Uses/Indications: Used as both primary and adjunctive therapy to control seizures in dogs who are not adequately controlled on phenobarbital alone (when steady state trough phenobarbital concentrations are > 30mcg/ml for one month). Historically, it is only used alone when patients are suffering from phenobarbital hepatotoxicity, and occasionally may be considered as a drug of first choice.
Studies: 1. In a retrospective study, the response to adding oral potassium bromide to phenobarbital administration was studied in 23 refractory idiopathic epileptic canines, with the effects of bromide therapy evaluated for mean of 15 months with 17 dogs (74%) followed for 12 or more months. The response to bromide therapy was associated with a reduction in the total number of seizures in 83% of the dogs. For those followed for 1 year after bromide therapy, there was a 53% reduction in the number of seizure compared to the previous 12 months and owners reported a 65% decrease in seizure intensity. Seizure-free status was obtained in 26% of the dogs followed.
Adverse Effects: transient sedation (lasting up to 3 weeks), polyphagia, polydipsia, polyuria, anorexia, vomiting, constipation.
Toxicity: profound sedation to stupor, ataxia, tremors, and hind limb paresis
Dosing: Loading dose: 400-600mg/kg/day divided BID for 2 to 3 days
Maintenance dose: 22-30mg/kg/day if using phenobarbital; 70-80mg/kg/day as a single agent
**Loading dose should be considered if reaching a therapeutic level with rapidity is important**
Monitoring Parameters: Efficacy/Toxicity, Serum Levels: measure trough serum levels at 30 days, 120 days, and every 6 months after initiation (suggested therapeutic levels in dogs range from 1 to 2mg/ml)