Page 1473 - Clinical Small Animal Internal Medicine

159 Atopic Dermatitis 1411

(e.g., metoclopramide, metronidazole) as concurrent 24 hours and can provide therapy for an average of 4–8
VetBooks.ir administration may increase side‐effects. weeks, at which time it may be repeated. This therapy is
considered to be safe and is intended for both short- and
As opposed to glucocorticoids, which cause a rapid
reduction in pruritus, there is a lag associated with ciclo-
injection site discomfort, and lethargy are most commonly
sporin administration and clinical improvement. long-term use. Side effects are minimal; vomiting, diarrhea,
Maximal benefit is typically noted within about 4–6 reported and tend to be self-limiting in nature. It may be
weeks. At that time, if the patient is sufficiently comfort- used in dogs of any age, including those with concomitant
able, the medication may be tapered. diseases. There are no drug-drug interactions reported
thereby adding to Cytopoint’s robust safety profile. As this
Oclacitinib is a caninized mAB, it should only be administered in dogs.
Oclacitinib (Apoquel® Zoetis, New Jersey, USA) is a
novel Janus kinase inhibitor approved for dogs in the Miscellaneous Therapies
USA and Europe to control the pruritus associated with Many additional therapeutic interventions have been
allergic dermatitis in general and, specifically, atopic investigated for controlling pruritus associated with
dermatitis. Oclacitinib rather specifically inhibits atopic dermatitis in the dog. There is some evidence
production of IL‐31 from T cells in the dog. to support administration of recombinant interferons
This targeted therapeutic is similar to other tyrosine (either recombinant feline INF‐omega or recombinant
kinase molecules which have shown some benefits in the canine INF‐gamma); these injections have shown mod-
treatment of atopic dermatitis (e.g., masitinib), but the erate efficacy and a good safety profile in several allergic
safety profile is markedly enhanced. In a recent study, side‐ dogs. However, products are not necessarily available
effects were reduced compared to either glucocorticoids or worldwide. Other therapies such as azathioprine, various
ciclosporin even when the medication was administered cyclooxygenase/cyclooxygenase‐lipoxygenase inhibi-
long term. Vomiting and diarrhea were the most frequent tors, and pentoxifylline have been evaluated but have not
side‐effects reported but were typically transient and self‐ shown appreciable efficacy in atopic dogs.
limiting and did not require additional therapy or with-
drawal of medication. Minimal changes were noted on Allergen‐Specific Immunotherapy
bloodwork and urinalysis, with values remaining typically
within the normal range. Decrease in white blood cells was As opposed to addressing strictly the clinical signs asso-
noted in some patients, along with increased cholesterol ciated with atopic dermatitis, allergen‐specific immuno-
and lipase in others; however, neither fell outside a normal therapy aims to address the underlying immunologic
reference range. Efficacy for control of pruritus associated dysregulation which is part of the disease pathogenesis.
with atopic dermatitis is considered excellent in most dogs. Although the exact mechanism of action is uncertain,
Dosing is recommended at 0.4–0.6 mg/kg PO q12h for successful therapy may lead to a more “normalized”
the first two weeks, and then q24h long term. Increase in immunologic response to allergen exposure. This was
pruritus is commonly noted as the frequency of adminis- documented in one study where dogs that responded
tration is reduced to once daily; however, care should be favorably to therapy showed increases in less inflamma-
taken to not administer the dose twice daily longer than tory cytokines (IL‐10) and regulatory T cells.
the recommended two weeks because of increased risk Allergen‐specific immunotherapy is a “cocktail” of
for concerning, long‐term side‐effects. The increase in extracts of various environmental allergens based on the
pruritus is likely because the drug has a rather short results of allergen testing (see above). Although no well‐
serum half‐life and dividing the once‐a‐day dose to controlled clinical studies have established an ideal treat-
twice‐a‐day administration may help control the pruri- ment protocol, formulation, or administration schedule
tus flare in some patients. Oclacitinib has a very rapid for immunotherapy, benefits do appear to be noted in
onset, often markedly decreasing pruritus within the some dogs and cats with atopic dermatitis. Efficacy,
first one to two doses. It has not been extensively evalu- however, does appear to be less when compared to other
ated in cats with allergic skin disease and its use in this options (e.g., glucocorticoids, ciclosporin, oclacitinib).
species is not currently recommended. Based on anecdotal reports, approximately 50–75% of
dogs and cats with atopic dermatitis show beneficial
Lokivetmab results with immunotherapy administration. As the ther-
Lokivetmab (Cytopoint, Zoetis)is the first anti-IL31 mono- apy aims at changing the underlying immune response,
clonal antibody (mAB) licensed for the treatment of allergic results may take several months to be apparent. Clinical
and atopic dermatitis in dogs. The injection is administered improvements may initially be seen within the first 3–6
subcutaneously at a minimum dose of 2 mg/kg under the months but maximal benefits may not be noted until
direction of the veterinarian. It can provide efficacy within 12–18 months. Most patients require the addition of