Gabapentin
1-(aminomethyl)cyclohexaneacetic acid
Also known as: Neurontin Β· Aclonium Β· Equipax Β· Gantin Β· Gabarone Β· Neurostil Β· Progresse Β· CI-945 Β· GOE-3450 Β· Gabapentinum
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Dosing by species
π NA β North Americaπ EU β Europe
Dogs
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Ancillary therapy of refractory seizures | 10-20 mg/kg | PO | q6-8h | β | π NA |
| Ancillary therapy of refractory seizures | 10-30 mg/kg | PO | q8-12h | β | π NA |
| Ancillary therapy of refractory seizures | 25-60 mg/kg/day divided q6-8h | PO | q6-8h | β | π NA |
| Ancillary therapy of refractory seizures | 10 mg/kg | PO | q8h | 3 months | π NA |
| Ancillary therapy of refractory seizures | 10-30 mg/kg | PO | q8h | β | π NA |
| Adjunctive treatment of chronic or cancer pain | 3 mg/kg | PO | once a day | β | π NA |
| Analgesic | 1.25-10 mg/kg | PO | q24h | β | π NA |
| Analgesic | 5-10 mg/kg | PO | 2-3 times a day | β | π NA |
| Analgesic | 2.5-10 mg/kg (up to 15 mg/kg) | PO | 1-3 times a day | β | π NA |
| Adjunctive seizure therapy / Chronic pain | 10-20 mg/kg | PO | q6-8h | β | π EU |
- Ancillary therapy of refractory seizures: Author notes gabapentin is the least effective of the newer antiepileptic drugs, particularly in dogs.
- Ancillary therapy of refractory seizures: Author initially uses 10 mg/kg PO q8h.
- Ancillary therapy of refractory seizures: For uncontrolled seizures when phenobarbital and potassium bromide levels were therapeutic, or sub-therapeutic but had unacceptable side effects.
- Analgesic: Most VIN consultants recommend this dose.
- Adjunctive seizure therapy / Chronic pain: starting dose; incremental dose increases are recommended
Cats
| Indication | Dose | Route | Frequency | Duration | Region |
|---|---|---|---|---|---|
| Ancillary therapy of refractory seizures | 5-10 mg/kg | PO | q8-12h | β | π NA |
| Ancillary therapy of refractory seizures | 5 mg/kg | PO | three times daily | β | π NA |
| Ancillary therapy of refractory seizures | 10-30 mg/kg | PO | q8-12h | β | π NA |
| Analgesic | 1.25-10 mg/kg | PO | q24h | β | π NA |
| Adjunctive treatment of chronic or cancer pain | 3 mg/kg | PO | once a day | β | π NA |
| Adjunctive analgesia associated with neuropathic pain | 2.5-5 mg/kg | PO | q12h | β | π NA |
| Analgesic | 5-10 mg/kg | PO | 2-3 times a day | β | π NA |
| Analgesic | 50 mg (total dose) per cat | PO | 1-3 times a day | β | π NA |
| Adjunctive seizure therapy / Chronic pain | 5-10 mg/kg | PO | q8-12h | β | π EU |
- Adjunctive analgesia associated with neuropathic pain: Author starts at 5 mg/kg and increases (up to 10 mg/kg) if no effect seen in two hours. Wean off slowly. Reduce in renal insufficiency.
- Analgesic: Most VIN consultants recommend this dose.
- Adjunctive seizure therapy / Chronic pain: starting dose; incremental dose increases are recommended
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Overview
Gabapentin is a structural analogue of gamma-aminobutyric acid (GABA) widely utilized in veterinary medicine primarily for its neuropathic analgesic and anticonvulsant properties.
- Analgesia: Highly effective for chronic, maladaptive, and neuropathic pain (e.g., osteoarthritis, intervertebral disc disease, cancer pain). Often used as part of a multimodal analgesic protocol.
- Seizure Management: Used as an adjunctive antiepileptic drug (AED) for refractory or complex partial seizures, though its efficacy as a sole agent is limited.
- Behavioral/Anxiolytic: Increasingly used off-label in cats and dogs to reduce fear, anxiety, and stress (FAS) prior to veterinary visits or stressful events.
Mechanism of action
Despite its name, gabapentin does not bind to GABA receptors, nor does it affect GABA synthesis or uptake.
- Binds selectively to the βΞ±2-Ξ΄ (alpha-2-delta) subunitβ of βvoltage-gated calcium channels (CaV)β in the central nervous system.
- Inhibition of Calcium Influx β Decreased presynaptic calcium currents.
- Reduced Neurotransmitter Release β Suppresses the release of excitatory neurotransmitters including glutamate, substance P, and norepinephrine in the dorsal horn of the spinal cord.
- This dampens neuronal excitability, effectively preventing allodynia (pain from non-noxious stimuli) and hyperalgesia (exaggerated pain response).
Safety & warnings
Contraindications
- Hypersensitivity to gabapentin
- Use of xylitol-containing human oral solutions in dogs
- Oral solutions containing xylitol (highly toxic to dogs)
Adverse effects
- Ataxia
- Dizziness (humans)
- Somnolence
- Peripheral edema (humans)
- Withdrawal-precipitated seizures (if abruptly discontinued)
- Increased rate of pancreatic adenocarcinoma (noted in male rats)
- Mild sedation
- False-positive urinary protein tests (reported in humans)
- Hepatic toxicity (rare, reported in humans)
Precautions
WARNING: Commercially available human oral solutions (e.g., Neurontin) often contain xylitol (up to 300 mg/mL), which is highly toxic to dogs, causing severe hypoglycemia and hepatotoxicity. Avoid use in dogs.
