Antipruritic treatments 3 Flashcards

1
Q

what are cyclosporines? use?

A
  • Cyclosporines are drugs initially developed to prevent organ transplant rejection.
  • Atopica is a cyclosporine licensed for the treatment of atopic dermatitis in the dog.
  • Effective treatment for environmental allergies in dogs and cats as long as other factors are ruled out
  • brand name generally better than generic
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2
Q

most common side effects of cyclosporines in dogs

A

intestinal upset, gingival hyperplasia and hypertrichosis.
- Papillomatosis is the next most common side effect that I see
- also, Plasmacytoma

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3
Q

petients where caution is necessary with cyclosporine

A

do not recommend the use of cyclosporine in patients with a history of tumours, and I use it with caution in the geriatric patient

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4
Q

contraindication for cyclosporine

A

contraindicated in the presence of neoplasia, patients with history of tumours

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5
Q

cyclosporine vs steroid treatment speed of response to therapy

A

It is important that the caregiver is advised that the rapid response to therapy obtained following initiation of steroid therapy is not seen with this drug.
- 4-6 wk minimum delayed response

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6
Q

cyclosporine dose, absorption, vomiting prevention, GI upset prevention

A
  • in dogs at 5 mg/Kg per day
  • Absorption is slightly better when administered on an empty stomach
  • given with maripotant for first 4 days of treatment to prevent vomiting
  • freezing the capsule before administration seems to reduce the incidence of GI upset
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7
Q

co-administration of cyclosporine with what other drug increases blood levels?

A
  • Co-administration of ketoconazole increases the Atopica blood levels and the dose should be decreased accordingly
  • This is a useful way of decreasing cost in the large dog
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8
Q

assessing the efficacy of cyclosporine over time? dose frequency?

A
  • If there is a 50% or greater response at 4-6 weeks, there is a good chance that the patient will continue to improve and that the treatment frequency or dose can be decreased.
  • Dose or frequency reduction is particularly important as the drug is quite expensive
    > Once there is a significant response, the frequency can be slowly decreased
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9
Q

what should cats have before starting cyclosporine? what cats should not receive this drug? diet considerations?

A
  • Cats should have a CBC done and be screened for FIV and FeLV prior to starting cyclosporine.
  • Cats should not be fed raw diets when on Atopica.
  • Cats at risk of contracting toxoplasma (outdoor cats, cats on a raw meat diet) should not be treated with this drug.
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10
Q

cyclosporine dose in cats

A

Syringe is dosed at 7 mg/Kg of cat

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11
Q

cyclosporine is approved for what conditions in cats

A

 Approved for allergic dermatitis manifested by excoriations, eosinophilic plaques, miliary dermatitis and self-induced alopecia

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12
Q

possible issue of cyclosporine in young animals

A

Safety of the treatment in dogs less than 6 months of age has not been established. As gingival hyperplasia is a potential side effect, the use of the drug in patients with immature dentition can lead to problems.

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13
Q

cyclosporine mechanism of action

A
  • Calcineurin inhibitor:
  • By inhibition of calcineurin, cyclosporine specifically inhibits T-cell function, and thus cell-mediated immunity, but has little immediate impact on humoral immunity
  • blocks transcription of T cell cytokines, such as IL-2, important in the activation and proliferation of T-lymphocytes
  • also affected are interleukin 4, TNF-alpha, and interferon gamma
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14
Q

when to discontinue cyclosporine use in cats

A

The owner should be advised to discontinue if there is anorexia and/or weight loss as hepatic lipidosis has been reported in cats on Atopica Cat

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15
Q

tacrolimus - what is this drug? use? pros and cons?

A
  • Like cyclosporine, tacrolimus is a calcineurin inhibitor, but with better tissue penetration
  • alternative to steroids
  • applied twice daily for the first week and then in reduced frequency.
  • slow onset, not for flares
  • initially application may lead to a burning sensation
  • The patient should not be allowed to lick the area of administration for at least 20-30 minutes and small pets in particular should be watched to avoid ingestion as toxicity can occur.
  • wear gloves when applying
  • May not be cost effective unless there is clear evidence of thinning of the skin with steroid
    treatment.
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16
Q

antihistamines use for pruritus

A
  • not effective in ‘putting out the fire’
  • useful in some cases:
  • To control after the pruritus has been relieved (eg. with steroids)
  • to reduce the steroid dose
  • early in ‘season’ in dogs with seasonally recurring dermatitis
  • very mildly affected individuals
17
Q

which antihistamine is best to use for pruritus? cautions?

A
  • best one is the one that works best
  • Try each antihistamine for a period of 7-14 days each to assess response
  • If using over the counter products, be sure to warn owners not to accidentally administer products that also contain decongestants, acetaminophen and the like.
  • may have synergy with fatty acid supplementation
18
Q

fatty acid supplementation for pruritus? use? how long do they take?

A
  • 4-6 weeks to take effect
  • more useful as adjunctive therpy
  • “no evidence of superiority of any particular EFA combination, dose, ratio or formulation to improve skin and coat quality”
  • supplement in diet
  • high fatty acid diets recommended for non-food induced atopic dermatitis
19
Q

gabapentin use for pruritus?

A
  • This treatment has not been critically evaluated to date but is starting to gain traction in cases of intractable pruritus.
  • mechanism of action is unknown, it appears to act where the itch pathways synapse by inhibiting the release of excitatory mediators
    > The sensation of itch and pain are shared by the same neurons
20
Q

Pentoxifylline, Misoprostol use for pruritus?

A

There is some evidence to support the use of these medications.
> suppress numerous cytokines, decreases leukocyte adhesion and aggregation and inhibits B and T cell activation

21
Q

maropitant for pruritus use? mechanism

A
  • Substance P is a mediator of pruritus.
  • In people, an increase in the expression of its receptor, neurokinin-1, has been reported on keratinocytes in pruritic skin diseases
  • Maripotant is a veterinary product that is a potent NK-1 receptor antagonist and is sold as Cerenia
    > labeled for treatment of acute vomiting
  • trials for cases of severe intractable pruritus in dogs
22
Q

Allergic conjunctivitis treatment options

A
  • Cool compresses to eyes are an easy and often highly effective treatment for itchy eyes.
  • some success with topical ocular NSAID, ketorolac
23
Q

Allergic Otitis treatment options

A
  • Gentle ear treatments are the mainstay of allergic ear treatment.
  • remarkable success with compounded 2% Burows solution, 1% hydrocortisone, in Propylene Glycol
  • Various treatments are available for the treatment of otitis externa in dogs and cats. Most are a combination of antibiotics, antifungal agents and steroids
24
Q

Spot-On products for pruritus?

A

a complex lipid mixture (Allerderm Spot-on®) has been shown recently to help restore pre-existing ultrastructural lipid anomalies in a small number of dogs with atopy

25
Q

Shampoo therapies for pruritus? use and efficacy?

A
  • Bathing at least once weekly with a mild, non-irritatingshampoo and lukewarm water is likely to be beneficial
  • The intensity and frequency of bathing may be the most important factor in relieving pruritus
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  • Bathing offers a direct soothing effect to the skin, the physical removal of surface allergens and microbes and an increase in skin hydration
  • The shampoo choice varies with the individual pet’s coat condition
  • Ingredients that theoretically relieve pruritus include sulphur and salicylic acid, selenium sulfide, oatmeal and hydrocortisone
  • If a concurrent microbial dermatitis is present, the use of shampoo containing antimicrobial ingredients such as chlorhexidine, ketoconazole, miconazole, climbazole or cetrimide are useful in controlling “flare factors.”