Oclacitinib

Oclacitinib (brand name Apoquel) is a veterinary medication used in the control of atopic dermatitis and pruritus from allergic dermatitis in dogs at least 12 months of age. Chemically, it is a synthetic cyclohexylamino pyrrolopyrimidine janus kinase inhibitor that is relatively selective for JAK1. It inhibits signal transduction when the JAK is activated and thus helps downregulate expression of inflammatory cytokines. While oclacitinib is effective, its long-term safety is currently unknown. Oclacitinib (brand name Apoquel) is a veterinary medication used in the control of atopic dermatitis and pruritus from allergic dermatitis in dogs at least 12 months of age. Chemically, it is a synthetic cyclohexylamino pyrrolopyrimidine janus kinase inhibitor that is relatively selective for JAK1. It inhibits signal transduction when the JAK is activated and thus helps downregulate expression of inflammatory cytokines. While oclacitinib is effective, its long-term safety is currently unknown. Oclacitinib was approved by the FDA in 2013. Oclacitinib is labeled to treat atopic dermatitis and itchiness (pruritus) caused by allergies in dogs, though it has also been used to reduce the itchiness and dermatitis caused by flea infestations. It is considered to be highly effective in dogs, and has been established as safe for at least short-term use. Its efficacy equals that of prednisolone at first, though oclacitinib has been found to be more effective in the long term in terms of itchiness and dermatitis. It has been found to have a faster onset and cause less gastrointestinal issues than cyclosporine. While safe in the short term, oclacitinib's long-term safety is unknown. While some say it is best only for acute flares of itchiness, others claim that it is also useful in chronic atopic dermatitis. There is some off-label use of oclacitinib in treating asthma and allergic dermatitis in cats, but the exact efficacy has not been established. Oclacitinib is not labeled for use in dogs younger than one due to reports of it causing demodicosis. It should also be avoided in dogs less than 3 kg (6.6 lb). Most of the other contraindications are avoiding cases where a potential side effect exacerbates a pre-existing condition: for example, because oclacitinib can cause lumps or tumors, it should not be used in dogs with cancer or a history of it; because it is an immune system suppressant, it should not be used in dogs with serious infections. Oclacitinib, by virtue of its low plasma protein binding, has little chance of reacting with other drugs. Nonetheless, concurrent use of steroids and oclacitinib has not been tested and is thus not recommended. Oclacitinib lacks the side effects that most JAK inhibitors have in humans; instead, side effects are infrequent, mild, and mostly self-limiting. The most common side effects are gastrointestinal problems (vomiting, diarrhea, and appetite loss) and lethargy. The GI problems can sometimes be alleviated by giving oclacitinib with food. New cutaneous or subcutaneous lumps, such as papillomas, can appear, and dogs face an increased susceptibility to infections such as demodicosis. There is a transient decrease in neutrophils, eosinophils, and monocytes, as well as in serum globulin, while cholesterol and lipase levels increase. The decrease in white blood cells lasts only around 14 days. None of the increases or decreases are clinically significant (i.e. none push their corresponding values out of normal ranges). Less common side effects of oclacitinib include bloody diarrhea; pneumonia; infections of the skin, ear, and/or urinary tract; and histiocytomas (benign tumors). Increases in appetite, aggression, and thirst have also been reported.