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.
Lécuyer
Manon
M
Centre Hospitalier Universitaire Vétérinaire (CHUV), Faculty of Veterinary Medicine, University of Montreal, C.P. 5000, Saint-Hyacinthe, Quebec. manon.lecuyer@umontreal.ca
Prini
Sabrina
S
Dunn
Marilyn E
ME
Doucet
Michele Y
MY
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