Final Exam Flashcards
The first-line for general immunosuppression is typically
High dose glucocorticoids
This drug is ~7-8x more potent than Prednisone
Dexamethasone
Side effects from steroids
PU, PD, and panting
May be used as adjunctive therapy (to reduce amount of glucocorticoid needed) or as solitary therapy for certain diseases.
Other immunosuppressive drugs
Targets for immunosuppressive drug action
Antimetabolites and T-cell inhibitors
Impair nucleic acid synthesis (DNA) particularly in rapidly dividing
immune cells, and can block signaling on T-cells
Antimetabolites
This antimetabolite is given orally and should not be used in cats due to toxicity in the liver and bone marrow
Azathioprine
This antimetabolite is less commonly used, given orally, and often reserved for immune disease unresponsiveness to other therapies
Mycophenolate mofetil
This antimetabolite is often started with prednisone for difficult immune diseases
Azathioprine
This antimetabolite is administered orally and has relatively few side effects
Leflunomide
T-cell inhibitors
Cyclosporine and Tacrolimus topical
Atopica, Neoral, and Sandimmune are all bioequivalent
FALSE, Sandimmune isn’t bioequivalent to the other two
Topical used in management of dermatologic dz and
perianal fistulas.
Tacrolimus topical
A polypeptide that blocks cyclophilin/calcineurin which reduces T-cell activation & response, inhibits production of various cytokines to alter function of other WBCs.
Cyclosporine
Used topically on eye to treat keratoconjunctivitis sicca (KCS), used systemically to treat perianal fistules, or as an adjunct with glucocorticoids for other immune diseases
Cyclosporine
Tacrolimus topical has a slightly different target than Cyclosporine but essentially the same mechanism of action
TRUE
Have a relatively more narrow therapeutic index than other drugs and may require special handling
Cancer chemotherapy drugs
When handling chemo should you wear protective equipment?
Yes. Gloves, mask, gown
Where the cancer started
Primary cancer
Foci of cancerous cells distant from the original neoplasm
Metastases or “mets”
Is it possible to find mets without knowing where the primary cancer is?
Yep
Complete eradication of the cancer
Cure
- Although this is sometimes possible, it is rarely the goal of therapy in veterinary oncology.
- Cures often involve extremely aggressive treatment protocols
Decrease in or disappearance of signs and symptoms of cancer
Remission
- Can be partial or complete
- May be undetectable by available tests but it is not gone completely
Treatment aimed at preserving the quality of life of the patient without specific focus on prolongation of life
Palliative care
Palliative care when the decision has been made to cease life- extending treatment and the patient’s further life expectancy is short
Hospice care
Drug that is capable of causing tissue necrosis when extravasated
Vesicant
Administration of the drug outside of the blood vessel
Extravasation
What does BAG stand for and which do we not worry about as much in veterinary medicine?
Bone marrow, Alopecia, GI
We don’t really worry about alopecia
Most common of the adverse effects of chemo dugs
Gastrointestinal signs
Are antiemetics used before or during treatment when nausea is expected?
Yes
Lowest neutrophil count
Nadir
If neutropenia is severe what do you do?
Prophylactic antibiotics may be started
What kinds of dogs show more hair loss?
Dogs with continuously growing coats (poodles, terriers, Old English sheepdogs)
How do cats demonstrate alopecia?
Whiskers may fall out
Systemic adverse event that can be life-threatening and occurs
when there is a high tumor burden and treatment causes massive cell death and release of intracellular substances from the dying cancer cells
Acute tumor lysis syndrome
To reduce resistance developing in the cancer cell population and minimize toxicity to the patient
Multi-drug chemotherapy protocol
Differs from traditional protocols in that lower doses of drugs are given over longer periods of time
Metronomic chemotherapy
Dilation of the pupil
Mydriasis
Constriction of the pupil
Miosis
Most common reasons for using ophthalmic drugs
Dilation/constriction of the pupil Decrease aqueous fluid production or IOP Increase tear production Decrease inflammation Treat infection Analgesia
What route of administration would you use to reach the anterior portion of the eye?
