title: Hypokalemia and suspected renal tubular acidosis associated with topical carbonic anhydrase inhibitor therapy in a cat.
abstract: OBJECTIVE
  To describe the occurrence of hypokalemia, metabolic acidosis, and suspected renal tubular acidosis associated with the administration of topical ophthalmic carbonic anhydrase inhibitor (CAI) in a cat.
  
  
  METHODS
  A 2-year-old, 5.3 kg, male, castrated, domestic short-haired cat developed hyporexia 6 weeks after starting topical ophthalmic dorzolamide 2% therapy for treatment of ocular hypertension. Two weeks later, the cat was evaluated for severe weakness, cervical ventroflexion, and anorexia. Plasma electrolyte and acid-base measurement revealed hypokalemia (K+= 2.9 mmol/L; reference interval 3.8-5.4 mmol/L) and metabolic acidosis (plasma HCO3-= 9.8 mmol/L; reference interval 15-23 mmol/L) in the presence of a urine pH of 7.5 (reference interval 6.5-7.5). The pH abnormalities were consistent with a renal tubular acidosis. Clinical and biochemical abnormalities resolved with short-term supportive care, potassium supplementation, and discontinuation of dorzolamide therapy.
  
  
  CONCLUSIONS
  This is the first report of hypokalemia and metabolic acidosis associated with topical CAI therapy in a cat.
authors.affiliation: Department of Veterinary Clinical Sciences, Lloyd Veterinary Medical Center, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011.
authors.forename: Charlotte E
authors.initials: CE
authors.lastname: Thiessen
authors.affiliation: Department of Veterinary Clinical Sciences, Lloyd Veterinary Medical Center, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011.
authors.forename: Kyle L
authors.initials: KL
authors.lastname: Tofflemire
authors.affiliation: Department of Veterinary Clinical Sciences, Lloyd Veterinary Medical Center, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011.
authors.forename: Kelly M
authors.initials: KM
authors.lastname: Makielski
authors.affiliation: Department of Veterinary Clinical Sciences, Lloyd Veterinary Medical Center, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011.
authors.forename: Gil
authors.initials: G
authors.lastname: Ben-Shlomo
authors.affiliation: Department of Veterinary Clinical Sciences, Lloyd Veterinary Medical Center, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011.
authors.forename: R David
authors.initials: RD
authors.lastname: Whitley
authors.affiliation: Department of Veterinary Clinical Sciences, Lloyd Veterinary Medical Center, College of Veterinary Medicine, Iowa State University, Ames, IA, 50011. allbaugh@iastate.edu.
authors.forename: Rachel A
authors.initials: RA
authors.lastname: Allbaugh
mesh_terms: D000141:Acidosis, Renal Tubular / Q000139:chemically induced / Q000150:complications / Q000175:diagnosis / Q000662:veterinary*; D000818:Animals; D002257:Carbonic Anhydrase Inhibitors / Q000009:adverse effects*; D002371:Cat Diseases / Q000097:blood / Q000175:diagnosis*; D002415:Cats; D003937:Diagnosis, Differential; D007008:Hypokalemia / Q000139:chemically induced / Q000150:complications / Q000175:diagnosis / Q000662:veterinary*; D008297:Male; D009798:Ocular Hypertension / Q000188:drug therapy / Q000662:veterinary; D009883:Ophthalmic Solutions / Q000009:adverse effects; D013449:Sulfonamides / Q000009:adverse effects*; D013876:Thiophenes / Q000009:adverse effects*
chemical_list: D002257:Carbonic Anhydrase Inhibitors; D009883:Ophthalmic Solutions; D013449:Sulfonamides; D013876:Thiophenes; C062765:dorzolamide
keywords: complication; dorzolamide; feline; metabolic acidosis