Open-label clinical trial of rectally administered levetiracetam as supplemental treatment in dogs with cluster seizures

Background: Treatment options for at-home management of cluster seizures (CS) and status epilepticus (SE) are limited. The pharmacokinetics of levetiracetam (LEV) after rectal administration in both healthy and epileptic dogs has been investigated recently. Hypothesis/Objectives: To investigate the clinical efficacy of rectally administered LEV in preventing additional seizures in dogs presented for CS and SE. We hypothesized that rectal administration of LEV in addition to a standard treatment protocol would provide better control of seizure activity as compared with the standard treatment protocol alone. Animals: Fifty-seven client-owned dogs with CS or SE. Methods: Prospective open-label clinical trial. Patients included in the study were assigned to receive either a standard treatment protocol comprising IV/rectal diazepam and IV phenobarbital q8h (control group) or a standard treatment protocol in association with a single dose of 40 mg/kg LEV rectally (rectal LEV group). Dogs that experienced no additional seizures were defined as responders, whereas those that showed additional seizure activity were classified as nonresponders. Results: Twenty-one dogs were assigned to the rectal LEV group, and 36 to control group. Given the small number of cases of SE, statistical analysis was performed only on patients with CS. The response rate was 94% in the rectal LEV group and 48% in the control group (P <.001). Conclusions and Clinical Importance: Rectally administered LEV combined with a standard treatment protocol provided good control of seizure activity in patients with CS. The validity of these results should be confirmed in a double-blinded, placebo-controlled clinical trial.