Doses - MEPHENYTOIN
Dogs: 
a) For adjunctive therapy of refractory seizures (not controlled with Phenobarbital orprimidone and potassium bromide): Initially, 10 mg/kg PO every 8 hours; increasedosage to achieve a nirvanol (active metabolite) blood level of 25 - 40 micrograms/ml. Steady state is reached in about 6 days. (Schwartz-Porsche 1992)
b) As a second-line agent when first line drugs are not effective: 10 mg/kg tid. Therapeuticblood levels as above. (Neer 1994)
Monitoring Parameters - 1) Level of seizure control; sedation/ataxia; 2) CBC with platelets on aregular basis; 3) Serum drug levels until therapeutic levels attained, then if signs of toxicity or lackof seizure control occur
Client Information - Notify veterinarian if dog becomes anorexic, lethargic, ataxic, has abnormalbleeding/bruising, or if seizures are not adequately controlled. The importance of regular dosing isimperative for successful therapy.
Dosage Forms/Preparations/FDA Approval Status/Withholding Times - Veterinary-Approved Products: None