ExoticRx · exoticrx.com/drugs/methimazole-transdermal
US brand names:Methimazole PLO gel
Methimazole Transdermal is dosed at 2.5–5 mg per cat Transdermal q12h in cats, per Sartor LL, Trepanier LA, Kroll MM, Rodan I, Challoner L. Efficacy and safety of transdermal methimazole in the treatment of cats with hyperthyroidism. J Vet Intern Med. 2004;18(5):651-655. | Lecuyer M, Prini S, Dunn ME, Douce MY. Clinical efficacy and safety of transdermal methimazole in the treatment of feline hyperthyroidism. Can Vet J. 2006;47:131-135. | Boretti FS, Sieber-Ruckstuhl NS, Schafer S, et al. Duration of T4 suppression in hyperthyroid cats treated once and twice daily with transdermal methimazole. J Vet Intern Med. 2013;27(2):377-381. doi:10.1111/j.1939-1676.2004.tb02601.x — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.878 (2026-08-01).. Verify against current literature before clinical use.
Same as oral methimazole. Transdermal delivery through pinna skin avoids GI side effects. Inhibits thyroid peroxidase.
Applied to inner pinna of cat ears. Alternating ears. Handler wears gloves. Less GI upset than oral. Erratic absorption reported. Monitor T4.
Species references:All Cat (Domestic) drugs
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| Species | Route | Dose | Frequency | Evidence | Source |
|---|---|---|---|---|---|
| Cat (Domestic) | Transdermal | 2.5–5 mg per cat | q12h | Strong | Sartor LL, Trepanier LA, Kroll MM, Rodan I, Challoner L. Efficacy and safety of transdermal methimazole in the treatment of cats with hyperthyroidism. J Vet Intern Med. 2004;18(5):651-655. | Lecuyer M, Prini S, Dunn ME, Douce MY. Clinical efficacy and safety of transdermal methimazole in the treatment of feline hyperthyroidism. Can Vet J. 2006;47:131-135. | Boretti FS, Sieber-Ruckstuhl NS, Schafer S, et al. Duration of T4 suppression in hyperthyroid cats treated once and twice daily with transdermal methimazole. J Vet Intern Med. 2013;27(2):377-381. doi:10.1111/j.1939-1676.2004.tb02601.x — Verified against Plumb's Veterinary Drug Handbook, 10th Ed, p.878 (2026-08-01). |
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View PlansSource citations and evidence levels available on the live page. Reference only — verify against current literature before clinical use.