Dermatologic Drugs and Preparations

Flashcards about systemic antipruritics, topical therapy, antibiotics, antifungals, and other dermatological treatments for veterinary medicine.

What is the significance of the summation effects/threshold phenomenon in veterinary dermatology?

It explains how multiple factors (e.g., flea allergies, infections) can combine to exceed the pruritic threshold, leading to itching in animals.

Why is there no 'perfect drug' for antipruritic therapy in veterinary medicine?

Each antipruritic drug has its own pros and cons, and the most suitable drug varies depending on the patient.

What are some systemic antipruritic drugs?

Glucocorticoids, cyclosporine, oclacitinib (Apoquel), ilunocitinib (Zenrelia), and lokivetmab (Cytopoint).

What is the mechanism of action of cyclosporine?

Cyclosporine binds to cyclophilin, which inhibits calcineurin, subsequently reducing the production of various interleukins and cytokines like IL-2, IL-4, IL-5, and TNF-α.

What are some adverse effects of cyclosporine?

Vomiting, diarrhea, anorexia, opportunistic infections, gingival hyperplasia, altered glucose metabolism, hepatotoxicity, and nephrotoxicity.

What should be considered regarding compounded formulations or generic versions of cyclosporine?

Compounded formulations are NOT bioequivalent, and generic formulations may have variability in bioequivalence. Starting with the name brand and then switching is suggested.

What is the mechanism of action of oclacitinib (Apoquel)?

Oclacitinib is a Janus kinase (JAK) inhibitor, primarily JAK1, that inhibits the intracellular signaling of pruritogenic cytokine IL-31, and also inhibits other cytokines, providing both anti-inflammatory and antipruritic effects.

What is a consideration for using Oclacitinib (Apoquel) in cats?

It is not approved for use in cats, and its safety is not well-established. There have been reports of fatal disseminated toxoplasmosis in FIV+ cats.

What is a contraindication for Oclacitinib (Apoquel) regarding age?

It should not be given to dogs less than 1 year old due to the association with severe secondary infections.

When was Ilunocitinib (Zenrelia ) launched and what is its mechanism of action?

Ilunocitinib (Zenrelia ) was launched in September 2024, with a mechanism of action similar to oclacitinib.

What is the mechanism of action of lokivetmab (Cytopoint)?

Lokivetmab is a genetically engineered monoclonal antibody that binds to IL-31, preventing it from interacting with its receptor, and has a VERY specific effect and immunosuppression is not generally expected.

What are some potential adverse effects of steroids in controlling generalized pruritus?

PU/PD/PP, UTI, skin infections, adrenal gland suppression, liver adverse effects, diabetes, calcinosis cutis, and GI ulcers.

What is the potential role of antihistamines in managing pruritus?

They may blunt histamine-mediated effects of mast cell degranulation, potentially useful as steroid-sparing agents or as preventative therapy, but probably won’t stop a full-blown pruritic attack.

What are the considerations when choosing topical therapy formats?

Shampoos/rinses/dips are good for widespread disease, wipes are great for focal lesions, sprays/mousses are good for limited areas, and creams/gels/lotions are for focal lesions too.

What are the concerns of topical steroids?

Like systemic steroids, topical steroids still come with side effects such as cutaneous atrophy, calcinosis cutis, comedones, and milia.

What is the mechanism of action of Tacrolimus?

Inhibits calcineurin, like cyclosporine and is an antipruritic, anti-inflammatory and immunomodulatory agent also for autoimmune/immune-mediated dz.

What is the mechanism of action of Chlorhexidine?

Binds to negatively charged bacterial cell surfaces and membranes, disrupting their integrity, and it works very well for bacterial and yeast dermatitis.

What is the mechanism of action of Benzoyl Peroxide?

Releases active free-radical oxygen species and oxidize bacterial proteins, and it is best for greasy skin or crusty pyoderma and Demodex.

What is the mechanism of action of Azoles and Terbinafine?

They inhibit the synthesis of ergosterol, a major component of fungal cell membranes which acts against yeast and dermatophytes.

What is the general treatment period for superficial and deep pyoderma with systemic treatment?

Superficial pyoderma should be treated 1–2 weeks post complete clinical cure or 3-4 weeks, whereas deep pyoderma should be treated 3–4 weeks post complete clinical cure or 8-12 weeks.

What is the most common bacterial cause of superficial pyoderma in dogs?

Staphylococcus pseudintermedius.

What is a take home message regarding systemic antipruritics?

Know the side effects and contraindications.

What is a take home message regarding antifungals

Antifungal side effects, drug interactions, and instructions for clients.