Pregabalin
Pregabalin is a structural analog of GABA, similar to gabapentin, used primarily as an **anticonvulsant** and **neuropathic pain analgesic** in veterinary medicine. * **Key Uses**: Adjunctive therapy for refractory or complex partial seizures, and management of chronic/neuropathic pain. * **Clinical Pearl**: It is considered 3-10 times more potent than gabapentin, allowing for lower dosing volumes, which can be advantageous in small patients. * **Safety Profile**: Generally well-tolerated, though sedation and ataxia are the most common dose-dependent side effects. Currently, there is limited but growing information regarding its safety and efficacy in dogs and cats.
Mechanism: Pregabalin is a structural analog of the inhibitory neurotransmitter **gamma-aminobutyric acid (GABA)**. Despite its structure, it does not bind directly to GABA receptors. * Binds with high affinity to the **alpha-2-delta (α2δ) subunit** of **voltage-gated calcium channels (CaV)** in the central nervous system. * Binding → Decreased calcium influx at nerve terminals → Inhibition of the release of excitatory neurotransmitters (e.g., **glutamate**, **substance P**, **norepinephrine**). * This reduction in excitatory neurotransmission produces its **analgesic**, **anticonvulsant**, and **anxiolytic** effects.
Dosing by species
- Seizure disorders (anecdotal) · 1-2 mg/kg PO q12h · PO · q12h · Most commonly mentioned anecdotal dose.
- Seizure disorders (PK theory) · 1-2 mg/kg PO twice daily · PO · q12h · Theorized reasonable starting dose based on single-dose PK study.
- Neuropathic pain and seizures (extrapolated from PK study) · 4 mg/kg PO twice daily · PO · q12h · Would produce plasma levels within the extrapolated therapeutic range.
- Seizure disorders · 3-4 mg/kg PO every 8 hours · PO · q8h · To minimize side effects, initially start on 2 mg/kg and increase by 1 mg/kg each week until target dose is reached.
- Seizure disorders · gradually increased from 2 mg/kg PO to 3-4 mg/kg q8-12h · PO · q8-12h · Gradual increase needed to minimize sedation.
- Refractory seizures (adjunct therapy) · 2 mg/kg q8-12h, increasing 1 mg/kg/dose each week to a total of 3-4 mg/kg · PO · q8-12h · Used as a third anticonvulsant if control cannot be obtained with phenobarbital and bromides.
Doses are a clinical reference for licensed veterinary professionals. Always confirm against the current label and the individual patient.
Routes of administration
Contraindications
- Hypersensitivity to pregabalin
- Pregnant animals (toxicity demonstrated in experimental studies)
- Abrupt discontinuation
Adverse effects
- Sedation
- Ataxia
- Somnolence
- Dizziness
- Difficulty with concentration/attention/memory
- Blurred vision
- Dry mouth
- Peripheral edema
- Constipation
- Weight gain
- Syncope
- Congestive heart failure
- Renal failure (reversible)
- Rhabdomyolysis
- Hypersensitivity reactions (angioedema, rash, blisters, wheezing)
- Decreased platelet production
- Increased creatine kinase
Drug interactions
- ACE Inhibitors (e.g., benazepril, enalapril) · In humans, coadministration may increase risks of edema and hives.
- CNS Depressants · May cause additive CNS depression.
- NSAIDs (e.g., ketorolac, naproxen) · In humans, cited as possibly reducing anticonvulsant effectiveness, though substantive evidence is weak.
Monitoring
- Efficacy (seizure frequency, pain scores)
- Adverse effects (sedation, ataxia)
- Seizure frequency and severity
- Pain scores
- Renal function (BUN, creatinine, USG)
- Hepatic enzyme activities (during prolonged therapy)
Overdose
There is limited experience with overdoses of pregabalin in veterinary medicine. One human ingested 8 grams without significant effect. There is no specific antidote for overdose. Standard decontamination protocols can be employed if indicated. Contact an animal poison center for more information.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.