteady gait, Product label issues • Outcome: Ongoing

  • Report ID: USA-USFDACVM-2025-US-054553
  • Serious AE: No
  • Treated For AE: No
  • Sex: Male
  • Age: 14.00 Year
  • Weight: 26.300 Kilogram
  • Case-reported brand: MSK
  • Case-reported manufacturer: MSK
  • Route: Unknown
Reactions Reported:
Gait abnormality Walking difficulty Unsteady gait Product label issues
Outcomes: Ongoing

Dog, Pekingese, Male, 11 year, 9.208 kilogram • Drug: MSK, Unassigned, Unknown • Reactions: Panting, Fever • Outcome: Ongoing

  • Report ID: USA-USFDACVM-2025-US-055149
  • Serious AE: Yes
  • Treated For AE: Yes
  • Sex: Male
  • Age: 11.00 Year
  • Weight: 9.208 Kilogram
  • Case-reported brand: MSK
  • Case-reported manufacturer: MSK
  • Route: Unknown
  • Form: Unassigned
Reactions Reported:
Panting Fever
Outcomes: Ongoing

Dog, Dachshund (unspecified), Female, 9 year, 7.711 kilogram • Drug: MSK, Oral, Dose: 1.50 tablet per 2 dose, Frequency: 1 per day • Reactions: Tremors, Tiredness (lethargy), Panting, Twitching, Systemic disorder NOS • Outcome: Recovered/Normal

  • Report ID: USA-USFDACVM-2025-US-055213
  • Serious AE: Yes
  • Treated For AE: Yes
  • Sex: Female
  • Age: 9.00 Year
  • Weight: 7.711 Kilogram
  • Case-reported brand: MSK
  • Case-reported manufacturer: MSK
  • Route: Oral
  • Dose: 1.50 tablet per 2 dose
  • Frequency: 1 per day
Reactions Reported:
Tremors Tiredness (lethargy) Panting Twitching Systemic disorder NOS
Outcomes: Recovered/Normal

Dog, Bulldog - French, Male, 6 year, 16.5 kilogram • Drug: MSK, Unassigned, Oral • Reactions: Lack of efficacy - NOS, Intentional misuse • Outcome: Ongoing

  • Report ID: USA-USFDACVM-2025-US-053288
  • Serious AE: Yes
  • Treated For AE: Yes
  • Sex: Male
  • Age: 6.00 Year
  • Weight: 16.500 Kilogram
  • Case-reported brand: MSK
  • Case-reported manufacturer: MSK
  • Route: Oral
  • Form: Unassigned
Reactions Reported:
Lack of efficacy - NOS Intentional misuse
Outcomes: Ongoing

Cat, Maine Coon, Male, 12 year, 11 kilogram • Drug: MSK, Tablet, Unknown • Reactions: Diarrhea, Inappetence, Ketosis, Seizure NOS, Pancreatitis NOS • Outcome: Ongoing

  • Report ID: USA-USFDACVM-2025-US-050891
  • Serious AE: Yes
  • Treated For AE: No
  • Sex: Male
  • Age: 12.00 Year
  • Weight: 11.000 Kilogram
  • Case-reported brand: MSK
  • Case-reported manufacturer: MSK
  • Route: Unknown
  • Form: Tablet
Reactions Reported:
Diarrhea Inappetence Ketosis Seizure NOS Pancreatitis NOS
Outcomes: Ongoing

Cat, ['Maine Coon', 'Cat (unknown)'], Male, 11.5 year, 6.6 kilogram • Drug: MSK, Unknown • Reactions: Weight loss, Ketosis • Outcome: Outcome Unknown

  • Report ID: USA-USFDACVM-2025-US-048528
  • Serious AE: No
  • Treated For AE: No
  • Sex: Male
  • Age: 11.50 Year
  • Weight: 6.600 Kilogram
  • Case-reported brand: MSK
  • Case-reported manufacturer: MSK
  • Route: Unknown
Reactions Reported:
Weight loss Ketosis
Outcomes: Outcome Unknown

Cat, Domestic Longhair, Female, 6.4 kilogram • Drug: MSK, Unknown, Dose: 7.50 Milligram per animal, Frequency: 12 per hour • Reactions: Ketosis, Weight gain, Hyperglycaemia • Outcome: Ongoing

  • Report ID: USA-USFDACVM-2025-US-048417
  • Serious AE: No
  • Treated For AE: No
  • Sex: Female
  • Weight: 6.400 Kilogram
  • Case-reported brand: MSK
  • Case-reported manufacturer: MSK
  • Route: Unknown
  • Dose: 7.50 Milligram per animal
  • Frequency: 12 per hour
Reactions Reported:
Ketosis Weight gain Hyperglycaemia
Outcomes: Ongoing

Dog, Siberian Husky, Male, 11 year, 26.7 kilogram • Drug: MSK, Unknown • Reactions: Anaemia NOS, Decreased haematocrit, Decreased red blood cell count, Decreased haemoglobin, Elevated serum alkaline phosphatase • Outcome: Ongoing

  • Report ID: USA-USFDACVM-2025-US-047727
  • Serious AE: No
  • Treated For AE: No
  • Sex: Male
  • Age: 11.00 Year
  • Weight: 26.700 Kilogram
  • Case-reported brand: MSK
  • Case-reported manufacturer: MSK
  • Route: Unknown
Reactions Reported:
Anaemia NOS Decreased haematocrit Decreased red blood cell count Decreased haemoglobin Elevated serum alkaline phosphatase
Outcomes: Ongoing

Data source: FDA openFDA Animal & Veterinary adverse event reports.

Overdose Information

No approved overdose-management text is linked yet. If overdose is suspected, contact a veterinarian or emergency clinic immediately.

Storage & Handling

Store at room temperature; keep secured.

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This medication has not been reviewed by a veterinarian yet.