Clinical efficacy and safety of transdermal methimazole in the treatment of feline hyperthyroidism.
Thirteen cats, newly diagnosed with hyperthyroidism, were treated with a transdermal formulation of methimazole at a dose of 5 mg (0.1 mL) (concentration of 50 mg/mL) applied to the internal ear pinna every 12 h for 28 d. Baseline hematologic and biochemical values, along with serum thyroxine (T4) levels, were obtained on presentation (day 0). Cats were evaluated at 14 d (D14) and 28 d (D28) following transdermal therapy. At each visit, a physical examination, a complete blood cell count, a serum biochemical analysis, and a serum T4 evaluation were performed. Ten cats completed the study. Clinical improvement, as well as a significant decrease in T4, was noted in all cats. Serum T4 measured at D14 and D28 were significantly lower at 27.44 nmol/L, s = 37.51 and 14.63 nmol/L, s = 10.65, respectively (P < 0.0001), as compared with values at D0 (97.31 nmol/L, s = 37.55). Only 1 cat showed a cutaneous adverse reaction along with a marked thrombocytopenia. The results of this prospective clinical study suggest that transdermal methimazole is an effective and safe alternative to conventional oral formulations.
Centre Hospitalier Universitaire Vétérinaire (CHUV), Faculty of Veterinary Medicine, University of Montreal, C.P. 5000, Saint-Hyacinthe, Quebec. manon.lecuyer@umontreal.ca
Manon
M
Lécuyer
Sabrina
S
Prini
Marilyn E
ME
Dunn
Michele Y
MY
Doucet
D000279:Administration, Cutaneous; D000818:Animals; D013956:Antithyroid Agents / Q000627:therapeutic use*; D001772:Blood Cell Count / Q000662:veterinary; D001774:Blood Chemical Analysis / Q000662:veterinary; D002371:Cat Diseases / Q000188:drug therapy*; D002415:Cats; D005260:Female; D006980:Hyperthyroidism / Q000188:drug therapy / Q000662:veterinary*; D008297:Male; D008713:Methimazole / Q000627:therapeutic use*; D011446:Prospective Studies; D012449:Safety; D013974:Thyroxine / Q000097:blood; D016896:Treatment Outcome
D013956:Antithyroid Agents; D008713:Methimazole; D013974:Thyroxine