Carbamazepine

What is this medication for?

• 3rd-line: aggression (esp. refractory), psychomotor seizures, neuropathic pain — sporadic case-report efficacy only
• Photic head-shaking not responding to cyproheptadine

How is it given?

Give exactly as your veterinarian prescribed — never change the dose or stop on your own unless your veterinarian has told you to.

• The pharmacokinetic lesson: right target (sodium channels for neuropathic pain/aggression), wrong canine clearance profile — why it never became a veterinary staple despite human neurology success.

What if I miss a dose?

• Give it as soon as you remember — unless it is almost time for the next dose (then skip the missed one; never double up).
• Call your clinic if you miss more than one dose in a row.

Side effects — what should I watch for?

Effects listed as common in this handout

• Sedation, wobbliness/unsteadiness, stomach/intestinal upset (class extrapolation) (Little veterinary data)

Worth a phone call to your veterinarian

• Agranulocytosis/aplastic low red blood cell counts (human idiosyncrasy) (The human monitoring burden)
• Perrin flags: MAOIs + bone marrow suppression contraindications (Class warnings)

⚠️ Contact your veterinarian or an emergency clinic IMMEDIATELY if you notice

• Trouble breathing, collapse, seizures, severe vomiting or diarrhea, facial swelling, or pale gums

Before starting (or refilling), tell your veterinarian if your pet:

• has or has had: MAOI use; bone marrow suppression history (Perrin)
• has or has had: Hepatic disease (auto-inducer); cardiac conduction; 3rd-line only until better veterinary data

• is pregnant, nursing, or used for breeding
• is taking any other medications, supplements, or flea/tick products, including:
  • Many — potent CYP inducer (phenobarbital-like profile)
  • MAOIs
  • Clonazepam/valproate etc. (human combos)

Storage and handling

Room temperature; SR formulations preferred where used.

Good to know

• The pharmacokinetic lesson: right target (sodium channels for neuropathic pain/aggression), wrong canine clearance profile — why it never became a veterinary staple despite human neurology success.
• Keep as 3rd-line after SSRIs/TCAs fail; Perrin dosing (dog 4–8, cat 2–6 mg/kg every 12 hours) is the practical reference.