A new clinical trial at Colorado State University’s College of Veterinary Medicine is studying the effects of the transdermal form of mirtazapine as an appetite stimulate in cats with chronic kidney disease. Mirtazapine, commonly used in human medicine as an antidepressant, has been shown to be effective in increasing weight and appetite while decreasing vomiting in cats with chronic kidney disease. Although effective, many pet owners have difficulty administering pills to their cat. Therefore, Jessica Quimby, DVM, Ph.D., Dipl. ACVIM, an assistant professor at the college, wants to focus on the transdermal form of the drug. The study builds on five previous studies into whether a transdermal gel works and how the appetite stimulant can improve nutrition for cats, who are known to become picky eaters as their kidney disease progresses. “With most drugs there’s information about how to use it in humans and in dogs, but there’s almost never information about how to use it in cats, so typically when we start with a drug, we have to start at the very beginning and learn how to use it in healthy cats before we can understand how to use it in sick cats,” said Dr. Quimby, who leads the chronic kidney disease program within the Center for Companion Animal Studies at CSU. “We’re very excited about this trial because it takes us to that next level, which is using the transdermal gel in cats with kidney disease. They have a very picky appetite. They get very thin as their muscles atrophy. They’re basically starving to death, which is a really hard thing to watch.” Quimby will be enrolling 20 cats with early to moderate kidney disease with a picky appetite. Quimby’s own cat, Sophie, will also be a part of the clinical trial, according to CSU. The study involves clients bringing their cat to the CSU Veterinary Teaching Hospital for three visits and administering a gel to the ear for a total of six weeks. There are two treatment periods: the placebo transdermal gel and the mirtazapine transdermal gel. Cats will receive both in a randomly determined order. During the two transdermal treatment periods (placebo or mirtazapine) clients will administer the gel daily for three days then every other day for three weeks, fill out a daily log sheet and then bring their cat in for the hospital visit on the last day of gel administration. During this day, the cat will get a physical exam and weight, and have a blood sample drawn to check kidney values and to measure how much mirtazapine is in the cat’s body. All costs of the visits and the gel medication are covered by the study, which is funded by the Winn Feline Foundation, according to CSU. “We ask ‘What can we do to make them feel better?’ And that’s when an appetite stimulant can help so they don’t get super-skinny,” Quimby said. “As an owner, if your kitty’s not eating, it becomes a horrible struggle and that’s when it may come time to say goodbye, and that’s a very emotional issue.”
