Anti-Pruritic Medications

Question 1

What are the 4 main anti-pruritic drugs used in dermatology?

Answer 1

1. Apoquel (Oclacitinib)
2. Cytopoint (Lokivetmab)
3. Cyclosporin (Atopica)
4. Prednisone/Prednisolone

Question 2

What is the mediator of pruritis? How does this work?

Answer 2

IL-31

activates the JAK/STAT pathway, causing the release of pro-inflammatory cytokines —> JAK dimerizes in response to IL-31, which activates STAT

Question 3

How does the MOA of Apoquel and Cytopoint compare?

Answer 3

Apoquel - JAK inhibitor, preferentially targets JAK1 (the receptor for IL-31) = no activation of JAK/STAT

Cytopoint - monoclonal antibody binds to IL-31 and prevents it from activated JAK/STAT

Question 4

How is prednisone used to treat pruritus?

Answer 4

use a specific dose (1.1 mg/kg) to inhibit inflammation-associated molecules and up-regulate anti-inflammatory mediators, like lipocortin (annexin) 1

• NOT IMMUNOSUPPRESSIVE DOSE

Question 5

What is the MOA of Cyclosporin?

Answer 5

calcineurin inhibitor suppresses IL-2, which blocks the proliferation of T-cells, thereby reducing inflammation and allergic response

Question 6

How are the 4 anti-pruritic medications administered?

Answer 6

1. Apoquel - PO, BID for 2 weeks then SID
2. Cytopoint - SQ, given once every 4-8 weeks
3. Prednisone - PO, dose and taper depending on severity of disease
4. Cyclosporin - PO, BID and tapered for maintenance

Question 7

How does the onset of the anti-pruritic medications differ?

Answer 7

• Prednisone, Cytopoint, Apoquel = quick, usually within 24 hours
• Cyclosporin - 4 weeks to reduce pruritus in dogs and 2-3 weeks in cats

Question 8

How does the cost of the anti-pruritic medications differ?

Answer 8

• CHEAP = Prednisone
• MODERATE = Apoquel, Cytopoint
• EXPENSIVE = Cyclosporin, especially in large dogs

Question 9

What are 3 side effects associated with Apoquel administration? In what patients is it contraindicated?

Answer 9

1. increase susceptibility to Demodex and other infections
2. neoplasia exacerbation
3. GI effects - V+, D+

patients less than 1 y/o –> Demodectic mange, severe pneumonia

Question 10

What side effects are associated with Cytopoint administration?

Answer 10

GI upset

• overall, it is l well-tolerated

Question 11

What is the main side effect associated with Cyclosporin administration? What else is seen?

Answer 11

GI upset

• increased hair growth (hirsutism)
• papillomatosis
• gingival hyperplasia
• NO MYELOSUPPRESSION

(resolve after cessation of use)

Question 12

What drug does Cyclosporin typically interact with? How can dose be lowered?

Answer 12

Ivermectin - inhibits P-glycoprotein (MDR1) at the BBB

Cyclosporin in a CYP450 substrate - give with Ketoconazole, a CYP450 inhibitor

Question 13

What are some side effects associated with Prednisone administration?

Answer 13

• PU/PD, polyphagia
• behavioral changes
• GI ulceration
• hepatopathy
• DM, hyperlipidemia
• decreased thyroid hormone
• delayed wound healing, calcinosis cutis, cutaneous atrophy, comedones
• secondary infections - demodicosis, toxoplasmosis, UTIs

Question 14

What drugs should Prednisone not be used in conjunction with?

Answer 14

NSAIDs - increases the risk of GI ulceration and renal failure

Question 15

How are the 4 anti-pruritic medications used in cats?

Answer 15

1. Apoquel - not labeled, administered with variable success, safe and effective doses not established
2. Cytopoint - antibody is caninized, so it is not used
3. Cyclosporin - used routinely
4. Prednisolone > Prednisone due to decreased GI absorption