- Renal Insufficiency: Eliminated primarily via the kidneys. Use with caution and consider dosage adjustments in patients with renal impairment. Dogs partially metabolize the drug (30-40%), so mild to moderate renal dysfunction may not require adjustment.
- Withdrawal: Abrupt discontinuation can lead to withdrawal-precipitated seizures. Taper the dose gradually when discontinuing, especially in epileptic patients.
- Laboratory Alterations: May cause false-positive urinary protein readings on Ames N-Multistix SG dipstick tests. Use a sulfosalicylic acid precipitation test instead.
Drug interactions
Oral antacids given concurrently may decrease oral bioavailability of gabapentin by 20%; separate doses by at least 2 hours.
Co-administration may increase gabapentin AUC and efficacy/adverse effects. Gabapentin may reduce hydrocodone AUC, potentially reducing its effectiveness.
May increase gabapentin levels.
Reduced absorption of gabapentin from the GI tract. Administer gabapentin at least 2 hours after antacids.
Reduced renal clearance of gabapentin (not considered clinically important).
Monitoring
- Clinical efficacy (reduction in pain scores or seizure frequency)
- Adverse effects (sedation, ataxia)
- Renal function (in patients with pre-existing disease)
- Clinical response (pain scores, seizure frequency)
- Renal and hepatic function in compromised patients
Pharmacokinetics
Half-life
Absorption
Dogs: Oral bioavailability ~80% at 50 mg/kg. Peak plasma levels at 2 hours. Cats: Bioavailability ~90% (high interpatient variation 50-120%). Peak levels at 100 minutes. Horses: Rapidly absorbed, peak levels within 2 hours.
Distribution
Cats: Volume of distribution is relatively low (Vdss 0.65 L/kg). Humans: Minimally bound to plasma proteins; CSF levels are ~20% of plasma levels.
Metabolism
Dogs: Partially metabolized (30-40%) to N-methyl-gabapentin. Humans: Not significantly metabolized.
Elimination
Primarily via renal routes (excreted unchanged in urine in humans). Cats: Clearance ~3 mL/min/kg.
Overdose
In humans, massive overdoses (up to 49 grams) have been reported without fatality.
- Clinical Signs: Ataxia, lethargy, somnolence, vomiting, and diarrhea.
- Xylitol Toxicity Risk: The human oral solution contains 300 mg/mL of xylitol. Doses as low as 0.33 mL/kg of this solution can cause severe hypoglycemia or hepatotoxicity in dogs.
- Treatment: Primarily supportive. General decontamination (emesis, activated charcoal, cathartics) if caught early. The drug can be removed via hemodialysis. If xylitol toxicity is suspected secondary to the human liquid formulation, aggressive treatment for hypoglycemia and liver protection is required; contact an animal poison control center.
Available products
Formulations
- Capsules
- Tablets
- Compounded Oral Suspension
- 100 mg capsule
- 300 mg capsule
- 400 mg capsule
- 600 mg film-coated tablet
- 800 mg film-coated tablet
- 50 mg/ml oral solution
Human-labeled
- Gabapentin Oral Capsules & Tablets: 100 mg, 300 mg, 400 mg, 600 mg, 800 mg (Neurontin, generic)
- Gabapentin Oral Solution: 250 mg/5mL (50 mg/mL) (Neurontin) - Contains xylitol! Use with caution in dogs.
- Neurontin 100 mg, 300 mg, 400 mg capsules
- Neurontin 600 mg, 800 mg film-coated tablets
- Neurontin 50 mg/ml oral solution
Regulatory status
POM CD Schedule 3
No regulatory data for: πΊπΈ US Β· ππ° HK Β· πΉπΌ TW Β· π―π΅ JP Β· π°π· KR Β· π¦πΊ AU
Storage & stability
Capsules and tablets: Store at room temperature (25Β°C / 77Β°F); excursions permitted to 15-30Β°C. Oral liquid: Store in the refrigerator at 2-8Β°C (36-46Β°F). Compounded suspensions are most stable at pH 5.5-6.5.
Client information
βWhat is Gabapentin?β Gabapentin is a medication used to treat chronic nerve pain and, less commonly, to help control seizures. It is also frequently used to reduce fear and anxiety before stressful events like vet visits.
How to Give This Medication
- Can be given with or without food.
- Never give the human liquid form (Neurontin) to your dog unless specifically compounded by a veterinary pharmacy, as it contains xylitol, an artificial sweetener that is highly toxic and potentially fatal to dogs.
What to Watch For
- The most common side effects are βsleepiness (sedation)β and βwobbliness (ataxia)β. These effects are usually mild and often improve as your pet gets used to the medication.
- Contact your veterinarian if your pet seems excessively drowsy or uncoordinated.
Important Notes
- If your pet is taking gabapentin for seizures, do not stop the medication abruptly, as this can trigger severe withdrawal seizures. Always consult your vet before changing the dose.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturerβs current label.