Updated: Dec 9, 2021
JAK1 & JAK3 inhibitor for treating pruritus in dogs.
New drug so full adverse effect profile is unknown. Most commonly reported adverse effects are gastrointestinal related (vomiting, diarrhea, inappetence), polydipsia, and lethargy. Serious adverse effects including susceptibility to infections (e.g., pneumonia, demodicosis), neoplasia, and skin disorders are possible.
Dosed twice a day for up to 2 weeks and then backed down to once daily.
Oclacitinib is FDA-approved in dogs (at least 1-year old) for the control of pruritus associated with allergic dermatitis and control of atopic dermatitis.
In a large (436 dogs), randomized, double-blinded, placebo-controlled, pre-authorization study evaluating the safety and efficacy of oclacitinib for the control of pruritus associated with allergic dermatitis, both owner- and veterinarian-scored visual analog scale scores for pruritus were significantly better for oclacitinib treated dogs versus those treated with placebo (Cosgrove et al. 2013a). Another similar study in 299 dogs with chronic atopic dermatitis found that when compared to the placebo group, treated dogs had significantly higher reductions in VAS scores (owner-scored) and Canine AD Extent and Severity Index (CADESI-02; dermatologist-scored) (Cosgrove et al. 2013b).
The product label states that it is not for use in dogs <12 months of age, those with serious infections, breeding dogs, or pregnant or lactating bitches. Additionally, oclacitinib is labeled that it may increase susceptibility to infection, including demodicosis, and exacerbate neoplastic conditions (Anon 2013a).
While not stated on the label, marketing information from the drug sponsor states that oclacitinib has been safely used in conjunction with vaccines (Anon 2013b). A pre-authorization vaccine response study concluded that at 3X (1.8 mg/kg) doses, there were adequate serological immune responses to a multivalent modified live vaccine (MLV) containing canine distemper virus (CDV), canine parvovirus (CPV), canine adenovirus (CAV), and canine parainfluenza virus (CPI), and to a killed-virus rabies vaccine. However at this dosage rate, 5 of 8 treated dogs developed enlarged lymph nodes, interdigital furunculosis, cysts and mild to severe pododermatitis. One dog was euthanized and was found to have had acute pneumonia and chronic lymphadenitis of mesenteric lymph nodes (Anon 2013c).
Due to its recent approval and limited clinical use, oclacitinib’s adverse effect profile is not fully known. Most commonly gastrointestinal effects (vomiting, diarrhea, anorexia), polydipsia or lethargy have been noted but other potentially serious adverse effects, including susceptibility to infections (e.g., pneumonia, demodicosis), neoplasia, and skin disorders are possible.