Topical
What route of administration would you use to reach the posterior portion of the eye?
Systemic
Give one drop at a time and then wait ____ and then give the next drop
5 minutes
Pupil dilation and constriction are controlled by the actions of
The PSNS and SNS
Direct acting parasympathomimetic, causes miosis that lasts about 2-6 hours, commonly used to localize parasympathetic lesions to the iris sphincter.
Pilocarpine
Pilocarpine is used to treat glaucoma and dry eye that is due to neurogenic causes.
FALSE. Uncommonly used to treat either
Indirect acting parasympathomimetics that increase uveoscleral drainage for up to 48 hours
Demecarium and Physostigmine
Indirect acting parasympathomimetic uncommonly used as a glaucoma preventative
Demecarium
Indirect acting parasympathomimetic that readily crosses the BBB
Physostigmine
-Not commonly used systemically, be cautious of the amount of systemic absorption in small patients
Indirect acting parasympathomimetic that causes miosis that lasts for a long time (>12 hours)
Echothiophate
Will cause paralysis of the iris sphincter muscle and ciliary body – leading to potent mydriasis
Blocking the PSNS
Direct acting parasympatholytic that causes mydriasis and cycloplegia. Onset of ~1hr which can last 120+ hours
Atropine
Direct acting parasympatholytic that basically acts the SAME way as Atropine but has a faster onset (~15-30 mins) and shorter duration (~3-12 hours)
Tropicamide
Used as a mydriatic/cycloplegic to reduce pain associated with uveitis and may be used to break up/prevent synechiae when there is inflammation of the eye
Atropine
Cycloplegia is a major issue in what species?
Horses
What can be the issue with giving atropine to cats?
Bitter taste
Tropicamide is less bitter than atropine but still may cause hypersalivation in cats
TRUE
Atropine and Tropicamide should be used in primary glaucoma
Figgity figgity FALSE
These drugs also cause decreased production of aqueous humor (by reducing cAMP levels) and are sometimes used for that purpose as adjunct therapy in the management of glaucoma
Adrenergic agents
Direct acting a1 agonist that will cause mydriasis in the dog but can take some time to do so and is not very effective for pupil dilation in cats, horses, or cattle. It is used perioperatively for some surgeries to reduce local bleeding (vasoconstriction) and used sometimes in the diagnosis and localization of sympathetic lesions.
Phenylephrine
Nonselective beta-adrenergic antagonist thought to inhibit cAMP production leading to decreased aqueous humor formation, though there may also be some effect on Na/K/ATPase which also
reduces aqueous production. Often used in the chronic management of glaucoma. May cause miosis but not potent. Bradycardia could be seen if there is sufficient systemic absorption
Timolol
These block the carbonic anhydrase enzyme which results in decreased formatin of bicarbonate in the non-pigmented ciliary epithelium
Carbonic anhydrase inhibitors
Can be used topically or systemically in the management of glaucoma, however topical usage will reduce the potential for systemic adverse effects.
Carbonic anhydrase inhibitors
This CAI is effective in dogs and cats (less so in horses). It may cause more stinging than brinzolamide
Dorzolamide
This CAI is not effective in cats
Brinzolamide
These agents are analogs of Prostaglandin F which very selectively stimulate Prostaglandin F receptors in the eye to increase uveoscleral outflow of aqueous which reduces IOP. Very potent in reducing IOP in dogs but have questionable efficacy in cats and horses. Qork rapidly (within 30-120 minutes) and are synergistic with other anti-glaucoma medications. Adverse effects include miosis, so they should not be used in anterior lens luxation. Prostaglandins may exacerbate ocular inflammation.
Prostaglandin analogs
The most commonly used prostaglandin analog
Latanoprost
Most commonly needed to treat KCS and some immune-mediated corneal diseases
Immunosuppression of the eye
Typically the ‘first line’ for treatment of chronic immune-mediated ophthalmic diseases. Act by inhibiting T-lymphocytes. Longterm (or lifelong) therapy may be necessary. Accumulate in the corneal stroma and also penetrate the conjunctiva to be taken up into the lacrimal gland. Cause local immunosuppression so are contraindicated in the face of active infection. Avoid repeated contact with skin (of the person administrating the drug).
