title: Evaluation of twice-daily lower-dose trilostane treatment administered orally in dogs with naturally occurring hyperadrenocorticism.
abstract: OBJECTIVE
  To evaluate effectiveness and incidence of adverse reactions to twice-daily lower-dose oral administration of trilostane in the treatment of dogs with naturally occurring hyperadrenocorticism (NOH).
  
  
  METHODS
  Clinical trial.
  
  
  METHODS
  47 dogs with NOH.
  
  
  METHODS
  47 dogs were treated orally with trilostane (0.21 to 1.1 mg/kg [0.1 to 0.5 mg/lb], q 12 h). All dogs were reevaluated at 2 weeks and 2 months, 38 dogs at 6 months, and 28 dogs at 1 year of treatment.
  
  
  RESULTS
  9 of 47 dogs had an adrenocortical tumor causing NOH, and all had good responses after 2 months (mean trilostane dosage, 0.89 mg/kg [0.40 mg/lb], q 12 h). All successfully underwent surgical adrenal tumor extirpation. Thirty-eight dogs had pituitary-dependent hyperadrenocorticism (PDH); 15 dogs did not require a dose increase during the study, and at each of 4 reevaluations, 10 of 15, 13 of 15, 14 of 15, and 11 of 11 had a good response. Twenty-three dogs with PDH had their dose or frequency of trilostane administration increased during the study. Mean trilostane dosage at 1-year reevaluation in dogs with a good response was 1.7 mg/kg (0.8 mg/lb), twice daily, or 1.1 mg/kg, 3 times daily. At each of 4 reevaluations, 17 of 23, 14 of 23, 17 of 23, and 13 of 17 dogs with PDH had a good response. Five dogs became ill because of trilostane-induced adverse effects, but only 1 required hospitalization.
  
  
  CONCLUSIONS
  Administration of initial lower doses of trilostane to dogs with NOH is effective.
authors.affiliation: Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616, USA. ecfeldman@ucdavis.edu
authors.forename: Edward C
authors.initials: EC
authors.lastname: Feldman
mesh_terms: D000284:Administration, Oral; D000308:Adrenocortical Hyperfunction / Q000188:drug therapy / Q000662:veterinary*; D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D013196:Dihydrotestosterone / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D004283:Dog Diseases / Q000188:drug therapy*; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule / Q000662:veterinary; D005260:Female; D008297:Male; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D013196:Dihydrotestosterone; C009954:trilostane