Phenobarbital Transdermal Application

This owner-preferred method requires more bloodwork

Seizure medications tend to be lifelong treatments, but pilling most cats is not a pleasant experience for the cat or the owner. A study published in the Journal of Feline Medicine and Surgery looked at the transdermal (medication absorbed through the skin) application of the epilepsy medicine phenobarbital as an alternative.

Nine cats who were receiving phenobarbital for presumptive idiopathic epilepsy and had no deleterious effects from that drug were selected for the study. For the first 14 weeks, all the cats received their phenobarbital dosage orally. For weeks 15 through 28, the cats received transdermal phenobarbital (higher concentrations of the medication were used for the transdermal approach). Blood was drawn to verify blood serum concentrations at weeks 2, 14, 16, and 28 weeks, and dosages were adjusted.

When cats received phenobarbital orally, there was good correlation between the dose and the blood serum concentration. While on the transdermal therapy, however, there were more problems getting the dosage adjusted properly, so more bloodwork was necessary.

Still, despite the need for more frequent bloodwork, six of the nine cat owners preferred the transdermal application. If considering this approach, it’s important to understand that compounding pharmacies vary in their ability to create consistent batches of medication, making bloodwork checks important.n

J Feline Med Surg. 2019 Dec;21(12):1181-1187. doi: 10.1177/1098612X18823577. Epub 2019 Jan 28.