Cyclosporine
Has the same mechanism but possibly different receptor sites than Cyclosporine and sometimes works from some patients non-responsive to Cyclosporine therapy. Generally reserved as a second-line of therapy.
Tacrolimus
Inflammation in the anterior portion of the eye can be reduced with the use of
Glucocorticoids or NSAIDs
Provide more potent anti-
inflammatory effects than NSAIDs, however they also are more likely to impair healing and immune response to infection. Should NOT be used in the face of active infection or corneal ulcers. Use with caution in cats who may have chronic herpesvirus infx
Glucocorticoids
-commonly used agents: prednisolone acetate, dexamethasone sodium phosphate and hydrocortisone
Penetrates into the anterior chamber and so is better for treating anterior uveitis
Prednisolone acetate
Does not penetrate as well and so may be better for treating corneal inflammation
Dexamethasone sodium phosphate
Commonly combined in ‘triple antibiotic’ mixtures
Hydrocortisone
These drugs work through inhibition of COX-2 but may have some anti-COX-1 activity as wel. Used to treat ocular inflammation, particularly in situations where glucocorticoids are contraindicated.
NSAIDs
Two commonly used topical ophthalmic NSAIDs
Flurbiprofen and Diclofenac
Rare anaphylactic reaction in some cats to
Polymyxin B or Bacitracin
Topical ophthalmic antiviral agent
Gancyclovir
Systemic ophthalmic antiviral agent
Famcyclovir
Ophthalmic antifungal agent
Natamycin
Ophthalmic topical anesthetic, typically used to decrease corneal sensation to allow diagnostic evaluation.
Proparacaine
Inhibitor of appetite
Serotonin (5-HT1)
Stimulants of appetite
Norepinephrine (alpha-2)
Dopamine (D1 receptors)
GABA (by inhibiting the satiety center)
These drugs work by stimulating GABA which inhibits the satiety center to increase appetite, more effective in cats than dogs, generally useful for short term only, and most common side effect is sedation
Benzodiazepines (Diazepam, Midazolam)
Diazepam is typically given IV and Midazolam is given IM
TRUE
Oral use of this drug can cause idiosyncratic hepatotoxicity in cats
Diazepam
Appetite stimulation is observed at sub-hypnotic doses though the mechanism is not well understood but may involved stimulation of GABA and inhibition of 5-HT1. Given IV, provides a very short term increase in appetite.
Propofol
Repeated doses of this drug in cats can cause oxidative RBC injury and Heinz body anemia has been observed when it is used daily for >5 days
Propofol
Inhibit the satiety center by blocking 5-HT1 receptors
Serotonin antagonists
This appetite stimulant is effective in cats, not so much in dogs. Used orally, well absorbed, generally takes 2-3 days to see a response. Most common side effect is sedation.
Cyproheptadine
This appetite stimulant is a tricyclic antidepressant that blocks both 5-HT1 and 5-HT2 receptors and also increases NE
centrally. Used in dogs more than cats.
Mirtazapine
Drugs that induce emesis
Emetics
Drugs that suppress emesis
Antiemetics
Dogs have fewer Dopamine and Histamine receptors in the CRTZ, but more alpha-2 and serotonin receptors.
FALSE, cats
Receptors in the CRTZ that can stimulate vomiting
Serotonin (5-HT3)
Adrenergic (alpha-2)
Dopamine (D2)
Metabolic (toxins)
Most common peripherally acting emetic
Hydrogen peroxide 3%
Should you use Hydrogen Peroxide in cats?
Hell nah, higher risk of mucosal damage
Cause direct irritation to the oropharynx and gastric lining leading to stimulation of the emetic center and vomiting.
Peripherally acting emetics
Stimulate the vomiting center and tend to be more effective than peripheral emetics. Ideally used with toxin ingestion and vomiting needs to occur several times.
Centrally acting emetics
