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May/June 2014 Today's Veterinary Practice 35 THe CanIne SeIzuRe PaTIenT: FouR IMPoRTanT QueSTIonS | tvpjournal.com Although studies are lacking, administration of an extra dose of maintenance AED and initiation of a novel AED for a short period of time (pulse therapy) is advised to control cluster seizures and status epilepticus (Table 4). I advise owners to give a dose of AED used for pulse therapy between seizures to assess side effects, and deter- mine best tolerated dose, prior to using the medication in the post-ictal period. Other Types of Therapy. Intranasal (IN), subcutaneous (SC), intramuscular (IM), and rectal AED administration have been advocated when (Table 5): • Patient is unable to swallow • Rapid cessation of seizure activity is required • Intravenous (IV) route is unavailable. I advise owners to give levetiracetam (60 mg/kg SC) plus midazolam (0.2 mg/kg IM) or diazepam injectable solu- tion (2 mg/kg by rectum). n aeD = anti-epileptic drug; CSF = cerebrospinal fluid; eeG = electroencephalography; Ie = idiopathic epilepsy; IM = in- tramuscular; In = Intranasal; IV = intravenous; MRI = mag- netic resonance imaging; Mue = meningoencephalitis of unknown etiology; SC = subcutaneous References 1. Podell M, Fenner wr, Powers Jd. Seizure classification in dogs from a nonreferral-based population. JAVMA 1995; 206(11):1721-1728. 2. Fisher rS, van Emde Boas w, Blume w, et al. Epileptic seizures and epilepsy: definitions proposed by the international League against Epilepsy (iLaE) and the international Bureau for Epilepsy (iBE). Epilepsia 2005; 46(4):470-472. 3. hardy BT, Patterson EE, Cloyd JM, et al. double-masked, placebo- controlled study of intravenous levetiracetam for the treatment of status Table 4. aeD Pulse Therapy DRUG DOSE INDICATIONS PULSE THERAPY Gabapentin 10–30 mg/kg Po Q 8 H For as long as patient is at risk for more seizures Phenobarbital 4–10 mg/kg Po after every seizure (and/or clorazepate); administer up to Q 1 H, not to exceed 30 mg/kg within 12 H Clorazepate 0.5–1 mg/kg Po after every seizure (and/or phenobar- bital) OTHER Acepromazine 0.5–1 mg/kg Po 30 To reduce post- ictal confusion and prevent stress- induced seizures; second dose (0.5 mg/kg) can be given in 1 H if confusion not controlled Bromide Avoid for pulse therapy due to its side effects and long elimination half-life Table 5. other aeD Rescue Therapies DRUG DOSE INDICATIONS Diazepam 0.5 mg/kg In or 2 mg/kg per rectum (injectable solution) • In injections reach more rapid, more consistent, and longer lasting serum concentrations than rectal administration 31 • Rectal suppository formulations have unfavorable absorption; not recommended for emergency treatment 32 Levetiracetam 60 mg/kg SC or 60 mg/kg (undiluted) IV bolus • Reaches therapeutic concentrations ≤ 15 min and lasts 7 H; currently my at-home therapy of choice 33 • IV bolus to rapidly achieve useful serum concentrations without seda- tion 34 Midazolam 0.2 mg/kg IM or In • Can be used instead of diazepam AED Monitoring Serum drug concentrations can be monitored for many aeDs (Table 3). I will assess serum concen- trations when: • Starting a new aeD in a difficult to control patient • Toxicity is suspected at a relatively low dose • abandoning an aeD due to poor seizure control. although uncommon and often not reported, liv- er, kidney, bone marrow, immune, and urinary cal- culi problems are possible consequences of aeD administration. Therefore, the following are recom- mended, at minimum, every 6 to 12 months based on therapy and patient needs: • Physical examination • Serum biochemical profile • Complete blood cell count • urinalysis. View a video showing a seizure in a dog at todaysveterinarypractice.com/resources.asp . TVP_2014-0506_Seizure Patient.indd 35 5/24/2014 10:44:52 AM