Currently, such human drugs as benzodiazepines, cyproheptadine and mirtazapene are used to treat inappetence in cats. But they can sometimes have undesirable side effects. And, Aratana says on its website, they can have limited effectiveness and may be contraindicated for cats with some health issues. None are approved by the FDA for veterinary use.
Capromorelin is a small molecule that mimics ghrelin, a hormone produced by the stomach that causes a feeling of hunger.
Aratana tested capromorelin on 40 cats with kidney disease and found that those treated with a daily oral dose had increased food consumption and "significant increases in body weight" after 90 days.
Capromorelin could be especially helpful to cats with kidney and other chronic diseases and cats undergoing chemotherapy, recovering from surgery or approaching end of life.
A larger study of capromorelin will begin sometime in 2016.